/* Redis Sentinel implementation * * Copyright (c) 2009-2012, Salvatore Sanfilippo * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of Redis nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "server.h" #include "hiredis.h" #ifdef USE_OPENSSL #include "openssl/ssl.h" #include "hiredis_ssl.h" #endif #include "async.h" #include #include #include #include #include extern char **environ; #ifdef USE_OPENSSL extern SSL_CTX *redis_tls_ctx; extern SSL_CTX *redis_tls_client_ctx; #endif #define REDIS_SENTINEL_PORT 26379 /* ======================== Sentinel global state =========================== */ /* Address object, used to describe an ip:port pair. */ typedef struct sentinelAddr { char *hostname; /* Hostname OR address, as specified */ char *ip; /* Always a resolved address */ int port; } sentinelAddr; /* A Sentinel Redis Instance object is monitoring. */ #define SRI_MASTER (1<<0) #define SRI_SLAVE (1<<1) #define SRI_SENTINEL (1<<2) #define SRI_S_DOWN (1<<3) /* Subjectively down (no quorum). */ #define SRI_O_DOWN (1<<4) /* Objectively down (confirmed by others). */ #define SRI_MASTER_DOWN (1<<5) /* A Sentinel with this flag set thinks that its master is down. */ #define SRI_FAILOVER_IN_PROGRESS (1<<6) /* Failover is in progress for this master. */ #define SRI_PROMOTED (1<<7) /* Slave selected for promotion. */ #define SRI_RECONF_SENT (1<<8) /* SLAVEOF sent. */ #define SRI_RECONF_INPROG (1<<9) /* Slave synchronization in progress. */ #define SRI_RECONF_DONE (1<<10) /* Slave synchronized with new master. */ #define SRI_FORCE_FAILOVER (1<<11) /* Force failover with master up. */ #define SRI_SCRIPT_KILL_SENT (1<<12) /* SCRIPT KILL already sent on -BUSY */ /* Note: times are in milliseconds. */ #define SENTINEL_INFO_PERIOD 10000 #define SENTINEL_PING_PERIOD 1000 #define SENTINEL_ASK_PERIOD 1000 #define SENTINEL_PUBLISH_PERIOD 2000 #define SENTINEL_DEFAULT_DOWN_AFTER 30000 #define SENTINEL_HELLO_CHANNEL "__sentinel__:hello" #define SENTINEL_TILT_TRIGGER 2000 #define SENTINEL_TILT_PERIOD (SENTINEL_PING_PERIOD*30) #define SENTINEL_DEFAULT_SLAVE_PRIORITY 100 #define SENTINEL_SLAVE_RECONF_TIMEOUT 10000 #define SENTINEL_DEFAULT_PARALLEL_SYNCS 1 #define SENTINEL_MIN_LINK_RECONNECT_PERIOD 15000 #define SENTINEL_DEFAULT_FAILOVER_TIMEOUT (60*3*1000) #define SENTINEL_MAX_PENDING_COMMANDS 100 #define SENTINEL_ELECTION_TIMEOUT 10000 #define SENTINEL_MAX_DESYNC 1000 #define SENTINEL_DEFAULT_DENY_SCRIPTS_RECONFIG 1 #define SENTINEL_DEFAULT_RESOLVE_HOSTNAMES 0 #define SENTINEL_DEFAULT_ANNOUNCE_HOSTNAMES 0 /* Failover machine different states. */ #define SENTINEL_FAILOVER_STATE_NONE 0 /* No failover in progress. */ #define SENTINEL_FAILOVER_STATE_WAIT_START 1 /* Wait for failover_start_time*/ #define SENTINEL_FAILOVER_STATE_SELECT_SLAVE 2 /* Select slave to promote */ #define SENTINEL_FAILOVER_STATE_SEND_SLAVEOF_NOONE 3 /* Slave -> Master */ #define SENTINEL_FAILOVER_STATE_WAIT_PROMOTION 4 /* Wait slave to change role */ #define SENTINEL_FAILOVER_STATE_RECONF_SLAVES 5 /* SLAVEOF newmaster */ #define SENTINEL_FAILOVER_STATE_UPDATE_CONFIG 6 /* Monitor promoted slave. */ #define SENTINEL_MASTER_LINK_STATUS_UP 0 #define SENTINEL_MASTER_LINK_STATUS_DOWN 1 /* Generic flags that can be used with different functions. * They use higher bits to avoid colliding with the function specific * flags. */ #define SENTINEL_NO_FLAGS 0 #define SENTINEL_GENERATE_EVENT (1<<16) #define SENTINEL_LEADER (1<<17) #define SENTINEL_OBSERVER (1<<18) /* Script execution flags and limits. */ #define SENTINEL_SCRIPT_NONE 0 #define SENTINEL_SCRIPT_RUNNING 1 #define SENTINEL_SCRIPT_MAX_QUEUE 256 #define SENTINEL_SCRIPT_MAX_RUNNING 16 #define SENTINEL_SCRIPT_MAX_RUNTIME 60000 /* 60 seconds max exec time. */ #define SENTINEL_SCRIPT_MAX_RETRY 10 #define SENTINEL_SCRIPT_RETRY_DELAY 30000 /* 30 seconds between retries. */ /* SENTINEL SIMULATE-FAILURE command flags. */ #define SENTINEL_SIMFAILURE_NONE 0 #define SENTINEL_SIMFAILURE_CRASH_AFTER_ELECTION (1<<0) #define SENTINEL_SIMFAILURE_CRASH_AFTER_PROMOTION (1<<1) /* The link to a sentinelRedisInstance. When we have the same set of Sentinels * monitoring many masters, we have different instances representing the * same Sentinels, one per master, and we need to share the hiredis connections * among them. Otherwise if 5 Sentinels are monitoring 100 masters we create * 500 outgoing connections instead of 5. * * So this structure represents a reference counted link in terms of the two * hiredis connections for commands and Pub/Sub, and the fields needed for * failure detection, since the ping/pong time are now local to the link: if * the link is available, the instance is available. This way we don't just * have 5 connections instead of 500, we also send 5 pings instead of 500. * * Links are shared only for Sentinels: master and slave instances have * a link with refcount = 1, always. */ typedef struct instanceLink { int refcount; /* Number of sentinelRedisInstance owners. */ int disconnected; /* Non-zero if we need to reconnect cc or pc. */ int pending_commands; /* Number of commands sent waiting for a reply. */ redisAsyncContext *cc; /* Hiredis context for commands. */ redisAsyncContext *pc; /* Hiredis context for Pub / Sub. */ mstime_t cc_conn_time; /* cc connection time. */ mstime_t pc_conn_time; /* pc connection time. */ mstime_t pc_last_activity; /* Last time we received any message. */ mstime_t last_avail_time; /* Last time the instance replied to ping with a reply we consider valid. */ mstime_t act_ping_time; /* Time at which the last pending ping (no pong received after it) was sent. This field is set to 0 when a pong is received, and set again to the current time if the value is 0 and a new ping is sent. */ mstime_t last_ping_time; /* Time at which we sent the last ping. This is only used to avoid sending too many pings during failure. Idle time is computed using the act_ping_time field. */ mstime_t last_pong_time; /* Last time the instance replied to ping, whatever the reply was. That's used to check if the link is idle and must be reconnected. */ mstime_t last_reconn_time; /* Last reconnection attempt performed when the link was down. */ } instanceLink; typedef struct sentinelRedisInstance { int flags; /* See SRI_... defines */ char *name; /* Master name from the point of view of this sentinel. */ char *runid; /* Run ID of this instance, or unique ID if is a Sentinel.*/ uint64_t config_epoch; /* Configuration epoch. */ sentinelAddr *addr; /* Master host. */ instanceLink *link; /* Link to the instance, may be shared for Sentinels. */ mstime_t last_pub_time; /* Last time we sent hello via Pub/Sub. */ mstime_t last_hello_time; /* Only used if SRI_SENTINEL is set. Last time we received a hello from this Sentinel via Pub/Sub. */ mstime_t last_master_down_reply_time; /* Time of last reply to SENTINEL is-master-down command. */ mstime_t s_down_since_time; /* Subjectively down since time. */ mstime_t o_down_since_time; /* Objectively down since time. */ mstime_t down_after_period; /* Consider it down after that period. */ mstime_t info_refresh; /* Time at which we received INFO output from it. */ dict *renamed_commands; /* Commands renamed in this instance: Sentinel will use the alternative commands mapped on this table to send things like SLAVEOF, CONFING, INFO, ... */ /* Role and the first time we observed it. * This is useful in order to delay replacing what the instance reports * with our own configuration. We need to always wait some time in order * to give a chance to the leader to report the new configuration before * we do silly things. */ int role_reported; mstime_t role_reported_time; mstime_t slave_conf_change_time; /* Last time slave master addr changed. */ /* Master specific. */ dict *sentinels; /* Other sentinels monitoring the same master. */ dict *slaves; /* Slaves for this master instance. */ unsigned int quorum;/* Number of sentinels that need to agree on failure. */ int parallel_syncs; /* How many slaves to reconfigure at same time. */ char *auth_pass; /* Password to use for AUTH against master & replica. */ char *auth_user; /* Username for ACLs AUTH against master & replica. */ /* Slave specific. */ mstime_t master_link_down_time; /* Slave replication link down time. */ int slave_priority; /* Slave priority according to its INFO output. */ int replica_announced; /* Replica announcing according to its INFO output. */ mstime_t slave_reconf_sent_time; /* Time at which we sent SLAVE OF */ struct sentinelRedisInstance *master; /* Master instance if it's slave. */ char *slave_master_host; /* Master host as reported by INFO */ int slave_master_port; /* Master port as reported by INFO */ int slave_master_link_status; /* Master link status as reported by INFO */ unsigned long long slave_repl_offset; /* Slave replication offset. */ /* Failover */ char *leader; /* If this is a master instance, this is the runid of the Sentinel that should perform the failover. If this is a Sentinel, this is the runid of the Sentinel that this Sentinel voted as leader. */ uint64_t leader_epoch; /* Epoch of the 'leader' field. */ uint64_t failover_epoch; /* Epoch of the currently started failover. */ int failover_state; /* See SENTINEL_FAILOVER_STATE_* defines. */ mstime_t failover_state_change_time; mstime_t failover_start_time; /* Last failover attempt start time. */ mstime_t failover_timeout; /* Max time to refresh failover state. */ mstime_t failover_delay_logged; /* For what failover_start_time value we logged the failover delay. */ struct sentinelRedisInstance *promoted_slave; /* Promoted slave instance. */ /* Scripts executed to notify admin or reconfigure clients: when they * are set to NULL no script is executed. */ char *notification_script; char *client_reconfig_script; sds info; /* cached INFO output */ } sentinelRedisInstance; /* Main state. */ struct sentinelState { char myid[CONFIG_RUN_ID_SIZE+1]; /* This sentinel ID. */ uint64_t current_epoch; /* Current epoch. */ dict *masters; /* Dictionary of master sentinelRedisInstances. Key is the instance name, value is the sentinelRedisInstance structure pointer. */ int tilt; /* Are we in TILT mode? */ int running_scripts; /* Number of scripts in execution right now. */ mstime_t tilt_start_time; /* When TITL started. */ mstime_t previous_time; /* Last time we ran the time handler. */ list *scripts_queue; /* Queue of user scripts to execute. */ char *announce_ip; /* IP addr that is gossiped to other sentinels if not NULL. */ int announce_port; /* Port that is gossiped to other sentinels if non zero. */ unsigned long simfailure_flags; /* Failures simulation. */ int deny_scripts_reconfig; /* Allow SENTINEL SET ... to change script paths at runtime? */ char *sentinel_auth_pass; /* Password to use for AUTH against other sentinel */ char *sentinel_auth_user; /* Username for ACLs AUTH against other sentinel. */ int resolve_hostnames; /* Support use of hostnames, assuming DNS is well configured. */ int announce_hostnames; /* Announce hostnames instead of IPs when we have them. */ } sentinel; /* A script execution job. */ typedef struct sentinelScriptJob { int flags; /* Script job flags: SENTINEL_SCRIPT_* */ int retry_num; /* Number of times we tried to execute it. */ char **argv; /* Arguments to call the script. */ mstime_t start_time; /* Script execution time if the script is running, otherwise 0 if we are allowed to retry the execution at any time. If the script is not running and it's not 0, it means: do not run before the specified time. */ pid_t pid; /* Script execution pid. */ } sentinelScriptJob; /* ======================= hiredis ae.c adapters ============================= * Note: this implementation is taken from hiredis/adapters/ae.h, however * we have our modified copy for Sentinel in order to use our allocator * and to have full control over how the adapter works. */ typedef struct redisAeEvents { redisAsyncContext *context; aeEventLoop *loop; int fd; int reading, writing; } redisAeEvents; static void redisAeReadEvent(aeEventLoop *el, int fd, void *privdata, int mask) { ((void)el); ((void)fd); ((void)mask); redisAeEvents *e = (redisAeEvents*)privdata; redisAsyncHandleRead(e->context); } static void redisAeWriteEvent(aeEventLoop *el, int fd, void *privdata, int mask) { ((void)el); ((void)fd); ((void)mask); redisAeEvents *e = (redisAeEvents*)privdata; redisAsyncHandleWrite(e->context); } static void redisAeAddRead(void *privdata) { redisAeEvents *e = (redisAeEvents*)privdata; aeEventLoop *loop = e->loop; if (!e->reading) { e->reading = 1; aeCreateFileEvent(loop,e->fd,AE_READABLE,redisAeReadEvent,e); } } static void redisAeDelRead(void *privdata) { redisAeEvents *e = (redisAeEvents*)privdata; aeEventLoop *loop = e->loop; if (e->reading) { e->reading = 0; aeDeleteFileEvent(loop,e->fd,AE_READABLE); } } static void redisAeAddWrite(void *privdata) { redisAeEvents *e = (redisAeEvents*)privdata; aeEventLoop *loop = e->loop; if (!e->writing) { e->writing = 1; aeCreateFileEvent(loop,e->fd,AE_WRITABLE,redisAeWriteEvent,e); } } static void redisAeDelWrite(void *privdata) { redisAeEvents *e = (redisAeEvents*)privdata; aeEventLoop *loop = e->loop; if (e->writing) { e->writing = 0; aeDeleteFileEvent(loop,e->fd,AE_WRITABLE); } } static void redisAeCleanup(void *privdata) { redisAeEvents *e = (redisAeEvents*)privdata; redisAeDelRead(privdata); redisAeDelWrite(privdata); zfree(e); } static int redisAeAttach(aeEventLoop *loop, redisAsyncContext *ac) { redisContext *c = &(ac->c); redisAeEvents *e; /* Nothing should be attached when something is already attached */ if (ac->ev.data != NULL) return C_ERR; /* Create container for context and r/w events */ e = (redisAeEvents*)zmalloc(sizeof(*e)); e->context = ac; e->loop = loop; e->fd = c->fd; e->reading = e->writing = 0; /* Register functions to start/stop listening for events */ ac->ev.addRead = redisAeAddRead; ac->ev.delRead = redisAeDelRead; ac->ev.addWrite = redisAeAddWrite; ac->ev.delWrite = redisAeDelWrite; ac->ev.cleanup = redisAeCleanup; ac->ev.data = e; return C_OK; } /* ============================= Prototypes ================================= */ void sentinelLinkEstablishedCallback(const redisAsyncContext *c, int status); void sentinelDisconnectCallback(const redisAsyncContext *c, int status); void sentinelReceiveHelloMessages(redisAsyncContext *c, void *reply, void *privdata); sentinelRedisInstance *sentinelGetMasterByName(char *name); char *sentinelGetSubjectiveLeader(sentinelRedisInstance *master); char *sentinelGetObjectiveLeader(sentinelRedisInstance *master); int yesnotoi(char *s); void instanceLinkConnectionError(const redisAsyncContext *c); const char *sentinelRedisInstanceTypeStr(sentinelRedisInstance *ri); void sentinelAbortFailover(sentinelRedisInstance *ri); void sentinelEvent(int level, char *type, sentinelRedisInstance *ri, const char *fmt, ...); sentinelRedisInstance *sentinelSelectSlave(sentinelRedisInstance *master); void sentinelScheduleScriptExecution(char *path, ...); void sentinelStartFailover(sentinelRedisInstance *master); void sentinelDiscardReplyCallback(redisAsyncContext *c, void *reply, void *privdata); int sentinelSendSlaveOf(sentinelRedisInstance *ri, const sentinelAddr *addr); char *sentinelVoteLeader(sentinelRedisInstance *master, uint64_t req_epoch, char *req_runid, uint64_t *leader_epoch); void sentinelFlushConfig(void); void sentinelGenerateInitialMonitorEvents(void); int sentinelSendPing(sentinelRedisInstance *ri); int sentinelForceHelloUpdateForMaster(sentinelRedisInstance *master); sentinelRedisInstance *getSentinelRedisInstanceByAddrAndRunID(dict *instances, char *ip, int port, char *runid); void sentinelSimFailureCrash(void); /* ========================= Dictionary types =============================== */ uint64_t dictSdsHash(const void *key); uint64_t dictSdsCaseHash(const void *key); int dictSdsKeyCompare(void *privdata, const void *key1, const void *key2); int dictSdsKeyCaseCompare(void *privdata, const void *key1, const void *key2); void releaseSentinelRedisInstance(sentinelRedisInstance *ri); void dictInstancesValDestructor (void *privdata, void *obj) { UNUSED(privdata); releaseSentinelRedisInstance(obj); } /* Instance name (sds) -> instance (sentinelRedisInstance pointer) * * also used for: sentinelRedisInstance->sentinels dictionary that maps * sentinels ip:port to last seen time in Pub/Sub hello message. */ dictType instancesDictType = { dictSdsHash, /* hash function */ NULL, /* key dup */ NULL, /* val dup */ dictSdsKeyCompare, /* key compare */ NULL, /* key destructor */ dictInstancesValDestructor,/* val destructor */ NULL /* allow to expand */ }; /* Instance runid (sds) -> votes (long casted to void*) * * This is useful into sentinelGetObjectiveLeader() function in order to * count the votes and understand who is the leader. */ dictType leaderVotesDictType = { dictSdsHash, /* hash function */ NULL, /* key dup */ NULL, /* val dup */ dictSdsKeyCompare, /* key compare */ NULL, /* key destructor */ NULL, /* val destructor */ NULL /* allow to expand */ }; /* Instance renamed commands table. */ dictType renamedCommandsDictType = { dictSdsCaseHash, /* hash function */ NULL, /* key dup */ NULL, /* val dup */ dictSdsKeyCaseCompare, /* key compare */ dictSdsDestructor, /* key destructor */ dictSdsDestructor, /* val destructor */ NULL /* allow to expand */ }; /* =========================== Initialization =============================== */ void sentinelCommand(client *c); void sentinelInfoCommand(client *c); void sentinelSetCommand(client *c); void sentinelPublishCommand(client *c); void sentinelRoleCommand(client *c); void sentinelConfigGetCommand(client *c); void sentinelConfigSetCommand(client *c); struct redisCommand sentinelcmds[] = { {"ping",pingCommand,1,"fast @connection",0,NULL,0,0,0,0,0}, {"sentinel",sentinelCommand,-2,"admin",0,NULL,0,0,0,0,0}, {"subscribe",subscribeCommand,-2,"pub-sub",0,NULL,0,0,0,0,0}, {"unsubscribe",unsubscribeCommand,-1,"pub-sub",0,NULL,0,0,0,0,0}, {"psubscribe",psubscribeCommand,-2,"pub-sub",0,NULL,0,0,0,0,0}, {"punsubscribe",punsubscribeCommand,-1,"pub-sub",0,NULL,0,0,0,0,0}, {"publish",sentinelPublishCommand,3,"pub-sub fast",0,NULL,0,0,0,0,0}, {"info",sentinelInfoCommand,-1,"random @dangerous",0,NULL,0,0,0,0,0}, {"role",sentinelRoleCommand,1,"fast read-only @dangerous",0,NULL,0,0,0,0,0}, {"client",clientCommand,-2,"admin random @connection",0,NULL,0,0,0,0,0}, {"shutdown",shutdownCommand,-1,"admin",0,NULL,0,0,0,0,0}, {"auth",authCommand,-2,"no-auth fast @connection",0,NULL,0,0,0,0,0}, {"hello",helloCommand,-1,"no-auth fast @connection",0,NULL,0,0,0,0,0}, {"acl",aclCommand,-2,"admin",0,NULL,0,0,0,0,0,0}, {"command",commandCommand,-1, "random @connection", 0,NULL,0,0,0,0,0,0} }; /* this array is used for sentinel config lookup, which need to be loaded * before monitoring masters config to avoid dependency issues */ const char *preMonitorCfgName[] = { "announce-ip", "announce-port", "deny-scripts-reconfig", "sentinel-user", "sentinel-pass", "current-epoch", "myid", "resolve-hostnames", "announce-hostnames" }; /* This function overwrites a few normal Redis config default with Sentinel * specific defaults. */ void initSentinelConfig(void) { server.port = REDIS_SENTINEL_PORT; server.protected_mode = 0; /* Sentinel must be exposed. */ } void freeSentinelLoadQueueEntry(void *item); /* Perform the Sentinel mode initialization. */ void initSentinel(void) { unsigned int j; /* Remove usual Redis commands from the command table, then just add * the SENTINEL command. */ dictEmpty(server.commands,NULL); dictEmpty(server.orig_commands,NULL); ACLClearCommandID(); for (j = 0; j < sizeof(sentinelcmds)/sizeof(sentinelcmds[0]); j++) { int retval; struct redisCommand *cmd = sentinelcmds+j; cmd->id = ACLGetCommandID(cmd->name); /* Assign the ID used for ACL. */ retval = dictAdd(server.commands, sdsnew(cmd->name), cmd); serverAssert(retval == DICT_OK); retval = dictAdd(server.orig_commands, sdsnew(cmd->name), cmd); serverAssert(retval == DICT_OK); /* Translate the command string flags description into an actual * set of flags. */ if (populateCommandTableParseFlags(cmd,cmd->sflags) == C_ERR) serverPanic("Unsupported command flag"); } /* Initialize various data structures. */ sentinel.current_epoch = 0; sentinel.masters = dictCreate(&instancesDictType,NULL); sentinel.tilt = 0; sentinel.tilt_start_time = 0; sentinel.previous_time = mstime(); sentinel.running_scripts = 0; sentinel.scripts_queue = listCreate(); sentinel.announce_ip = NULL; sentinel.announce_port = 0; sentinel.simfailure_flags = SENTINEL_SIMFAILURE_NONE; sentinel.deny_scripts_reconfig = SENTINEL_DEFAULT_DENY_SCRIPTS_RECONFIG; sentinel.sentinel_auth_pass = NULL; sentinel.sentinel_auth_user = NULL; sentinel.resolve_hostnames = SENTINEL_DEFAULT_RESOLVE_HOSTNAMES; sentinel.announce_hostnames = SENTINEL_DEFAULT_ANNOUNCE_HOSTNAMES; memset(sentinel.myid,0,sizeof(sentinel.myid)); server.sentinel_config = NULL; } /* This function is for checking whether sentinel config file has been set, * also checking whether we have write permissions. */ void sentinelCheckConfigFile(void) { if (server.configfile == NULL) { serverLog(LL_WARNING, "Sentinel needs config file on disk to save state. Exiting..."); exit(1); } else if (access(server.configfile,W_OK) == -1) { serverLog(LL_WARNING, "Sentinel config file %s is not writable: %s. Exiting...", server.configfile,strerror(errno)); exit(1); } } /* This function gets called when the server is in Sentinel mode, started, * loaded the configuration, and is ready for normal operations. */ void sentinelIsRunning(void) { int j; /* If this Sentinel has yet no ID set in the configuration file, we * pick a random one and persist the config on disk. From now on this * will be this Sentinel ID across restarts. */ for (j = 0; j < CONFIG_RUN_ID_SIZE; j++) if (sentinel.myid[j] != 0) break; if (j == CONFIG_RUN_ID_SIZE) { /* Pick ID and persist the config. */ getRandomHexChars(sentinel.myid,CONFIG_RUN_ID_SIZE); sentinelFlushConfig(); } /* Log its ID to make debugging of issues simpler. */ serverLog(LL_WARNING,"Sentinel ID is %s", sentinel.myid); /* We want to generate a +monitor event for every configured master * at startup. */ sentinelGenerateInitialMonitorEvents(); } /* ============================== sentinelAddr ============================== */ /* Create a sentinelAddr object and return it on success. * On error NULL is returned and errno is set to: * ENOENT: Can't resolve the hostname. * EINVAL: Invalid port number. */ sentinelAddr *createSentinelAddr(char *hostname, int port) { char ip[NET_IP_STR_LEN]; sentinelAddr *sa; if (port < 0 || port > 65535) { errno = EINVAL; return NULL; } if (anetResolve(NULL,hostname,ip,sizeof(ip), sentinel.resolve_hostnames ? ANET_NONE : ANET_IP_ONLY) == ANET_ERR) { errno = ENOENT; return NULL; } sa = zmalloc(sizeof(*sa)); sa->hostname = sdsnew(hostname); sa->ip = sdsnew(ip); sa->port = port; return sa; } /* Return a duplicate of the source address. */ sentinelAddr *dupSentinelAddr(sentinelAddr *src) { sentinelAddr *sa; sa = zmalloc(sizeof(*sa)); sa->hostname = sdsnew(src->hostname); sa->ip = sdsnew(src->ip); sa->port = src->port; return sa; } /* Free a Sentinel address. Can't fail. */ void releaseSentinelAddr(sentinelAddr *sa) { sdsfree(sa->hostname); sdsfree(sa->ip); zfree(sa); } /* Return non-zero if two addresses are equal. */ int sentinelAddrIsEqual(sentinelAddr *a, sentinelAddr *b) { return a->port == b->port && !strcasecmp(a->ip,b->ip); } /* Return non-zero if a hostname matches an address. */ int sentinelAddrEqualsHostname(sentinelAddr *a, char *hostname) { char ip[NET_IP_STR_LEN]; /* We always resolve the hostname and compare it to the address */ if (anetResolve(NULL, hostname, ip, sizeof(ip), sentinel.resolve_hostnames ? ANET_NONE : ANET_IP_ONLY) == ANET_ERR) return 0; return !strcasecmp(a->ip, ip); } const char *announceSentinelAddr(const sentinelAddr *a) { return sentinel.announce_hostnames ? a->hostname : a->ip; } /* Return an allocated sds with hostname/address:port. IPv6 * addresses are bracketed the same way anetFormatAddr() does. */ sds announceSentinelAddrAndPort(const sentinelAddr *a) { const char *addr = announceSentinelAddr(a); if (strchr(addr, ':') != NULL) return sdscatprintf(sdsempty(), "[%s]:%d", addr, a->port); else return sdscatprintf(sdsempty(), "%s:%d", addr, a->port); } /* =========================== Events notification ========================== */ /* Send an event to log, pub/sub, user notification script. * * 'level' is the log level for logging. Only LL_WARNING events will trigger * the execution of the user notification script. * * 'type' is the message type, also used as a pub/sub channel name. * * 'ri', is the redis instance target of this event if applicable, and is * used to obtain the path of the notification script to execute. * * The remaining arguments are printf-alike. * If the format specifier starts with the two characters "%@" then ri is * not NULL, and the message is prefixed with an instance identifier in the * following format: * * * * If the instance type is not master, than the additional string is * added to specify the originating master: * * @ * * Any other specifier after "%@" is processed by printf itself. */ void sentinelEvent(int level, char *type, sentinelRedisInstance *ri, const char *fmt, ...) { va_list ap; char msg[LOG_MAX_LEN]; robj *channel, *payload; /* Handle %@ */ if (fmt[0] == '%' && fmt[1] == '@') { sentinelRedisInstance *master = (ri->flags & SRI_MASTER) ? NULL : ri->master; if (master) { snprintf(msg, sizeof(msg), "%s %s %s %d @ %s %s %d", sentinelRedisInstanceTypeStr(ri), ri->name, announceSentinelAddr(ri->addr), ri->addr->port, master->name, announceSentinelAddr(master->addr), master->addr->port); } else { snprintf(msg, sizeof(msg), "%s %s %s %d", sentinelRedisInstanceTypeStr(ri), ri->name, announceSentinelAddr(ri->addr), ri->addr->port); } fmt += 2; } else { msg[0] = '\0'; } /* Use vsprintf for the rest of the formatting if any. */ if (fmt[0] != '\0') { va_start(ap, fmt); vsnprintf(msg+strlen(msg), sizeof(msg)-strlen(msg), fmt, ap); va_end(ap); } /* Log the message if the log level allows it to be logged. */ if (level >= server.verbosity) serverLog(level,"%s %s",type,msg); /* Publish the message via Pub/Sub if it's not a debugging one. */ if (level != LL_DEBUG) { channel = createStringObject(type,strlen(type)); payload = createStringObject(msg,strlen(msg)); pubsubPublishMessage(channel,payload); decrRefCount(channel); decrRefCount(payload); } /* Call the notification script if applicable. */ if (level == LL_WARNING && ri != NULL) { sentinelRedisInstance *master = (ri->flags & SRI_MASTER) ? ri : ri->master; if (master && master->notification_script) { sentinelScheduleScriptExecution(master->notification_script, type,msg,NULL); } } } /* This function is called only at startup and is used to generate a * +monitor event for every configured master. The same events are also * generated when a master to monitor is added at runtime via the * SENTINEL MONITOR command. */ void sentinelGenerateInitialMonitorEvents(void) { dictIterator *di; dictEntry *de; di = dictGetIterator(sentinel.masters); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); sentinelEvent(LL_WARNING,"+monitor",ri,"%@ quorum %d",ri->quorum); } dictReleaseIterator(di); } /* ============================ script execution ============================ */ /* Release a script job structure and all the associated data. */ void sentinelReleaseScriptJob(sentinelScriptJob *sj) { int j = 0; while(sj->argv[j]) sdsfree(sj->argv[j++]); zfree(sj->argv); zfree(sj); } #define SENTINEL_SCRIPT_MAX_ARGS 16 void sentinelScheduleScriptExecution(char *path, ...) { va_list ap; char *argv[SENTINEL_SCRIPT_MAX_ARGS+1]; int argc = 1; sentinelScriptJob *sj; va_start(ap, path); while(argc < SENTINEL_SCRIPT_MAX_ARGS) { argv[argc] = va_arg(ap,char*); if (!argv[argc]) break; argv[argc] = sdsnew(argv[argc]); /* Copy the string. */ argc++; } va_end(ap); argv[0] = sdsnew(path); sj = zmalloc(sizeof(*sj)); sj->flags = SENTINEL_SCRIPT_NONE; sj->retry_num = 0; sj->argv = zmalloc(sizeof(char*)*(argc+1)); sj->start_time = 0; sj->pid = 0; memcpy(sj->argv,argv,sizeof(char*)*(argc+1)); listAddNodeTail(sentinel.scripts_queue,sj); /* Remove the oldest non running script if we already hit the limit. */ if (listLength(sentinel.scripts_queue) > SENTINEL_SCRIPT_MAX_QUEUE) { listNode *ln; listIter li; listRewind(sentinel.scripts_queue,&li); while ((ln = listNext(&li)) != NULL) { sj = ln->value; if (sj->flags & SENTINEL_SCRIPT_RUNNING) continue; /* The first node is the oldest as we add on tail. */ listDelNode(sentinel.scripts_queue,ln); sentinelReleaseScriptJob(sj); break; } serverAssert(listLength(sentinel.scripts_queue) <= SENTINEL_SCRIPT_MAX_QUEUE); } } /* Lookup a script in the scripts queue via pid, and returns the list node * (so that we can easily remove it from the queue if needed). */ listNode *sentinelGetScriptListNodeByPid(pid_t pid) { listNode *ln; listIter li; listRewind(sentinel.scripts_queue,&li); while ((ln = listNext(&li)) != NULL) { sentinelScriptJob *sj = ln->value; if ((sj->flags & SENTINEL_SCRIPT_RUNNING) && sj->pid == pid) return ln; } return NULL; } /* Run pending scripts if we are not already at max number of running * scripts. */ void sentinelRunPendingScripts(void) { listNode *ln; listIter li; mstime_t now = mstime(); /* Find jobs that are not running and run them, from the top to the * tail of the queue, so we run older jobs first. */ listRewind(sentinel.scripts_queue,&li); while (sentinel.running_scripts < SENTINEL_SCRIPT_MAX_RUNNING && (ln = listNext(&li)) != NULL) { sentinelScriptJob *sj = ln->value; pid_t pid; /* Skip if already running. */ if (sj->flags & SENTINEL_SCRIPT_RUNNING) continue; /* Skip if it's a retry, but not enough time has elapsed. */ if (sj->start_time && sj->start_time > now) continue; sj->flags |= SENTINEL_SCRIPT_RUNNING; sj->start_time = mstime(); sj->retry_num++; pid = fork(); if (pid == -1) { /* Parent (fork error). * We report fork errors as signal 99, in order to unify the * reporting with other kind of errors. */ sentinelEvent(LL_WARNING,"-script-error",NULL, "%s %d %d", sj->argv[0], 99, 0); sj->flags &= ~SENTINEL_SCRIPT_RUNNING; sj->pid = 0; } else if (pid == 0) { /* Child */ tlsCleanup(); execve(sj->argv[0],sj->argv,environ); /* If we are here an error occurred. */ _exit(2); /* Don't retry execution. */ } else { sentinel.running_scripts++; sj->pid = pid; sentinelEvent(LL_DEBUG,"+script-child",NULL,"%ld",(long)pid); } } } /* How much to delay the execution of a script that we need to retry after * an error? * * We double the retry delay for every further retry we do. So for instance * if RETRY_DELAY is set to 30 seconds and the max number of retries is 10 * starting from the second attempt to execute the script the delays are: * 30 sec, 60 sec, 2 min, 4 min, 8 min, 16 min, 32 min, 64 min, 128 min. */ mstime_t sentinelScriptRetryDelay(int retry_num) { mstime_t delay = SENTINEL_SCRIPT_RETRY_DELAY; while (retry_num-- > 1) delay *= 2; return delay; } /* Check for scripts that terminated, and remove them from the queue if the * script terminated successfully. If instead the script was terminated by * a signal, or returned exit code "1", it is scheduled to run again if * the max number of retries did not already elapsed. */ void sentinelCollectTerminatedScripts(void) { int statloc; pid_t pid; while ((pid = waitpid(-1, &statloc, WNOHANG)) > 0) { int exitcode = WEXITSTATUS(statloc); int bysignal = 0; listNode *ln; sentinelScriptJob *sj; if (WIFSIGNALED(statloc)) bysignal = WTERMSIG(statloc); sentinelEvent(LL_DEBUG,"-script-child",NULL,"%ld %d %d", (long)pid, exitcode, bysignal); ln = sentinelGetScriptListNodeByPid(pid); if (ln == NULL) { serverLog(LL_WARNING,"waitpid() returned a pid (%ld) we can't find in our scripts execution queue!", (long)pid); continue; } sj = ln->value; /* If the script was terminated by a signal or returns an * exit code of "1" (that means: please retry), we reschedule it * if the max number of retries is not already reached. */ if ((bysignal || exitcode == 1) && sj->retry_num != SENTINEL_SCRIPT_MAX_RETRY) { sj->flags &= ~SENTINEL_SCRIPT_RUNNING; sj->pid = 0; sj->start_time = mstime() + sentinelScriptRetryDelay(sj->retry_num); } else { /* Otherwise let's remove the script, but log the event if the * execution did not terminated in the best of the ways. */ if (bysignal || exitcode != 0) { sentinelEvent(LL_WARNING,"-script-error",NULL, "%s %d %d", sj->argv[0], bysignal, exitcode); } listDelNode(sentinel.scripts_queue,ln); sentinelReleaseScriptJob(sj); } sentinel.running_scripts--; } } /* Kill scripts in timeout, they'll be collected by the * sentinelCollectTerminatedScripts() function. */ void sentinelKillTimedoutScripts(void) { listNode *ln; listIter li; mstime_t now = mstime(); listRewind(sentinel.scripts_queue,&li); while ((ln = listNext(&li)) != NULL) { sentinelScriptJob *sj = ln->value; if (sj->flags & SENTINEL_SCRIPT_RUNNING && (now - sj->start_time) > SENTINEL_SCRIPT_MAX_RUNTIME) { sentinelEvent(LL_WARNING,"-script-timeout",NULL,"%s %ld", sj->argv[0], (long)sj->pid); kill(sj->pid,SIGKILL); } } } /* Implements SENTINEL PENDING-SCRIPTS command. */ void sentinelPendingScriptsCommand(client *c) { listNode *ln; listIter li; addReplyArrayLen(c,listLength(sentinel.scripts_queue)); listRewind(sentinel.scripts_queue,&li); while ((ln = listNext(&li)) != NULL) { sentinelScriptJob *sj = ln->value; int j = 0; addReplyMapLen(c,5); addReplyBulkCString(c,"argv"); while (sj->argv[j]) j++; addReplyArrayLen(c,j); j = 0; while (sj->argv[j]) addReplyBulkCString(c,sj->argv[j++]); addReplyBulkCString(c,"flags"); addReplyBulkCString(c, (sj->flags & SENTINEL_SCRIPT_RUNNING) ? "running" : "scheduled"); addReplyBulkCString(c,"pid"); addReplyBulkLongLong(c,sj->pid); if (sj->flags & SENTINEL_SCRIPT_RUNNING) { addReplyBulkCString(c,"run-time"); addReplyBulkLongLong(c,mstime() - sj->start_time); } else { mstime_t delay = sj->start_time ? (sj->start_time-mstime()) : 0; if (delay < 0) delay = 0; addReplyBulkCString(c,"run-delay"); addReplyBulkLongLong(c,delay); } addReplyBulkCString(c,"retry-num"); addReplyBulkLongLong(c,sj->retry_num); } } /* This function calls, if any, the client reconfiguration script with the * following parameters: * * * * It is called every time a failover is performed. * * is currently always "failover". * is either "leader" or "observer". * * from/to fields are respectively master -> promoted slave addresses for * "start" and "end". */ void sentinelCallClientReconfScript(sentinelRedisInstance *master, int role, char *state, sentinelAddr *from, sentinelAddr *to) { char fromport[32], toport[32]; if (master->client_reconfig_script == NULL) return; ll2string(fromport,sizeof(fromport),from->port); ll2string(toport,sizeof(toport),to->port); sentinelScheduleScriptExecution(master->client_reconfig_script, master->name, (role == SENTINEL_LEADER) ? "leader" : "observer", state, announceSentinelAddr(from), fromport, announceSentinelAddr(to), toport, NULL); } /* =============================== instanceLink ============================= */ /* Create a not yet connected link object. */ instanceLink *createInstanceLink(void) { instanceLink *link = zmalloc(sizeof(*link)); link->refcount = 1; link->disconnected = 1; link->pending_commands = 0; link->cc = NULL; link->pc = NULL; link->cc_conn_time = 0; link->pc_conn_time = 0; link->last_reconn_time = 0; link->pc_last_activity = 0; /* We set the act_ping_time to "now" even if we actually don't have yet * a connection with the node, nor we sent a ping. * This is useful to detect a timeout in case we'll not be able to connect * with the node at all. */ link->act_ping_time = mstime(); link->last_ping_time = 0; link->last_avail_time = mstime(); link->last_pong_time = mstime(); return link; } /* Disconnect a hiredis connection in the context of an instance link. */ void instanceLinkCloseConnection(instanceLink *link, redisAsyncContext *c) { if (c == NULL) return; if (link->cc == c) { link->cc = NULL; link->pending_commands = 0; } if (link->pc == c) link->pc = NULL; c->data = NULL; link->disconnected = 1; redisAsyncFree(c); } /* Decrement the refcount of a link object, if it drops to zero, actually * free it and return NULL. Otherwise don't do anything and return the pointer * to the object. * * If we are not going to free the link and ri is not NULL, we rebind all the * pending requests in link->cc (hiredis connection for commands) to a * callback that will just ignore them. This is useful to avoid processing * replies for an instance that no longer exists. */ instanceLink *releaseInstanceLink(instanceLink *link, sentinelRedisInstance *ri) { serverAssert(link->refcount > 0); link->refcount--; if (link->refcount != 0) { if (ri && ri->link->cc) { /* This instance may have pending callbacks in the hiredis async * context, having as 'privdata' the instance that we are going to * free. Let's rewrite the callback list, directly exploiting * hiredis internal data structures, in order to bind them with * a callback that will ignore the reply at all. */ redisCallback *cb; redisCallbackList *callbacks = &link->cc->replies; cb = callbacks->head; while(cb) { if (cb->privdata == ri) { cb->fn = sentinelDiscardReplyCallback; cb->privdata = NULL; /* Not strictly needed. */ } cb = cb->next; } } return link; /* Other active users. */ } instanceLinkCloseConnection(link,link->cc); instanceLinkCloseConnection(link,link->pc); zfree(link); return NULL; } /* This function will attempt to share the instance link we already have * for the same Sentinel in the context of a different master, with the * instance we are passing as argument. * * This way multiple Sentinel objects that refer all to the same physical * Sentinel instance but in the context of different masters will use * a single connection, will send a single PING per second for failure * detection and so forth. * * Return C_OK if a matching Sentinel was found in the context of a * different master and sharing was performed. Otherwise C_ERR * is returned. */ int sentinelTryConnectionSharing(sentinelRedisInstance *ri) { serverAssert(ri->flags & SRI_SENTINEL); dictIterator *di; dictEntry *de; if (ri->runid == NULL) return C_ERR; /* No way to identify it. */ if (ri->link->refcount > 1) return C_ERR; /* Already shared. */ di = dictGetIterator(sentinel.masters); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *master = dictGetVal(de), *match; /* We want to share with the same physical Sentinel referenced * in other masters, so skip our master. */ if (master == ri->master) continue; match = getSentinelRedisInstanceByAddrAndRunID(master->sentinels, NULL,0,ri->runid); if (match == NULL) continue; /* No match. */ if (match == ri) continue; /* Should never happen but... safer. */ /* We identified a matching Sentinel, great! Let's free our link * and use the one of the matching Sentinel. */ releaseInstanceLink(ri->link,NULL); ri->link = match->link; match->link->refcount++; dictReleaseIterator(di); return C_OK; } dictReleaseIterator(di); return C_ERR; } /* Drop all connections to other sentinels. Returns the number of connections * dropped.