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|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2001, 2012 Oracle and/or its affiliates. All rights reserved.
*
* $Id$
*/
#ifndef _DB_REP_H_
#define _DB_REP_H_
#include "dbinc_auto/rep_automsg.h"
#if defined(__cplusplus)
extern "C" {
#endif
/*
* Names of client temp databases.
*/
#define REPFILEPREFIX "__db.rep"
#define REPDBNAME "__db.rep.db"
#define REPPAGENAME "__db.reppg.db"
/*
* Name of replicated system database file, and LSN history subdatabase within
* it. If the INMEM config flag is set, we create the database in memory, with
* the REPLSNHIST name (so that is why it also follows the __db naming
* convention).
*/
#define REPSYSDBNAME "__db.rep.system"
#define REPLSNHIST "__db.lsn.history"
#define REPMEMBERSHIP "__db.membership"
#define REPSYSDBPGSZ 1024
#define IS_REP_FILE(name) (strcmp(name, REPSYSDBNAME) == 0)
/* Current version of commit token format, and LSN history database format. */
#define REP_COMMIT_TOKEN_FMT_VERSION 1
#define REP_LSN_HISTORY_FMT_VERSION 1
/*
* Message types
*/
#define REP_INVALID 0 /* Invalid message type. */
#define REP_ALIVE 1 /* I am alive message. */
#define REP_ALIVE_REQ 2 /* Request for alive messages. */
#define REP_ALL_REQ 3 /* Request all log records greater than LSN. */
#define REP_BULK_LOG 4 /* Bulk transfer of log records. */
#define REP_BULK_PAGE 5 /* Bulk transfer of pages. */
#define REP_DUPMASTER 6 /* Duplicate master detected; propagate. */
#define REP_FILE 7 /* Page of a database file. NOTUSED */
#define REP_FILE_FAIL 8 /* File requested does not exist. */
#define REP_FILE_REQ 9 /* Request for a database file. NOTUSED */
#define REP_LEASE_GRANT 10 /* Client grants a lease to a master. */
#define REP_LOG 11 /* Log record. */
#define REP_LOG_MORE 12 /* There are more log records to request. */
#define REP_LOG_REQ 13 /* Request for a log record. */
#define REP_MASTER_REQ 14 /* Who is the master */
#define REP_NEWCLIENT 15 /* Announces the presence of a new client. */
#define REP_NEWFILE 16 /* Announce a log file change. */
#define REP_NEWMASTER 17 /* Announces who the master is. */
#define REP_NEWSITE 18 /* Announces that a site has heard from a new
* site; like NEWCLIENT, but indirect. A
* NEWCLIENT message comes directly from the new
* client while a NEWSITE comes indirectly from
* someone who heard about a NEWSITE.
*/
#define REP_PAGE 19 /* Database page. */
#define REP_PAGE_FAIL 20 /* Requested page does not exist. */
#define REP_PAGE_MORE 21 /* There are more pages to request. */
#define REP_PAGE_REQ 22 /* Request for a database page. */
#define REP_REREQUEST 23 /* Force rerequest. */
#define REP_START_SYNC 24 /* Tell client to begin syncing a ckp.*/
#define REP_UPDATE 25 /* Environment hotcopy information. */
#define REP_UPDATE_REQ 26 /* Request for hotcopy information. */
#define REP_VERIFY 27 /* A log record for verification. */
#define REP_VERIFY_FAIL 28 /* The client is outdated. */
#define REP_VERIFY_REQ 29 /* Request for a log record to verify. */
#define REP_VOTE1 30 /* Send out your information for an election. */
#define REP_VOTE2 31 /* Send a "you are master" vote. */
/*
* Maximum message number for conversion tables. Update this
* value as the largest message number above increases.
* It might make processing messages more straightforward if
* the *_MORE and BULK* messages were flags within the regular
* message type instead of separate message types themselves.
*
* !!!
* NOTE: When changing messages above, the two tables for upgrade support
* need adjusting. They are in rep_util.c.
*/
#define REP_MAX_MSG 31
/*
* This is the list of client-to-client requests messages.