*/ int sentinelDropConnections(void) { dictIterator *di; dictEntry *de; int dropped = 0; di = dictGetIterator(sentinel.masters); while ((de = dictNext(di)) != NULL) { dictIterator *sdi; dictEntry *sde; sentinelRedisInstance *ri = dictGetVal(de); sdi = dictGetIterator(ri->sentinels); while ((sde = dictNext(sdi)) != NULL) { sentinelRedisInstance *si = dictGetVal(sde); if (!si->link->disconnected) { instanceLinkCloseConnection(si->link, si->link->pc); instanceLinkCloseConnection(si->link, si->link->cc); dropped++; } } dictReleaseIterator(sdi); } dictReleaseIterator(di); return dropped; } /* When we detect a Sentinel to switch address (reporting a different IP/port * pair in Hello messages), let's update all the matching Sentinels in the * context of other masters as well and disconnect the links, so that everybody * will be updated. * * Return the number of updated Sentinel addresses. */ int sentinelUpdateSentinelAddressInAllMasters(sentinelRedisInstance *ri) { serverAssert(ri->flags & SRI_SENTINEL); dictIterator *di; dictEntry *de; int reconfigured = 0; di = dictGetIterator(sentinel.masters); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *master = dictGetVal(de), *match; match = getSentinelRedisInstanceByAddrAndRunID(master->sentinels, NULL,0,ri->runid); /* If there is no match, this master does not know about this * Sentinel, try with the next one. */ if (match == NULL) continue; /* Disconnect the old links if connected. */ if (match->link->cc != NULL) instanceLinkCloseConnection(match->link,match->link->cc); if (match->link->pc != NULL) instanceLinkCloseConnection(match->link,match->link->pc); if (match == ri) continue; /* Address already updated for it. */ /* Update the address of the matching Sentinel by copying the address * of the Sentinel object that received the address update. */ releaseSentinelAddr(match->addr); match->addr = dupSentinelAddr(ri->addr); reconfigured++; } dictReleaseIterator(di); if (reconfigured) sentinelEvent(LL_NOTICE,"+sentinel-address-update", ri, "%@ %d additional matching instances", reconfigured); return reconfigured; } /* This function is called when a hiredis connection reported an error. * We set it to NULL and mark the link as disconnected so that it will be * reconnected again. * * Note: we don't free the hiredis context as hiredis will do it for us * for async connections. */ void instanceLinkConnectionError(const redisAsyncContext *c) { instanceLink *link = c->data; int pubsub; if (!link) return; pubsub = (link->pc == c); if (pubsub) link->pc = NULL; else link->cc = NULL; link->disconnected = 1; } /* Hiredis connection established / disconnected callbacks. We need them * just to cleanup our link state. */ void sentinelLinkEstablishedCallback(const redisAsyncContext *c, int status) { if (status != C_OK) instanceLinkConnectionError(c); } void sentinelDisconnectCallback(const redisAsyncContext *c, int status) { UNUSED(status); instanceLinkConnectionError(c); } /* ========================== sentinelRedisInstance ========================= */ /* Create a redis instance, the following fields must be populated by the * caller if needed: * runid: set to NULL but will be populated once INFO output is received. * info_refresh: is set to 0 to mean that we never received INFO so far. * * If SRI_MASTER is set into initial flags the instance is added to * sentinel.masters table. * * if SRI_SLAVE or SRI_SENTINEL is set then 'master' must be not NULL and the * instance is added into master->slaves or master->sentinels table. * * If the instance is a slave or sentinel, the name parameter is ignored and * is created automatically as hostname:port. * * The function fails if hostname can't be resolved or port is out of range. * When this happens NULL is returned and errno is set accordingly to the * createSentinelAddr() function. * * The function may also fail and return NULL with errno set to EBUSY if * a master with the same name, a slave with the same address, or a sentinel * with the same ID already exists. */ sentinelRedisInstance *createSentinelRedisInstance(char *name, int flags, char *hostname, int port, int quorum, sentinelRedisInstance *master) { sentinelRedisInstance *ri; sentinelAddr *addr; dict *table = NULL; sds sdsname; serverAssert(flags & (SRI_MASTER|SRI_SLAVE|SRI_SENTINEL)); serverAssert((flags & SRI_MASTER) || master != NULL); /* Check address validity. */ addr = createSentinelAddr(hostname,port); if (addr == NULL) return NULL; /* For slaves use ip/host:port as name. */ if (flags & SRI_SLAVE) sdsname = announceSentinelAddrAndPort(addr); else sdsname = sdsnew(name); /* Make sure the entry is not duplicated. This may happen when the same * name for a master is used multiple times inside the configuration or * if we try to add multiple times a slave or sentinel with same ip/port * to a master. */ if (flags & SRI_MASTER) table = sentinel.masters; else if (flags & SRI_SLAVE) table = master->slaves; else if (flags & SRI_SENTINEL) table = master->sentinels; if (dictFind(table,sdsname)) { releaseSentinelAddr(addr); sdsfree(sdsname); errno = EBUSY; return NULL; } /* Create the instance object. */ ri = zmalloc(sizeof(*ri)); /* Note that all the instances are started in the disconnected state, * the event loop will take care of connecting them. */ ri->flags = flags; ri->name = sdsname; ri->runid = NULL; ri->config_epoch = 0; ri->addr = addr; ri->link = createInstanceLink(); ri->last_pub_time = mstime(); ri->last_hello_time = mstime(); ri->last_master_down_reply_time = mstime(); ri->s_down_since_time = 0; ri->o_down_since_time = 0; ri->down_after_period = master ? master->down_after_period : SENTINEL_DEFAULT_DOWN_AFTER; ri->master_link_down_time = 0; ri->auth_pass = NULL; ri->auth_user = NULL; ri->slave_priority = SENTINEL_DEFAULT_SLAVE_PRIORITY; ri->replica_announced = 1; ri->slave_reconf_sent_time = 0; ri->slave_master_host = NULL; ri->slave_master_port = 0; ri->slave_master_link_status = SENTINEL_MASTER_LINK_STATUS_DOWN; ri->slave_repl_offset = 0; ri->sentinels = dictCreate(&instancesDictType,NULL); ri->quorum = quorum; ri->parallel_syncs = SENTINEL_DEFAULT_PARALLEL_SYNCS; ri->master = master; ri->slaves = dictCreate(&instancesDictType,NULL); ri->info_refresh = 0; ri->renamed_commands = dictCreate(&renamedCommandsDictType,NULL); /* Failover state. */ ri->leader = NULL; ri->leader_epoch = 0; ri->failover_epoch = 0; ri->failover_state = SENTINEL_FAILOVER_STATE_NONE; ri->failover_state_change_time = 0; ri->failover_start_time = 0; ri->failover_timeout = SENTINEL_DEFAULT_FAILOVER_TIMEOUT; ri->failover_delay_logged = 0; ri->promoted_slave = NULL; ri->notification_script = NULL; ri->client_reconfig_script = NULL; ri->info = NULL; /* Role */ ri->role_reported = ri->flags & (SRI_MASTER|SRI_SLAVE); ri->role_reported_time = mstime(); ri->slave_conf_change_time = mstime(); /* Add into the right table. */ dictAdd(table, ri->name, ri); return ri; } /* Release this instance and all its slaves, sentinels, hiredis connections. * This function does not take care of unlinking the instance from the main * masters table (if it is a master) or from its master sentinels/slaves table * if it is a slave or sentinel. */ void releaseSentinelRedisInstance(sentinelRedisInstance *ri) { /* Release all its slaves or sentinels if any. */ dictRelease(ri->sentinels); dictRelease(ri->slaves); /* Disconnect the instance. */ releaseInstanceLink(ri->link,ri); /* Free other resources. */ sdsfree(ri->name); sdsfree(ri->runid); sdsfree(ri->notification_script); sdsfree(ri->client_reconfig_script); sdsfree(ri->slave_master_host); sdsfree(ri->leader); sdsfree(ri->auth_pass); sdsfree(ri->auth_user); sdsfree(ri->info); releaseSentinelAddr(ri->addr); dictRelease(ri->renamed_commands); /* Clear state into the master if needed. */ if ((ri->flags & SRI_SLAVE) && (ri->flags & SRI_PROMOTED) && ri->master) ri->master->promoted_slave = NULL; zfree(ri); } /* Lookup a slave in a master Redis instance, by ip and port. */ sentinelRedisInstance *sentinelRedisInstanceLookupSlave( sentinelRedisInstance *ri, char *slave_addr, int port) { sds key; sentinelRedisInstance *slave; sentinelAddr *addr; serverAssert(ri->flags & SRI_MASTER); /* We need to handle a slave_addr that is potentially a hostname. * If that is the case, depending on configuration we either resolve * it and use the IP addres or fail. */ addr = createSentinelAddr(slave_addr, port); if (!addr) return NULL; key = announceSentinelAddrAndPort(addr); releaseSentinelAddr(addr); slave = dictFetchValue(ri->slaves,key); sdsfree(key); return slave; } /* Return the name of the type of the instance as a string. */ const char *sentinelRedisInstanceTypeStr(sentinelRedisInstance *ri) { if (ri->flags & SRI_MASTER) return "master"; else if (ri->flags & SRI_SLAVE) return "slave"; else if (ri->flags & SRI_SENTINEL) return "sentinel"; else return "unknown"; } /* This function remove the Sentinel with the specified ID from the * specified master. * * If "runid" is NULL the function returns ASAP. * * This function is useful because on Sentinels address switch, we want to * remove our old entry and add a new one for the same ID but with the new * address. * * The function returns 1 if the matching Sentinel was removed, otherwise * 0 if there was no Sentinel with this ID. */ int removeMatchingSentinelFromMaster(sentinelRedisInstance *master, char *runid) { dictIterator *di; dictEntry *de; int removed = 0; if (runid == NULL) return 0; di = dictGetSafeIterator(master->sentinels); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); if (ri->runid && strcmp(ri->runid,runid) == 0) { dictDelete(master->sentinels,ri->name); removed++; } } dictReleaseIterator(di); return removed; } /* Search an instance with the same runid, ip and port into a dictionary * of instances. Return NULL if not found, otherwise return the instance * pointer. * * runid or addr can be NULL. In such a case the search is performed only * by the non-NULL field. */ sentinelRedisInstance *getSentinelRedisInstanceByAddrAndRunID(dict *instances, char *addr, int port, char *runid) { dictIterator *di; dictEntry *de; sentinelRedisInstance *instance = NULL; sentinelAddr *ri_addr = NULL; serverAssert(addr || runid); /* User must pass at least one search param. */ if (addr != NULL) { /* Resolve addr, we use the IP as a key even if a hostname is used */ ri_addr = createSentinelAddr(addr, port); if (!ri_addr) return NULL; } di = dictGetIterator(instances); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); if (runid && !ri->runid) continue; if ((runid == NULL || strcmp(ri->runid, runid) == 0) && (addr == NULL || (strcmp(ri->addr->ip, ri_addr->ip) == 0 && ri->addr->port == port))) { instance = ri; break; } } dictReleaseIterator(di); if (ri_addr != NULL) releaseSentinelAddr(ri_addr); return instance; } /* Master lookup by name */ sentinelRedisInstance *sentinelGetMasterByName(char *name) { sentinelRedisInstance *ri; sds sdsname = sdsnew(name); ri = dictFetchValue(sentinel.masters,sdsname); sdsfree(sdsname); return ri; } /* Add the specified flags to all the instances in the specified dictionary. */ void sentinelAddFlagsToDictOfRedisInstances(dict *instances, int flags) { dictIterator *di; dictEntry *de; di = dictGetIterator(instances); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); ri->flags |= flags; } dictReleaseIterator(di); } /* Remove the specified flags to all the instances in the specified * dictionary. */ void sentinelDelFlagsToDictOfRedisInstances(dict *instances, int flags) { dictIterator *di; dictEntry *de; di = dictGetIterator(instances); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); ri->flags &= ~flags; } dictReleaseIterator(di); } /* Reset the state of a monitored master: * 1) Remove all slaves. * 2) Remove all sentinels. * 3) Remove most of the flags resulting from runtime operations. * 4) Reset timers to their default value. For example after a reset it will be * possible to failover again the same master ASAP, without waiting the * failover timeout delay. * 5) In the process of doing this undo the failover if in progress. * 6) Disconnect the connections with the master (will reconnect automatically). */ #define SENTINEL_RESET_NO_SENTINELS (1<<0) void sentinelResetMaster(sentinelRedisInstance *ri, int flags) { serverAssert(ri->flags & SRI_MASTER); dictRelease(ri->slaves); ri->slaves = dictCreate(&instancesDictType,NULL); if (!(flags & SENTINEL_RESET_NO_SENTINELS)) { dictRelease(ri->sentinels); ri->sentinels = dictCreate(&instancesDictType,NULL); } instanceLinkCloseConnection(ri->link,ri->link->cc); instanceLinkCloseConnection(ri->link,ri->link->pc); ri->flags &= SRI_MASTER; if (ri->leader) { sdsfree(ri->leader); ri->leader = NULL; } ri->failover_state = SENTINEL_FAILOVER_STATE_NONE; ri->failover_state_change_time = 0; ri->failover_start_time = 0; /* We can failover again ASAP. */ ri->promoted_slave = NULL; sdsfree(ri->runid); sdsfree(ri->slave_master_host); ri->runid = NULL; ri->slave_master_host = NULL; ri->link->act_ping_time = mstime(); ri->link->last_ping_time = 0; ri->link->last_avail_time = mstime(); ri->link->last_pong_time = mstime(); ri->role_reported_time = mstime(); ri->role_reported = SRI_MASTER; if (flags & SENTINEL_GENERATE_EVENT) sentinelEvent(LL_WARNING,"+reset-master",ri,"%@"); } /* Call sentinelResetMaster() on every master with a name matching the specified * pattern. */ int sentinelResetMastersByPattern(char *pattern, int flags) { dictIterator *di; dictEntry *de; int reset = 0; di = dictGetIterator(sentinel.masters); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); if (ri->name) { if (stringmatch(pattern,ri->name,0)) { sentinelResetMaster(ri,flags); reset++; } } } dictReleaseIterator(di); return reset; } /* Reset the specified master with sentinelResetMaster(), and also change * the ip:port address, but take the name of the instance unmodified. * * This is used to handle the +switch-master event. * * The function returns C_ERR if the address can't be resolved for some * reason. Otherwise C_OK is returned. */ int sentinelResetMasterAndChangeAddress(sentinelRedisInstance *master, char *hostname, int port) { sentinelAddr *oldaddr, *newaddr; sentinelAddr **slaves = NULL; int numslaves = 0, j; dictIterator *di; dictEntry *de; newaddr = createSentinelAddr(hostname,port); if (newaddr == NULL) return C_ERR; /* There can be only 0 or 1 slave that has the newaddr. * and It can add old master 1 more slave. * so It allocates dictSize(master->slaves) + 1 */ slaves = zmalloc(sizeof(sentinelAddr*)*(dictSize(master->slaves) + 1)); /* Don't include the one having the address we are switching to. */ di = dictGetIterator(master->slaves); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *slave = dictGetVal(de); if (sentinelAddrIsEqual(slave->addr,newaddr)) continue; slaves[numslaves++] = dupSentinelAddr(slave->addr); } dictReleaseIterator(di); /* If we are switching to a different address, include the old address * as a slave as well, so that we'll be able to sense / reconfigure * the old master. */ if (!sentinelAddrIsEqual(newaddr,master->addr)) { slaves[numslaves++] = dupSentinelAddr(master->addr); } /* Reset and switch address. */ sentinelResetMaster(master,SENTINEL_RESET_NO_SENTINELS); oldaddr = master->addr; master->addr = newaddr; master->o_down_since_time = 0; master->s_down_since_time = 0; /* Add slaves back. */ for (j = 0; j < numslaves; j++) { sentinelRedisInstance *slave; slave = createSentinelRedisInstance(NULL,SRI_SLAVE,slaves[j]->hostname, slaves[j]->port, master->quorum, master); releaseSentinelAddr(slaves[j]); if (slave) sentinelEvent(LL_NOTICE,"+slave",slave,"%@"); } zfree(slaves); /* Release the old address at the end so we are safe even if the function * gets the master->addr->ip and master->addr->port as arguments. */ releaseSentinelAddr(oldaddr); sentinelFlushConfig(); return C_OK; } /* Return non-zero if there was no SDOWN or ODOWN error associated to this * instance in the latest 'ms' milliseconds. */ int sentinelRedisInstanceNoDownFor(sentinelRedisInstance *ri, mstime_t ms) { mstime_t most_recent; most_recent = ri->s_down_since_time; if (ri->o_down_since_time > most_recent) most_recent = ri->o_down_since_time; return most_recent == 0 || (mstime() - most_recent) > ms; } /* Return the current master address, that is, its address or the address * of the promoted slave if already operational. */ sentinelAddr *sentinelGetCurrentMasterAddress(sentinelRedisInstance *master) { /* If we are failing over the master, and the state is already * SENTINEL_FAILOVER_STATE_RECONF_SLAVES or greater, it means that we * already have the new configuration epoch in the master, and the * slave acknowledged the configuration switch. Advertise the new * address. */ if ((master->flags & SRI_FAILOVER_IN_PROGRESS) && master->promoted_slave && master->failover_state >= SENTINEL_FAILOVER_STATE_RECONF_SLAVES) { return master->promoted_slave->addr; } else { return master->addr; } } /* This function sets the down_after_period field value in 'master' to all * the slaves and sentinel instances connected to this master. */ void sentinelPropagateDownAfterPeriod(sentinelRedisInstance *master) { dictIterator *di; dictEntry *de; int j; dict *d[] = {master->slaves, master->sentinels, NULL}; for (j = 0; d[j]; j++) { di = dictGetIterator(d[j]); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); ri->down_after_period = master->down_after_period; } dictReleaseIterator(di); } } /* This function is used in order to send commands to Redis instances: the * commands we send from Sentinel may be renamed, a common case is a master * with CONFIG and SLAVEOF commands renamed for security concerns. In that * case we check the ri->renamed_command table (or if the instance is a slave, * we check the one of the master), and map the command that we should send * to the set of renamed commands. However, if the command was not renamed, * we just return "command" itself. */ char *sentinelInstanceMapCommand(sentinelRedisInstance *ri, char *command) { sds sc = sdsnew(command); if (ri->master) ri = ri->master; char *retval = dictFetchValue(ri->renamed_commands, sc); sdsfree(sc); return retval ? retval : command; } /* ============================ Config handling ============================= */ /* Generalise handling create instance error. Use SRI_MASTER, SRI_SLAVE or * SRI_SENTINEL as a role value. */ const char *sentinelCheckCreateInstanceErrors(int role) { switch(errno) { case EBUSY: switch (role) { case SRI_MASTER: return "Duplicate master name."; case SRI_SLAVE: return "Duplicate hostname and port for replica."; case SRI_SENTINEL: return "Duplicate runid for sentinel."; default: serverAssert(0); break; } break; case ENOENT: return "Can't resolve instance hostname."; case EINVAL: return "Invalid port number."; default: return "Unknown Error for creating instances."; } } /* init function for server.sentinel_config */ void initializeSentinelConfig() { server.sentinel_config = zmalloc(sizeof(struct sentinelConfig)); server.sentinel_config->monitor_cfg = listCreate(); server.sentinel_config->pre_monitor_cfg = listCreate(); server.sentinel_config->post_monitor_cfg = listCreate(); listSetFreeMethod(server.sentinel_config->monitor_cfg,freeSentinelLoadQueueEntry); listSetFreeMethod(server.sentinel_config->pre_monitor_cfg,freeSentinelLoadQueueEntry); listSetFreeMethod(server.sentinel_config->post_monitor_cfg,freeSentinelLoadQueueEntry); } /* destroy function for server.sentinel_config */ void freeSentinelConfig() { /* release these three config queues since we will not use it anymore */ listRelease(server.sentinel_config->pre_monitor_cfg); listRelease(server.sentinel_config->monitor_cfg); listRelease(server.sentinel_config->post_monitor_cfg); zfree(server.sentinel_config); server.sentinel_config = NULL; } /* Search config name in pre monitor config name array, return 1 if found, * 0 if not found. */ int searchPreMonitorCfgName(const char *name) { for (unsigned int i = 0; i < sizeof(preMonitorCfgName)/sizeof(preMonitorCfgName[0]); i++) { if (!strcasecmp(preMonitorCfgName[i],name)) return 1; } return 0; } /* free method for sentinelLoadQueueEntry when release the list */ void freeSentinelLoadQueueEntry(void *item) { struct sentinelLoadQueueEntry *entry = item; sdsfreesplitres(entry->argv,entry->argc); sdsfree(entry->line); zfree(entry); } /* This function is used for queuing sentinel configuration, the main * purpose of this function is to delay parsing the sentinel config option * in order to avoid the order dependent issue from the config. */ void queueSentinelConfig(sds *argv, int argc, int linenum, sds line) { int i; struct sentinelLoadQueueEntry *entry; /* initialize sentinel_config for the first call */ if (server.sentinel_config == NULL) initializeSentinelConfig(); entry = zmalloc(sizeof(struct sentinelLoadQueueEntry)); entry->argv = zmalloc(sizeof(char*)*argc); entry->argc = argc; entry->linenum = linenum; entry->line = sdsdup(line); for (i = 0; i < argc; i++) { entry->argv[i] = sdsdup(argv[i]); } /* Separate config lines with pre monitor config, monitor config and * post monitor config, in order to parsing config dependencies * correctly. */ if (!strcasecmp(argv[0],"monitor")) { listAddNodeTail(server.sentinel_config->monitor_cfg,entry); } else if (searchPreMonitorCfgName(argv[0])) { listAddNodeTail(server.sentinel_config->pre_monitor_cfg,entry); } else{ listAddNodeTail(server.sentinel_config->post_monitor_cfg,entry); } } /* This function is used for loading the sentinel configuration from * pre_monitor_cfg, monitor_cfg and post_monitor_cfg list */ void loadSentinelConfigFromQueue(void) { const char *err = NULL; listIter li; listNode *ln; int linenum = 0; sds line = NULL; /* if there is no sentinel_config entry, we can return immediately */ if (server.sentinel_config == NULL) return; /* loading from pre monitor config queue first to avoid dependency issues */ listRewind(server.sentinel_config->pre_monitor_cfg,&li); while((ln = listNext(&li))) { struct sentinelLoadQueueEntry *entry = ln->value; err = sentinelHandleConfiguration(entry->argv,entry->argc); if (err) { linenum = entry->linenum; line = entry->line; goto loaderr; } } /* loading from monitor config queue */ listRewind(server.sentinel_config->monitor_cfg,&li); while((ln = listNext(&li))) { struct sentinelLoadQueueEntry *entry = ln->value; err = sentinelHandleConfiguration(entry->argv,entry->argc); if (err) { linenum = entry->linenum; line = entry->line; goto loaderr; } } /* loading from the post monitor config queue */ listRewind(server.sentinel_config->post_monitor_cfg,&li); while((ln = listNext(&li))) { struct sentinelLoadQueueEntry *entry = ln->value; err = sentinelHandleConfiguration(entry->argv,entry->argc); if (err) { linenum = entry->linenum; line = entry->line; goto loaderr; } } /* free sentinel_config when config loading is finished */ freeSentinelConfig(); return; loaderr: fprintf(stderr, "\n*** FATAL CONFIG FILE ERROR (Redis %s) ***\n", REDIS_VERSION); fprintf(stderr, "Reading the configuration file, at line %d\n", linenum); fprintf(stderr, ">>> '%s'\n", line); fprintf(stderr, "%s\n", err); exit(1); } const char *sentinelHandleConfiguration(char **argv, int argc) { sentinelRedisInstance *ri; if (!strcasecmp(argv[0],"monitor") && argc == 5) { /* monitor */ int quorum = atoi(argv[4]); if (quorum <= 0) return "Quorum must be 1 or greater."; if (createSentinelRedisInstance(argv[1],SRI_MASTER,argv[2], atoi(argv[3]),quorum,NULL) == NULL) { return sentinelCheckCreateInstanceErrors(SRI_MASTER); } } else if (!strcasecmp(argv[0],"down-after-milliseconds") && argc == 3) { /* down-after-milliseconds */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->down_after_period = atoi(argv[2]); if (ri->down_after_period <= 0) return "negative or zero time parameter."; sentinelPropagateDownAfterPeriod(ri); } else if (!strcasecmp(argv[0],"failover-timeout") && argc == 3) { /* failover-timeout */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->failover_timeout = atoi(argv[2]); if (ri->failover_timeout <= 0) return "negative or zero time parameter."; } else if (!strcasecmp(argv[0],"parallel-syncs") && argc == 3) { /* parallel-syncs */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->parallel_syncs = atoi(argv[2]); } else if (!strcasecmp(argv[0],"notification-script") && argc == 3) { /* notification-script */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; if (access(argv[2],X_OK) == -1) return "Notification script seems non existing or non executable."; ri->notification_script = sdsnew(argv[2]); } else if (!strcasecmp(argv[0],"client-reconfig-script") && argc == 3) { /* client-reconfig-script */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; if (access(argv[2],X_OK) == -1) return "Client reconfiguration script seems non existing or " "non executable."; ri->client_reconfig_script = sdsnew(argv[2]); } else if (!strcasecmp(argv[0],"auth-pass") && argc == 3) { /* auth-pass */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->auth_pass = sdsnew(argv[2]); } else if (!strcasecmp(argv[0],"auth-user") && argc == 3) { /* auth-user */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->auth_user = sdsnew(argv[2]); } else if (!strcasecmp(argv[0],"current-epoch") && argc == 2) { /* current-epoch */ unsigned long long current_epoch = strtoull(argv[1],NULL,10); if (current_epoch > sentinel.current_epoch) sentinel.current_epoch = current_epoch; } else if (!strcasecmp(argv[0],"myid") && argc == 2) { if (strlen(argv[1]) != CONFIG_RUN_ID_SIZE) return "Malformed Sentinel id in myid option."; memcpy(sentinel.myid,argv[1],CONFIG_RUN_ID_SIZE); } else if (!strcasecmp(argv[0],"config-epoch") && argc == 3) { /* config-epoch */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->config_epoch = strtoull(argv[2],NULL,10); /* The following update of current_epoch is not really useful as * now the current epoch is persisted on the config file, but * we leave this check here for redundancy. */ if (ri->config_epoch > sentinel.current_epoch) sentinel.current_epoch = ri->config_epoch; } else if (!strcasecmp(argv[0],"leader-epoch") && argc == 3) { /* leader-epoch */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; ri->leader_epoch = strtoull(argv[2],NULL,10); } else if ((!strcasecmp(argv[0],"known-slave") || !strcasecmp(argv[0],"known-replica")) && argc == 4) { sentinelRedisInstance *slave; /* known-replica */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; if ((slave = createSentinelRedisInstance(NULL,SRI_SLAVE,argv[2], atoi(argv[3]), ri->quorum, ri)) == NULL) { return sentinelCheckCreateInstanceErrors(SRI_SLAVE); } } else if (!strcasecmp(argv[0],"known-sentinel") && (argc == 4 || argc == 5)) { sentinelRedisInstance *si; if (argc == 5) { /* Ignore the old form without runid. */ /* known-sentinel [runid] */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; if ((si = createSentinelRedisInstance(argv[4],SRI_SENTINEL,argv[2], atoi(argv[3]), ri->quorum, ri)) == NULL) { return sentinelCheckCreateInstanceErrors(SRI_SENTINEL); } si->runid = sdsnew(argv[4]); sentinelTryConnectionSharing(si); } } else if (!strcasecmp(argv[0],"rename-command") && argc == 4) { /* rename-command */ ri = sentinelGetMasterByName(argv[1]); if (!ri) return "No such master with specified name."; sds oldcmd = sdsnew(argv[2]); sds newcmd = sdsnew(argv[3]); if (dictAdd(ri->renamed_commands,oldcmd,newcmd) != DICT_OK) { sdsfree(oldcmd); sdsfree(newcmd); return "Same command renamed multiple times with rename-command."; } } else if (!strcasecmp(argv[0],"announce-ip") && argc == 2) { /* announce-ip */ if (strlen(argv[1])) sentinel.announce_ip = sdsnew(argv[1]); } else if (!strcasecmp(argv[0],"announce-port") && argc == 2) { /* announce-port */ sentinel.announce_port = atoi(argv[1]); } else if (!strcasecmp(argv[0],"deny-scripts-reconfig") && argc == 2) { /* deny-scripts-reconfig */ if ((sentinel.deny_scripts_reconfig = yesnotoi(argv[1])) == -1) { return "Please specify yes or no for the " "deny-scripts-reconfig options."; } } else if (!strcasecmp(argv[0],"sentinel-user") && argc == 2) { /* sentinel-user */ if (strlen(argv[1])) sentinel.sentinel_auth_user = sdsnew(argv[1]); } else if (!strcasecmp(argv[0],"sentinel-pass") && argc == 2) { /* sentinel-pass */ if (strlen(argv[1])) sentinel.sentinel_auth_pass = sdsnew(argv[1]); } else if (!strcasecmp(argv[0],"resolve-hostnames") && argc == 2) { /* resolve-hostnames */ if ((sentinel.resolve_hostnames = yesnotoi(argv[1])) == -1) { return "Please specify yes or no for the resolve-hostnames option."; } } else if (!strcasecmp(argv[0],"announce-hostnames") && argc == 2) { /* announce-hostnames */ if ((sentinel.announce_hostnames = yesnotoi(argv[1])) == -1) { return "Please specify yes or no for the announce-hostnames option."; } } else { return "Unrecognized sentinel configuration statement."; } return NULL; } /* Implements CONFIG REWRITE for "sentinel" option. * This is used not just to rewrite the configuration given by the user * (the configured masters) but also in order to retain the state of * Sentinel across restarts: config epoch of masters, associated slaves * and sentinel instances, and so forth. */ void rewriteConfigSentinelOption(struct rewriteConfigState *state) { dictIterator *di, *di2; dictEntry *de; sds line; /* sentinel unique ID. */ line = sdscatprintf(sdsempty(), "sentinel myid %s", sentinel.myid); rewriteConfigRewriteLine(state,"sentinel myid",line,1); /* sentinel deny-scripts-reconfig. */ line = sdscatprintf(sdsempty(), "sentinel deny-scripts-reconfig %s", sentinel.deny_scripts_reconfig ? "yes" : "no"); rewriteConfigRewriteLine(state,"sentinel deny-scripts-reconfig",line, sentinel.deny_scripts_reconfig != SENTINEL_DEFAULT_DENY_SCRIPTS_RECONFIG); /* sentinel resolve-hostnames. * This must be included early in the file so it is already in effect * when reading the file. */ line = sdscatprintf(sdsempty(), "sentinel resolve-hostnames %s", sentinel.resolve_hostnames ? "yes" : "no"); rewriteConfigRewriteLine(state,"sentinel resolve-hostnames",line, sentinel.resolve_hostnames != SENTINEL_DEFAULT_RESOLVE_HOSTNAMES); /* sentinel announce-hostnames. */ line = sdscatprintf(sdsempty(), "sentinel announce-hostnames %s", sentinel.announce_hostnames ? "yes" : "no"); rewriteConfigRewriteLine(state,"sentinel announce-hostnames",line, sentinel.announce_hostnames != SENTINEL_DEFAULT_ANNOUNCE_HOSTNAMES); /* For every master emit a "sentinel monitor" config entry. */ di = dictGetIterator(sentinel.masters); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *master, *ri; sentinelAddr *master_addr; /* sentinel monitor */ master = dictGetVal(de); master_addr = sentinelGetCurrentMasterAddress(master); line = sdscatprintf(sdsempty(),"sentinel monitor %s %s %d %d", master->name, announceSentinelAddr(master_addr), master_addr->port, master->quorum); rewriteConfigRewriteLine(state,"sentinel monitor",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ /* sentinel down-after-milliseconds */ if (master->down_after_period != SENTINEL_DEFAULT_DOWN_AFTER) { line = sdscatprintf(sdsempty(), "sentinel down-after-milliseconds %s %ld", master->name, (long) master->down_after_period); rewriteConfigRewriteLine(state,"sentinel down-after-milliseconds",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } /* sentinel failover-timeout */ if (master->failover_timeout != SENTINEL_DEFAULT_FAILOVER_TIMEOUT) { line = sdscatprintf(sdsempty(), "sentinel failover-timeout %s %ld", master->name, (long) master->failover_timeout); rewriteConfigRewriteLine(state,"sentinel failover-timeout",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } /* sentinel parallel-syncs */ if (master->parallel_syncs != SENTINEL_DEFAULT_PARALLEL_SYNCS) { line = sdscatprintf(sdsempty(), "sentinel parallel-syncs %s %d", master->name, master->parallel_syncs); rewriteConfigRewriteLine(state,"sentinel parallel-syncs",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } /* sentinel notification-script */ if (master->notification_script) { line = sdscatprintf(sdsempty(), "sentinel notification-script %s %s", master->name, master->notification_script); rewriteConfigRewriteLine(state,"sentinel notification-script",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } /* sentinel client-reconfig-script */ if (master->client_reconfig_script) { line = sdscatprintf(sdsempty(), "sentinel client-reconfig-script %s %s", master->name, master->client_reconfig_script); rewriteConfigRewriteLine(state,"sentinel client-reconfig-script",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } /* sentinel auth-pass & auth-user */ if (master->auth_pass) { line = sdscatprintf(sdsempty(), "sentinel auth-pass %s %s", master->name, master->auth_pass); rewriteConfigRewriteLine(state,"sentinel auth-pass",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } if (master->auth_user) { line = sdscatprintf(sdsempty(), "sentinel auth-user %s %s", master->name, master->auth_user); rewriteConfigRewriteLine(state,"sentinel auth-user",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } /* sentinel config-epoch */ line = sdscatprintf(sdsempty(), "sentinel config-epoch %s %llu", master->name, (unsigned long long) master->config_epoch); rewriteConfigRewriteLine(state,"sentinel config-epoch",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ /* sentinel leader-epoch */ line = sdscatprintf(sdsempty(), "sentinel leader-epoch %s %llu", master->name, (unsigned long long) master->leader_epoch); rewriteConfigRewriteLine(state,"sentinel leader-epoch",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ /* sentinel known-slave */ di2 = dictGetIterator(master->slaves); while((de = dictNext(di2)) != NULL) { sentinelAddr *slave_addr; ri = dictGetVal(de); slave_addr = ri->addr; /* If master_addr (obtained using sentinelGetCurrentMasterAddress() * so it may be the address of the promoted slave) is equal to this * slave's address, a failover is in progress and the slave was * already successfully promoted. So as the address of this slave * we use the old master address instead. */ if (sentinelAddrIsEqual(slave_addr,master_addr)) slave_addr = master->addr; line = sdscatprintf(sdsempty(), "sentinel known-replica %s %s %d", master->name, announceSentinelAddr(slave_addr), slave_addr->port); rewriteConfigRewriteLine(state,"sentinel known-replica",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } dictReleaseIterator(di2); /* sentinel known-sentinel */ di2 = dictGetIterator(master->sentinels); while((de = dictNext(di2)) != NULL) { ri = dictGetVal(de); if (ri->runid == NULL) continue; line = sdscatprintf(sdsempty(), "sentinel known-sentinel %s %s %d %s", master->name, announceSentinelAddr(ri->addr), ri->addr->port, ri->runid); rewriteConfigRewriteLine(state,"sentinel known-sentinel",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } dictReleaseIterator(di2); /* sentinel rename-command */ di2 = dictGetIterator(master->renamed_commands); while((de = dictNext(di2)) != NULL) { sds oldname = dictGetKey(de); sds newname = dictGetVal(de); line = sdscatprintf(sdsempty(), "sentinel rename-command %s %s %s", master->name, oldname, newname); rewriteConfigRewriteLine(state,"sentinel rename-command",line,1); /* rewriteConfigMarkAsProcessed is handled after the loop */ } dictReleaseIterator(di2); } /* sentinel current-epoch is a global state valid for all the masters. */ line = sdscatprintf(sdsempty(), "sentinel current-epoch %llu", (unsigned long long) sentinel.current_epoch); rewriteConfigRewriteLine(state,"sentinel current-epoch",line,1); /* sentinel announce-ip. */ if (sentinel.announce_ip) { line = sdsnew("sentinel announce-ip "); line = sdscatrepr(line, sentinel.announce_ip, sdslen(sentinel.announce_ip)); rewriteConfigRewriteLine(state,"sentinel announce-ip",line,1); } else { rewriteConfigMarkAsProcessed(state,"sentinel announce-ip"); } /* sentinel announce-port. */ if (sentinel.announce_port) { line = sdscatprintf(sdsempty(),"sentinel announce-port %d", sentinel.announce_port); rewriteConfigRewriteLine(state,"sentinel announce-port",line,1); } else { rewriteConfigMarkAsProcessed(state,"sentinel announce-port"); } /* sentinel sentinel-user. */ if (sentinel.sentinel_auth_user) { line = sdscatprintf(sdsempty(), "sentinel sentinel-user %s", sentinel.sentinel_auth_user); rewriteConfigRewriteLine(state,"sentinel sentinel-user",line,1); } else { rewriteConfigMarkAsProcessed(state,"sentinel sentinel-user"); } /* sentinel sentinel-pass. */ if (sentinel.sentinel_auth_pass) { line = sdscatprintf(sdsempty(), "sentinel sentinel-pass %s", sentinel.sentinel_auth_pass); rewriteConfigRewriteLine(state,"sentinel sentinel-pass",line,1); } else { rewriteConfigMarkAsProcessed(state,"sentinel sentinel-pass"); } dictReleaseIterator(di); /* NOTE: the purpose here is in case due to the state change, the config rewrite does not handle the configs, however, previously the config was set in the config file, rewriteConfigMarkAsProcessed should be put here to mark it as processed in order to delete the old config entry. */ rewriteConfigMarkAsProcessed(state,"sentinel monitor"); rewriteConfigMarkAsProcessed(state,"sentinel down-after-milliseconds"); rewriteConfigMarkAsProcessed(state,"sentinel failover-timeout"); rewriteConfigMarkAsProcessed(state,"sentinel parallel-syncs"); rewriteConfigMarkAsProcessed(state,"sentinel notification-script"); rewriteConfigMarkAsProcessed(state,"sentinel client-reconfig-script"); rewriteConfigMarkAsProcessed(state,"sentinel auth-pass"); rewriteConfigMarkAsProcessed(state,"sentinel auth-user"); rewriteConfigMarkAsProcessed(state,"sentinel config-epoch"); rewriteConfigMarkAsProcessed(state,"sentinel leader-epoch"); rewriteConfigMarkAsProcessed(state,"sentinel known-replica"); rewriteConfigMarkAsProcessed(state,"sentinel known-sentinel"); rewriteConfigMarkAsProcessed(state,"sentinel rename-command"); } /* This function uses the config rewriting Redis engine in order to persist * the state of the Sentinel in the current configuration file. * * Before returning the function calls fsync() against the generated * configuration file to make sure changes are committed to disk. * * On failure the function logs a warning on the Redis log. */ void sentinelFlushConfig(void) { int fd = -1; int saved_hz = server.hz; int rewrite_status; server.hz = CONFIG_DEFAULT_HZ; rewrite_status = rewriteConfig(server.configfile, 0); server.hz = saved_hz; if (rewrite_status == -1) goto werr; if ((fd = open(server.configfile,O_RDONLY)) == -1) goto werr; if (fsync(fd) == -1) goto werr; if (close(fd) == EOF) goto werr; return; werr: serverLog(LL_WARNING,"WARNING: Sentinel was not able to save the new configuration on disk!!!: %s", strerror(errno)); if (fd != -1) close(fd); } /* ====================== hiredis connection handling ======================= */ /* Send the AUTH command with the specified master password if needed. * Note that for slaves the password set for the master is used. * * In case this Sentinel requires a password as well, via the "requirepass" * configuration directive, we assume we should use the local password in * order to authenticate when connecting with the other Sentinels as well. * So basically all the Sentinels share the same password and use it to * authenticate reciprocally. * * We don't check at all if the command was successfully transmitted * to the instance as if it fails Sentinel will detect the instance down, * will disconnect and reconnect the link and so forth. */ void sentinelSendAuthIfNeeded(sentinelRedisInstance *ri, redisAsyncContext *c) { char *auth_pass = NULL; char *auth_user = NULL; if (ri->flags & SRI_MASTER) { auth_pass = ri->auth_pass; auth_user = ri->auth_user; } else if (ri->flags & SRI_SLAVE) { auth_pass = ri->master->auth_pass; auth_user = ri->master->auth_user; } else if (ri->flags & SRI_SENTINEL) { /* If sentinel_auth_user is NULL, AUTH will use default user with sentinel_auth_pass to authenticate */ if (sentinel.sentinel_auth_pass) { auth_pass = sentinel.sentinel_auth_pass; auth_user = sentinel.sentinel_auth_user; } else { /* Compatibility with old configs. requirepass is used * for both incoming and outgoing authentication. */ auth_pass = server.requirepass; auth_user = NULL; } } if (auth_pass && auth_user == NULL) { if (redisAsyncCommand(c, sentinelDiscardReplyCallback, ri, "%s %s", sentinelInstanceMapCommand(ri,"AUTH"), auth_pass) == C_OK) ri->link->pending_commands++; } else if (auth_pass && auth_user) { /* If we also have an username, use the ACL-style AUTH command * with two