* We use this to decide if we're doing client-to-client and
* might need to send a rerequest.
*/
#define REP_MSG_REQ(rectype) \
(rectype == REP_ALL_REQ || \
rectype == REP_LOG_REQ || \
rectype == REP_PAGE_REQ || \
rectype == REP_VERIFY_REQ)
/*
* Note that the version information should be at the beginning of the
* structure, so that we can rearrange the rest of it while letting the
* version checks continue to work. DB_REPVERSION should be revved any time
* the rest of the structure changes or when the message numbers change.
*
* Define also, the corresponding log versions that are tied to the
* replication/release versions. These are only needed in replication
* and that is why they're defined here. db_printlog takes notice as well.
*/
#define DB_LOGVERSION_42 8
#define DB_LOGVERSION_43 10
#define DB_LOGVERSION_44 11
#define DB_LOGVERSION_45 12
#define DB_LOGVERSION_46 13
#define DB_LOGVERSION_47 14
#define DB_LOGVERSION_48 15
#define DB_LOGVERSION_48p2 16
#define DB_LOGVERSION_50 17
#define DB_LOGVERSION_51 17
#define DB_LOGVERSION_52 18
#define DB_LOGVERSION_53 19
#define DB_LOGVERSION_MIN DB_LOGVERSION_44
#define DB_REPVERSION_INVALID 0
#define DB_REPVERSION_44 3
#define DB_REPVERSION_45 3
#define DB_REPVERSION_46 4
#define DB_REPVERSION_47 5
#define DB_REPVERSION_48 5
#define DB_REPVERSION_50 5
#define DB_REPVERSION_51 5
#define DB_REPVERSION_52 6
#define DB_REPVERSION_53 7
#define DB_REPVERSION DB_REPVERSION_53
#define DB_REPVERSION_MIN DB_REPVERSION_44
/*
* RPRINT - Replication diagnostic output
* VPRINT - Replication verbose output (superset of RPRINT).
* REP_PRINT_MESSAGE
* Macros for verbose replication messages.
*
* Everything using RPRINT will go to the system diag file (if it
* is configured) and also to the user's verbose output if
* they have that verbose level configured.
* Messages using VPRINT do not ever go to the system diag file,
* but will go to the user's verbose output if configured.
*
* Use VPRINT for anything that might be printed on a standard,
* successful transaction. Use RPRINT for error paths, rep
* state changes, elections, etc.
*/
#define REP_DIAGNAME "__db.rep.diag%02d"
#define REP_DIAGSIZE MEGABYTE
#define RPRINT(env, x) do { \
if ((env)->dbenv->verbose != 0) \
(void)__rep_print_system x; \
} while (0)
#define VPRINT(env, x) do { \
if ((env)->dbenv->verbose != 0) \
(void)__rep_print x; \
} while (0)
#define REP_PRINT_MESSAGE(env, eid, rp, str, fl) do { \
if ((env)->dbenv->verbose != 0) \
__rep_print_message(env, eid, rp, str, fl); \
} while (0)
/*
* Election gen file name
* The file contains an egen number for an election this client has NOT
* participated in. I.e. it is the number of a future election. We
* create it when we create the rep region, if it doesn't already exist
* and initialize egen to 1. If it does exist, we read it when we create
* the rep region. We write it immediately before sending our VOTE1 in
* an election. That way, if a client has ever sent a vote for any
* election, the file is already going to be updated to reflect a future
* election, should it crash.
*/
#define REP_EGENNAME "__db.rep.egen"
#define REP_GENNAME "__db.rep.gen"
/*
* Internal init flag file name:
* The existence of this file serves as an indication that the client is in the
* process of Internal Initialization, in case it crashes before completing.
* During internal init the client's partially reconstructed database pages and
* logs may be in an inconsistent state, so much so that running recovery must
* be avoided. Furthermore, there is no other way to reliably recognize this
* condition. Therefore, when we open an environment, and we're just about to
* run recovery, we check for this file first. If it exists we must discard all
* logs and databases. This avoids the recovery problems, and leads to a fresh
* attempt at internal init if the environment becomes a replication client and
* finds a master. The list of databases which may need to be removed is stored
* in this file.