arguments, username and password. */ if (redisAsyncCommand(c, sentinelDiscardReplyCallback, ri, "%s %s %s", sentinelInstanceMapCommand(ri,"AUTH"), auth_user, auth_pass) == C_OK) ri->link->pending_commands++; } } /* Use CLIENT SETNAME to name the connection in the Redis instance as * sentinel-- * The connection type is "cmd" or "pubsub" as specified by 'type'. * * This makes it possible to list all the sentinel instances connected * to a Redis server with CLIENT LIST, grepping for a specific name format. */ void sentinelSetClientName(sentinelRedisInstance *ri, redisAsyncContext *c, char *type) { char name[64]; snprintf(name,sizeof(name),"sentinel-%.8s-%s",sentinel.myid,type); if (redisAsyncCommand(c, sentinelDiscardReplyCallback, ri, "%s SETNAME %s", sentinelInstanceMapCommand(ri,"CLIENT"), name) == C_OK) { ri->link->pending_commands++; } } static int instanceLinkNegotiateTLS(redisAsyncContext *context) { #ifndef USE_OPENSSL (void) context; #else if (!redis_tls_ctx) return C_ERR; SSL *ssl = SSL_new(redis_tls_client_ctx ? redis_tls_client_ctx : redis_tls_ctx); if (!ssl) return C_ERR; if (redisInitiateSSL(&context->c, ssl) == REDIS_ERR) return C_ERR; #endif return C_OK; } /* Create the async connections for the instance link if the link * is disconnected. Note that link->disconnected is true even if just * one of the two links (commands and pub/sub) is missing. */ void sentinelReconnectInstance(sentinelRedisInstance *ri) { if (ri->link->disconnected == 0) return; if (ri->addr->port == 0) return; /* port == 0 means invalid address. */ instanceLink *link = ri->link; mstime_t now = mstime(); if (now - ri->link->last_reconn_time < SENTINEL_PING_PERIOD) return; ri->link->last_reconn_time = now; /* Commands connection. */ if (link->cc == NULL) { link->cc = redisAsyncConnectBind(ri->addr->ip,ri->addr->port,NET_FIRST_BIND_ADDR); if (link->cc && !link->cc->err) anetCloexec(link->cc->c.fd); if (!link->cc) { sentinelEvent(LL_DEBUG,"-cmd-link-reconnection",ri,"%@ #Failed to establish connection"); } else if (!link->cc->err && server.tls_replication && (instanceLinkNegotiateTLS(link->cc) == C_ERR)) { sentinelEvent(LL_DEBUG,"-cmd-link-reconnection",ri,"%@ #Failed to initialize TLS"); instanceLinkCloseConnection(link,link->cc); } else if (link->cc->err) { sentinelEvent(LL_DEBUG,"-cmd-link-reconnection",ri,"%@ #%s", link->cc->errstr); instanceLinkCloseConnection(link,link->cc); } else { link->pending_commands = 0; link->cc_conn_time = mstime(); link->cc->data = link; redisAeAttach(server.el,link->cc); redisAsyncSetConnectCallback(link->cc, sentinelLinkEstablishedCallback); redisAsyncSetDisconnectCallback(link->cc, sentinelDisconnectCallback); sentinelSendAuthIfNeeded(ri,link->cc); sentinelSetClientName(ri,link->cc,"cmd"); /* Send a PING ASAP when reconnecting. */ sentinelSendPing(ri); } } /* Pub / Sub */ if ((ri->flags & (SRI_MASTER|SRI_SLAVE)) && link->pc == NULL) { link->pc = redisAsyncConnectBind(ri->addr->ip,ri->addr->port,NET_FIRST_BIND_ADDR); if (link->pc && !link->pc->err) anetCloexec(link->pc->c.fd); if (!link->pc) { sentinelEvent(LL_DEBUG,"-pubsub-link-reconnection",ri,"%@ #Failed to establish connection"); } else if (!link->pc->err && server.tls_replication && (instanceLinkNegotiateTLS(link->pc) == C_ERR)) { sentinelEvent(LL_DEBUG,"-pubsub-link-reconnection",ri,"%@ #Failed to initialize TLS"); } else if (link->pc->err) { sentinelEvent(LL_DEBUG,"-pubsub-link-reconnection",ri,"%@ #%s", link->pc->errstr); instanceLinkCloseConnection(link,link->pc); } else { int retval; link->pc_conn_time = mstime(); link->pc->data = link; redisAeAttach(server.el,link->pc); redisAsyncSetConnectCallback(link->pc, sentinelLinkEstablishedCallback); redisAsyncSetDisconnectCallback(link->pc, sentinelDisconnectCallback); sentinelSendAuthIfNeeded(ri,link->pc); sentinelSetClientName(ri,link->pc,"pubsub"); /* Now we subscribe to the Sentinels "Hello" channel. */ retval = redisAsyncCommand(link->pc, sentinelReceiveHelloMessages, ri, "%s %s", sentinelInstanceMapCommand(ri,"SUBSCRIBE"), SENTINEL_HELLO_CHANNEL); if (retval != C_OK) { /* If we can't subscribe, the Pub/Sub connection is useless * and we can simply disconnect it and try again. */ instanceLinkCloseConnection(link,link->pc); return; } } } /* Clear the disconnected status only if we have both the connections * (or just the commands connection if this is a sentinel instance). */ if (link->cc && (ri->flags & SRI_SENTINEL || link->pc)) link->disconnected = 0; } /* ======================== Redis instances pinging ======================== */ /* Return true if master looks "sane", that is: * 1) It is actually a master in the current configuration. * 2) It reports itself as a master. * 3) It is not SDOWN or ODOWN. * 4) We obtained last INFO no more than two times the INFO period time ago. */ int sentinelMasterLooksSane(sentinelRedisInstance *master) { return master->flags & SRI_MASTER && master->role_reported == SRI_MASTER && (master->flags & (SRI_S_DOWN|SRI_O_DOWN)) == 0 && (mstime() - master->info_refresh) < SENTINEL_INFO_PERIOD*2; } /* Process the INFO output from masters. */ void sentinelRefreshInstanceInfo(sentinelRedisInstance *ri, const char *info) { sds *lines; int numlines, j; int role = 0; /* cache full INFO output for instance */ sdsfree(ri->info); ri->info = sdsnew(info); /* The following fields must be reset to a given value in the case they * are not found at all in the INFO output. */ ri->master_link_down_time = 0; /* Process line by line. */ lines = sdssplitlen(info,strlen(info),"\r\n",2,&numlines); for (j = 0; j < numlines; j++) { sentinelRedisInstance *slave; sds l = lines[j]; /* run_id:<40 hex chars>*/ if (sdslen(l) >= 47 && !memcmp(l,"run_id:",7)) { if (ri->runid == NULL) { ri->runid = sdsnewlen(l+7,40); } else { if (strncmp(ri->runid,l+7,40) != 0) { sentinelEvent(LL_NOTICE,"+reboot",ri,"%@"); sdsfree(ri->runid); ri->runid = sdsnewlen(l+7,40); } } } /* old versions: slave0:,, * new versions: slave0:ip=127.0.0.1,port=9999,... */ if ((ri->flags & SRI_MASTER) && sdslen(l) >= 7 && !memcmp(l,"slave",5) && isdigit(l[5])) { char *ip, *port, *end; if (strstr(l,"ip=") == NULL) { /* Old format. */ ip = strchr(l,':'); if (!ip) continue; ip++; /* Now ip points to start of ip address. */ port = strchr(ip,','); if (!port) continue; *port = '\0'; /* nul term for easy access. */ port++; /* Now port points to start of port number. */ end = strchr(port,','); if (!end) continue; *end = '\0'; /* nul term for easy access. */ } else { /* New format. */ ip = strstr(l,"ip="); if (!ip) continue; ip += 3; /* Now ip points to start of ip address. */ port = strstr(l,"port="); if (!port) continue; port += 5; /* Now port points to start of port number. */ /* Nul term both fields for easy access. */ end = strchr(ip,','); if (end) *end = '\0'; end = strchr(port,','); if (end) *end = '\0'; } /* Check if we already have this slave into our table, * otherwise add it. */ if (sentinelRedisInstanceLookupSlave(ri,ip,atoi(port)) == NULL) { if ((slave = createSentinelRedisInstance(NULL,SRI_SLAVE,ip, atoi(port), ri->quorum, ri)) != NULL) { sentinelEvent(LL_NOTICE,"+slave",slave,"%@"); sentinelFlushConfig(); } } } /* master_link_down_since_seconds: */ if (sdslen(l) >= 32 && !memcmp(l,"master_link_down_since_seconds",30)) { ri->master_link_down_time = strtoll(l+31,NULL,10)*1000; } /* role: */ if (sdslen(l) >= 11 && !memcmp(l,"role:master",11)) role = SRI_MASTER; else if (sdslen(l) >= 10 && !memcmp(l,"role:slave",10)) role = SRI_SLAVE; if (role == SRI_SLAVE) { /* master_host: */ if (sdslen(l) >= 12 && !memcmp(l,"master_host:",12)) { if (ri->slave_master_host == NULL || strcasecmp(l+12,ri->slave_master_host)) { sdsfree(ri->slave_master_host); ri->slave_master_host = sdsnew(l+12); ri->slave_conf_change_time = mstime(); } } /* master_port: */ if (sdslen(l) >= 12 && !memcmp(l,"master_port:",12)) { int slave_master_port = atoi(l+12); if (ri->slave_master_port != slave_master_port) { ri->slave_master_port = slave_master_port; ri->slave_conf_change_time = mstime(); } } /* master_link_status: */ if (sdslen(l) >= 19 && !memcmp(l,"master_link_status:",19)) { ri->slave_master_link_status = (strcasecmp(l+19,"up") == 0) ? SENTINEL_MASTER_LINK_STATUS_UP : SENTINEL_MASTER_LINK_STATUS_DOWN; } /* slave_priority: */ if (sdslen(l) >= 15 && !memcmp(l,"slave_priority:",15)) ri->slave_priority = atoi(l+15); /* slave_repl_offset: */ if (sdslen(l) >= 18 && !memcmp(l,"slave_repl_offset:",18)) ri->slave_repl_offset = strtoull(l+18,NULL,10); /* replica_announced: */ if (sdslen(l) >= 18 && !memcmp(l,"replica_announced:",18)) ri->replica_announced = atoi(l+18); } } ri->info_refresh = mstime(); sdsfreesplitres(lines,numlines); /* ---------------------------- Acting half ----------------------------- * Some things will not happen if sentinel.tilt is true, but some will * still be processed. */ /* Remember when the role changed. */ if (role != ri->role_reported) { ri->role_reported_time = mstime(); ri->role_reported = role; if (role == SRI_SLAVE) ri->slave_conf_change_time = mstime(); /* Log the event with +role-change if the new role is coherent or * with -role-change if there is a mismatch with the current config. */ sentinelEvent(LL_VERBOSE, ((ri->flags & (SRI_MASTER|SRI_SLAVE)) == role) ? "+role-change" : "-role-change", ri, "%@ new reported role is %s", role == SRI_MASTER ? "master" : "slave"); } /* None of the following conditions are processed when in tilt mode, so * return asap. */ if (sentinel.tilt) return; /* Handle master -> slave role switch. */ if ((ri->flags & SRI_MASTER) && role == SRI_SLAVE) { /* Nothing to do, but masters claiming to be slaves are * considered to be unreachable by Sentinel, so eventually * a failover will be triggered. */ } /* Handle slave -> master role switch. */ if ((ri->flags & SRI_SLAVE) && role == SRI_MASTER) { /* If this is a promoted slave we can change state to the * failover state machine. */ if ((ri->flags & SRI_PROMOTED) && (ri->master->flags & SRI_FAILOVER_IN_PROGRESS) && (ri->master->failover_state == SENTINEL_FAILOVER_STATE_WAIT_PROMOTION)) { /* Now that we are sure the slave was reconfigured as a master * set the master configuration epoch to the epoch we won the * election to perform this failover. This will force the other * Sentinels to update their config (assuming there is not * a newer one already available). */ ri->master->config_epoch = ri->master->failover_epoch; ri->master->failover_state = SENTINEL_FAILOVER_STATE_RECONF_SLAVES; ri->master->failover_state_change_time = mstime(); sentinelFlushConfig(); sentinelEvent(LL_WARNING,"+promoted-slave",ri,"%@"); if (sentinel.simfailure_flags & SENTINEL_SIMFAILURE_CRASH_AFTER_PROMOTION) sentinelSimFailureCrash(); sentinelEvent(LL_WARNING,"+failover-state-reconf-slaves", ri->master,"%@"); sentinelCallClientReconfScript(ri->master,SENTINEL_LEADER, "start",ri->master->addr,ri->addr); sentinelForceHelloUpdateForMaster(ri->master); } else { /* A slave turned into a master. We want to force our view and * reconfigure as slave. Wait some time after the change before * going forward, to receive new configs if any. */ mstime_t wait_time = SENTINEL_PUBLISH_PERIOD*4; if (!(ri->flags & SRI_PROMOTED) && sentinelMasterLooksSane(ri->master) && sentinelRedisInstanceNoDownFor(ri,wait_time) && mstime() - ri->role_reported_time > wait_time) { int retval = sentinelSendSlaveOf(ri,ri->master->addr); if (retval == C_OK) sentinelEvent(LL_NOTICE,"+convert-to-slave",ri,"%@"); } } } /* Handle slaves replicating to a different master address. */ if ((ri->flags & SRI_SLAVE) && role == SRI_SLAVE && (ri->slave_master_port != ri->master->addr->port || !sentinelAddrEqualsHostname(ri->master->addr, ri->slave_master_host))) { mstime_t wait_time = ri->master->failover_timeout; /* Make sure the master is sane before reconfiguring this instance * into a slave. */ if (sentinelMasterLooksSane(ri->master) && sentinelRedisInstanceNoDownFor(ri,wait_time) && mstime() - ri->slave_conf_change_time > wait_time) { int retval = sentinelSendSlaveOf(ri,ri->master->addr); if (retval == C_OK) sentinelEvent(LL_NOTICE,"+fix-slave-config",ri,"%@"); } } /* Detect if the slave that is in the process of being reconfigured * changed state. */ if ((ri->flags & SRI_SLAVE) && role == SRI_SLAVE && (ri->flags & (SRI_RECONF_SENT|SRI_RECONF_INPROG))) { /* SRI_RECONF_SENT -> SRI_RECONF_INPROG. */ if ((ri->flags & SRI_RECONF_SENT) && ri->slave_master_host && sentinelAddrEqualsHostname(ri->master->promoted_slave->addr, ri->slave_master_host) && ri->slave_master_port == ri->master->promoted_slave->addr->port) { ri->flags &= ~SRI_RECONF_SENT; ri->flags |= SRI_RECONF_INPROG; sentinelEvent(LL_NOTICE,"+slave-reconf-inprog",ri,"%@"); } /* SRI_RECONF_INPROG -> SRI_RECONF_DONE */ if ((ri->flags & SRI_RECONF_INPROG) && ri->slave_master_link_status == SENTINEL_MASTER_LINK_STATUS_UP) { ri->flags &= ~SRI_RECONF_INPROG; ri->flags |= SRI_RECONF_DONE; sentinelEvent(LL_NOTICE,"+slave-reconf-done",ri,"%@"); } } } void sentinelInfoReplyCallback(redisAsyncContext *c, void *reply, void *privdata) { sentinelRedisInstance *ri = privdata; instanceLink *link = c->data; redisReply *r; if (!reply || !link) return; link->pending_commands--; r = reply; if (r->type == REDIS_REPLY_STRING) sentinelRefreshInstanceInfo(ri,r->str); } /* Just discard the reply. We use this when we are not monitoring the return * value of the command but its effects directly. */ void sentinelDiscardReplyCallback(redisAsyncContext *c, void *reply, void *privdata) { instanceLink *link = c->data; UNUSED(reply); UNUSED(privdata); if (link) link->pending_commands--; } void sentinelPingReplyCallback(redisAsyncContext *c, void *reply, void *privdata) { sentinelRedisInstance *ri = privdata; instanceLink *link = c->data; redisReply *r; if (!reply || !link) return; link->pending_commands--; r = reply; if (r->type == REDIS_REPLY_STATUS || r->type == REDIS_REPLY_ERROR) { /* Update the "instance available" field only if this is an * acceptable reply. */ if (strncmp(r->str,"PONG",4) == 0 || strncmp(r->str,"LOADING",7) == 0 || strncmp(r->str,"MASTERDOWN",10) == 0) { link->last_avail_time = mstime(); link->act_ping_time = 0; /* Flag the pong as received. */ } else { /* Send a SCRIPT KILL command if the instance appears to be * down because of a busy script. */ if (strncmp(r->str,"BUSY",4) == 0 && (ri->flags & SRI_S_DOWN) && !(ri->flags & SRI_SCRIPT_KILL_SENT)) { if (redisAsyncCommand(ri->link->cc, sentinelDiscardReplyCallback, ri, "%s KILL", sentinelInstanceMapCommand(ri,"SCRIPT")) == C_OK) { ri->link->pending_commands++; } ri->flags |= SRI_SCRIPT_KILL_SENT; } } } link->last_pong_time = mstime(); } /* This is called when we get the reply about the PUBLISH command we send * to the master to advertise this sentinel. */ void sentinelPublishReplyCallback(redisAsyncContext *c, void *reply, void *privdata) { sentinelRedisInstance *ri = privdata; instanceLink *link = c->data; redisReply *r; if (!reply || !link) return; link->pending_commands--; r = reply; /* Only update pub_time if we actually published our message. Otherwise * we'll retry again in 100 milliseconds. */ if (r->type != REDIS_REPLY_ERROR) ri->last_pub_time = mstime(); } /* Process a hello message received via Pub/Sub in master or slave instance, * or sent directly to this sentinel via the (fake) PUBLISH command of Sentinel. * * If the master name specified in the message is not known, the message is * discarded. */ void sentinelProcessHelloMessage(char *hello, int hello_len) { /* Format is composed of 8 tokens: * 0=ip,1=port,2=runid,3=current_epoch,4=master_name, * 5=master_ip,6=master_port,7=master_config_epoch. */ int numtokens, port, removed, master_port; uint64_t current_epoch, master_config_epoch; char **token = sdssplitlen(hello, hello_len, ",", 1, &numtokens); sentinelRedisInstance *si, *master; if (numtokens == 8) { /* Obtain a reference to the master this hello message is about */ master = sentinelGetMasterByName(token[4]); if (!master) goto cleanup; /* Unknown master, skip the message. */ /* First, try to see if we already have this sentinel. */ port = atoi(token[1]); master_port = atoi(token[6]); si = getSentinelRedisInstanceByAddrAndRunID( master->sentinels,token[0],port,token[2]); current_epoch = strtoull(token[3],NULL,10); master_config_epoch = strtoull(token[7],NULL,10); if (!si) { /* If not, remove all the sentinels that have the same runid * because there was an address change, and add the same Sentinel * with the new address back. */ removed = removeMatchingSentinelFromMaster(master,token[2]); if (removed) { sentinelEvent(LL_NOTICE,"+sentinel-address-switch",master, "%@ ip %s port %d for %s", token[0],port,token[2]); } else { /* Check if there is another Sentinel with the same address this * new one is reporting. What we do if this happens is to set its * port to 0, to signal the address is invalid. We'll update it * later if we get an HELLO message. */ sentinelRedisInstance *other = getSentinelRedisInstanceByAddrAndRunID( master->sentinels, token[0],port,NULL); if (other) { sentinelEvent(LL_NOTICE,"+sentinel-invalid-addr",other,"%@"); other->addr->port = 0; /* It means: invalid address. */ sentinelUpdateSentinelAddressInAllMasters(other); } } /* Add the new sentinel. */ si = createSentinelRedisInstance(token[2],SRI_SENTINEL, token[0],port,master->quorum,master); if (si) { if (!removed) sentinelEvent(LL_NOTICE,"+sentinel",si,"%@"); /* The runid is NULL after a new instance creation and * for Sentinels we don't have a later chance to fill it, * so do it now. */ si->runid = sdsnew(token[2]); sentinelTryConnectionSharing(si); if (removed) sentinelUpdateSentinelAddressInAllMasters(si); sentinelFlushConfig(); } } /* Update local current_epoch if received current_epoch is greater.*/ if (current_epoch > sentinel.current_epoch) { sentinel.current_epoch = current_epoch; sentinelFlushConfig(); sentinelEvent(LL_WARNING,"+new-epoch",master,"%llu", (unsigned long long) sentinel.current_epoch); } /* Update master info if received configuration is newer. */ if (si && master->config_epoch < master_config_epoch) { master->config_epoch = master_config_epoch; if (master_port != master->addr->port || !sentinelAddrEqualsHostname(master->addr, token[5])) { sentinelAddr *old_addr; sentinelEvent(LL_WARNING,"+config-update-from",si,"%@"); sentinelEvent(LL_WARNING,"+switch-master", master,"%s %s %d %s %d", master->name, announceSentinelAddr(master->addr), master->addr->port, token[5], master_port); old_addr = dupSentinelAddr(master->addr); sentinelResetMasterAndChangeAddress(master, token[5], master_port); sentinelCallClientReconfScript(master, SENTINEL_OBSERVER,"start", old_addr,master->addr); releaseSentinelAddr(old_addr); } } /* Update the state of the Sentinel. */ if (si) si->last_hello_time = mstime(); } cleanup: sdsfreesplitres(token,numtokens); } /* This is our Pub/Sub callback for the Hello channel. It's useful in order * to discover other sentinels attached at the same master. */ void sentinelReceiveHelloMessages(redisAsyncContext *c, void *reply, void *privdata) { sentinelRedisInstance *ri = privdata; redisReply *r; UNUSED(c); if (!reply || !ri) return; r = reply; /* Update the last activity in the pubsub channel. Note that since we * receive our messages as well this timestamp can be used to detect * if the link is probably disconnected even if it seems otherwise. */ ri->link->pc_last_activity = mstime(); /* Sanity check in the reply we expect, so that the code that follows * can avoid to check for details. */ if (r->type != REDIS_REPLY_ARRAY || r->elements != 3 || r->element[0]->type != REDIS_REPLY_STRING || r->element[1]->type != REDIS_REPLY_STRING || r->element[2]->type != REDIS_REPLY_STRING || strcmp(r->element[0]->str,"message") != 0) return; /* We are not interested in meeting ourselves */ if (strstr(r->element[2]->str,sentinel.myid) != NULL) return; sentinelProcessHelloMessage(r->element[2]->str, r->element[2]->len); } /* Send a "Hello" message via Pub/Sub to the specified 'ri' Redis * instance in order to broadcast the current configuration for this * master, and to advertise the existence of this Sentinel at the same time. * * The message has the following format: * * sentinel_ip,sentinel_port,sentinel_runid,current_epoch, * master_name,master_ip,master_port,master_config_epoch. * * Returns C_OK if the PUBLISH was queued correctly, otherwise * C_ERR is returned. */ int sentinelSendHello(sentinelRedisInstance *ri) { char ip[NET_IP_STR_LEN]; char payload[NET_IP_STR_LEN+1024]; int retval; char *announce_ip; int announce_port; sentinelRedisInstance *master = (ri->flags & SRI_MASTER) ? ri : ri->master; sentinelAddr *master_addr = sentinelGetCurrentMasterAddress(master); if (ri->link->disconnected) return C_ERR; /* Use the specified announce address if specified, otherwise try to * obtain our own IP address. */ if (sentinel.announce_ip) { announce_ip = sentinel.announce_ip; } else { if (anetFdToString(ri->link->cc->c.fd,ip,sizeof(ip),NULL,FD_TO_SOCK_NAME) == -1) return C_ERR; announce_ip = ip; } if (sentinel.announce_port) announce_port = sentinel.announce_port; else if (server.tls_replication && server.tls_port) announce_port = server.tls_port; else announce_port = server.port; /* Format and send the Hello message. */ snprintf(payload,sizeof(payload), "%s,%d,%s,%llu," /* Info about this sentinel. */ "%s,%s,%d,%llu", /* Info about current master. */ announce_ip, announce_port, sentinel.myid, (unsigned long long) sentinel.current_epoch, /* --- */ master->name,announceSentinelAddr(master_addr),master_addr->port, (unsigned long long) master->config_epoch); retval = redisAsyncCommand(ri->link->cc, sentinelPublishReplyCallback, ri, "%s %s %s", sentinelInstanceMapCommand(ri,"PUBLISH"), SENTINEL_HELLO_CHANNEL,payload); if (retval != C_OK) return C_ERR; ri->link->pending_commands++; return C_OK; } /* Reset last_pub_time in all the instances in the specified dictionary * in order to force the delivery of a Hello update ASAP. */ void sentinelForceHelloUpdateDictOfRedisInstances(dict *instances) { dictIterator *di; dictEntry *de; di = dictGetSafeIterator(instances); while((de = dictNext(di)) != NULL) { sentinelRedisInstance *ri = dictGetVal(de); if (ri->last_pub_time >= (SENTINEL_PUBLISH_PERIOD+1)) ri->last_pub_time -= (SENTINEL_PUBLISH_PERIOD+1); } dictReleaseIterator(di); } /* This function forces the delivery of a "Hello" message (see * sentinelSendHello() top comment for further information) to all the Redis * and Sentinel instances related to the specified 'master'. * * It is technically not needed since we send an update to every instance * with a period of SENTINEL_PUBLISH_PERIOD milliseconds, however when a * Sentinel upgrades a configuration it is a good idea to deliver an update * to the other Sentinels ASAP. */ int sentinelForceHelloUpdateForMaster(sentinelRedisInstance *master) { if (!(master->flags & SRI_MASTER)) return C_ERR; if (master->last_pub_time >= (SENTINEL_PUBLISH_PERIOD+1)) master->last_pub_time -= (SENTINEL_PUBLISH_PERIOD+1); sentinelForceHelloUpdateDictOfRedisInstances(master->sentinels); sentinelForceHelloUpdateDictOfRedisInstances(master->slaves); return C_OK; } /* Send a PING to the specified instance and refresh the act_ping_time * if it is zero (that is, if we received a pong for the previous ping). * * On error zero is returned, and we can't consider the PING command * queued in the connection. */ int sentinelSendPing(sentinelRedisInstance *ri) { int retval = redisAsyncCommand(ri->link->cc, sentinelPingReplyCallback, ri, "%s", sentinelInstanceMapCommand(ri,"PING")); if (retval == C_OK) { ri->link->pending_commands++; ri->link->last_ping_time = mstime(); /* We update the active ping time only if we received the pong for * the previous ping, otherwise we are technically waiting since the * first ping that did not receive a reply. */ if (ri->link->act_ping_time == 0) ri->link->act_ping_time = ri->link->last_ping_time; return 1; } else { return 0; } } /* Send periodic PING, INFO, and PUBLISH to the Hello channel to * the specified master or slave instance. */ void sentinelSendPeriodicCommands(sentinelRedisInstance *ri) { mstime_t now = mstime(); mstime_t info_period, ping_period; int retval; /* Return ASAP if we have already a PING or INFO already pending, or * in the case the instance is not properly connected. */ if (ri->link->disconnected) return; /* For INFO, PING, PUBLISH that are not critical commands to send we * also have a limit of SENTINEL_MAX_PENDING_COMMANDS. We don't * want to use a lot of memory just because a link is not working * properly (note that anyway there is a redundant protection about this, * that is, the link will be disconnected and reconnected if a long * timeout condition is detected. */ if (ri->link->pending_commands >= SENTINEL_MAX_PENDING_COMMANDS * ri->link->refcount) return; /* If this is a slave of a master in O_DOWN condition we start sending * it INFO every second, instead of the usual SENTINEL_INFO_PERIOD * period. In this state we want to closely monitor slaves in case they * are turned into masters by another Sentinel, or by the sysadmin. * * Similarly we monitor the INFO output more often if the slave reports * to be disconnected from the master, so that we can have a fresh * disconnection time figure. */ if ((ri->flags & SRI_SLAVE) && ((ri->master->flags & (SRI_O_DOWN|SRI_FAILOVER_IN_PROGRESS)) || (ri->master_link_down_time != 0))) { info_period = 1000; } else { info_period = SENTINEL_INFO_PERIOD; } /* We ping instances every time the last received pong is older than * the configured 'down-after-milliseconds' time, but every second * anyway if 'down-after-milliseconds' is greater than 1 second. */ ping_period = ri->down_after_period; if (ping_period > SENTINEL_PING_PERIOD) ping_period = SENTINEL_PING_PERIOD; /* Send INFO to masters and slaves, not sentinels. */ if ((ri->flags & SRI_SENTINEL) == 0 && (ri->info_refresh == 0 || (now - ri->info_refresh) > info_period)) { retval = redisAsyncCommand(ri->link->cc, sentinelInfoReplyCallback, ri, "%s", sentinelInstanceMapCommand(ri,"INFO")); if (retval == C_OK) ri->link->pending_commands++; } /* Send PING to all the three kinds of instances. */ if ((now - ri->link->last_pong_time) > ping_period && (now - ri->link->last_ping_time) > ping_period/2) { sentinelSendPing(ri); } /* PUBLISH hello messages to all the three kinds of instances. */ if ((now - ri->last_pub_time) > SENTINEL_PUBLISH_PERIOD) { sentinelSendHello(ri); } } /* =========================== SENTINEL command ============================= */ /* SENTINEL CONFIG SET