*/
#define REP_INITNAME "__db.rep.init"
#define REP_INITVERSION_46 1
#define REP_INITVERSION_47 2
#define REP_INITVERSION 3
/*
* Database types for __rep_client_dbinit
*/
typedef enum {
REP_DB, /* Log record database. */
REP_PG /* Pg database. */
} repdb_t;
/* Macros to lock/unlock the replication region as a whole. */
#define REP_SYSTEM_LOCK(env) \
MUTEX_LOCK(env, (env)->rep_handle->region->mtx_region)
#define REP_SYSTEM_UNLOCK(env) \
MUTEX_UNLOCK(env, (env)->rep_handle->region->mtx_region)
/*
* Macros for manipulating the event synchronization. We use a separate mutex
* so that an application's call-back function can be invoked without locking
* the whole region.
*/
#define REP_EVENT_LOCK(env) \
MUTEX_LOCK(env, (env)->rep_handle->region->mtx_event)
#define REP_EVENT_UNLOCK(env) \
MUTEX_UNLOCK(env, (env)->rep_handle->region->mtx_event)
/*
* Synchronization states
* Please change __rep_syncstate_to_string (rep_stat.c) to track any changes
* made to these states.
*
* The states are in alphabetical order (except for OFF). The usual
* order of progression for a full internal init is:
* VERIFY, UPDATE, PAGE, LOG (then back to OFF when we're done).
*/
typedef enum {
SYNC_OFF, /* No recovery. */
SYNC_LOG, /* Recovery - log. */
SYNC_PAGE, /* Recovery - pages. */
SYNC_UPDATE, /* Recovery - update. */
SYNC_VERIFY /* Recovery - verify. */
} repsync_t;
/*
* A record of the contents of the VOTE1 msg we sent out at current egen, in
* case we need to send out a duplicate VOTE1 to a late-joining client in a full
* election. The nsites, nvotes, and priority fields of the REP struct can't be
* used, because those could change. It's only safe to send out a dup if we
* send out the exact same info.
*/
typedef struct {
DB_LSN lsn;
u_int32_t nsites;
u_int32_t nvotes;
u_int32_t priority;
u_int32_t tiebreaker;
u_int32_t ctlflags;
u_int32_t data_gen;
} VOTE1_CONTENT;
/*
* REP --
* Shared replication structure.
*/
typedef struct __rep { /* SHARED */
db_mutex_t mtx_region; /* Region mutex. */
db_mutex_t mtx_clientdb; /* Client database mutex. */
db_mutex_t mtx_ckp; /* Checkpoint mutex. */
db_mutex_t mtx_diag; /* Diagnostic message mutex. */
db_mutex_t mtx_repstart; /* Role change mutex. */
int diag_index; /* Diagnostic file index. */
off_t diag_off; /* Diagnostic message offset. */
roff_t lease_off; /* Offset of the lease table. */
roff_t tally_off; /* Offset of the tally region. */
roff_t v2tally_off; /* Offset of the vote2 tally region. */
int eid; /* Environment id. */
int master_id; /* ID of the master site. */
u_int32_t version; /* Current replication version. */
u_int32_t egen; /* Replication election generation. */
u_int32_t spent_egen; /* Egen satisfied by rep_elect call. */
u_int32_t gen; /* Replication generation number. */
u_int32_t mgen; /* Master gen seen by client. */
u_int32_t asites; /* Space allocated for sites. */
u_int32_t nsites; /* Number of sites in group. */
u_int32_t nvotes; /* Number of votes needed. */
u_int32_t priority; /* My priority in an election. */
u_int32_t config_nsites;
db_timeout_t elect_timeout; /* Normal/full election timeouts. */
db_timeout_t full_elect_timeout;
db_timeout_t chkpt_delay; /* Master checkpoint delay. */
#define REP_DEFAULT_THROTTLE (10 * MEGABYTE) /* Default value is < 1Gig. */
u_int32_t gbytes; /* Limit on data sent in single... */
u_int32_t bytes; /* __rep_process_message call. */
#define DB_REP_REQUEST_GAP 40000 /* 40 msecs */
#define DB_REP_MAX_GAP 1280000 /* 1.28 seconds */
db_timespec request_gap; /* Minimum time to wait before we
* request a missing log record. */
db_timespec max_gap; /* Maximum time to wait before
* requesting a missing log record. */
/* Status change information */
u_int32_t apply_th; /* Number of callers in rep_apply. */
u_int32_t arch_th; /* Number of callers in log_archive. */
u_int32_t elect_th; /* Elect threads in lock-out. */
u_int32_t msg_th; /* Number of callers in rep_proc_msg.*/
u_int32_t handle_cnt; /* Count of handles in library. */
u_int32_t op_cnt; /* Multi-step operation count.*/
DB_LSN ckp_lsn; /* LSN for syncing a checkpoint. */
DB_LSN max_prep_lsn; /* Max LSN of txn_prepare record. */
/*
* Event notification synchronization: the mtx_event and associate
* fields which it protects govern event notification to the
* application. They form a guarantee that no matter how crazy the
* thread scheduling gets, the application sees a sensible, orderly
* progression of events.
*/
db_mutex_t mtx_event; /* Serializes event notification. */
/*
* Latest generation whose NEWMASTER event the application has been
* notified of. Also serves to force STARTUPDONE to occur after
* NEWMASTER.
*/
u_int32_t newmaster_event_gen;
/*
* Latest local victory of an election that the application has been
* notified of, expressed as the election generation number. This
* ensures we notify the application exactly once when it wins an
* election.
*/
u_int32_t notified_egen;
/* Internal init information. */
u_int32_t nfiles; /* Number of files we have info on. */
u_int32_t curfile; /* Cur file we're getting (0-based). */
roff_t originfo_off; /* Offset of original file info. */
u_int32_t infolen; /* Remaining length file info buffer. */
u_int32_t originfolen; /* Original length file info buffer. */
u_int32_t infoversion; /* Original file info version. */
DB_LSN first_lsn; /* Earliest LSN we need. */
u_int32_t first_vers; /* Log version of first log file. */
DB_LSN last_lsn; /* Latest LSN we need. */
/* These are protected by mtx_clientdb. */
db_timespec last_pg_ts; /* Last page stored timestamp. */
db_pgno_t ready_pg; /* Next pg expected. */
db_pgno_t waiting_pg; /* First pg after gap. */
db_pgno_t max_wait_pg; /* Maximum pg requested. */
u_int32_t npages; /* Num of pages rcvd for this file. */
roff_t curinfo_off; /* Offset of current file info. */
/* Always access with GET_CURINFO(). */
/* Vote tallying information. */
u_int32_t sites; /* Sites heard from. */
int winner; /* Current winner EID. */
u_int32_t w_priority; /* Winner priority. */
u_int32_t w_gen; /* Winner generation. */
u_int32_t w_datagen; /* Winner data generation. */
DB_LSN w_lsn; /* Winner LSN. */
u_int32_t w_tiebreaker; /* Winner tiebreaking value. */
u_int32_t votes; /* Number of votes for this site. */
VOTE1_CONTENT vote1; /* Valid until rep->egen changes. */
db_timespec etime; /* Election start timestamp. */
int full_elect; /* Is current election a "full" one? */
/* Leases. */
db_timeout_t lease_timeout; /* Lease timeout. */
db_timespec lease_duration; /* Lease timeout with clock skew. */
u_int32_t clock_skew; /* Clock skew. */
u_int32_t clock_base; /* Clock scale factor base. */
db_timespec grant_expire; /* Local grant expiration time. */
/* Cached LSN history, matching current gen. */
DB_LSN gen_base_lsn; /* Base LSN of current generation. */
u_int32_t master_envid; /* Current master's "unique" env ID. */
SH_TAILQ_HEAD(__wait) waiters; /* List of threads in txn_applied(). */
SH_TAILQ_HEAD(__wfree) free_waiters;/* Free list of waiter structs. */
#ifdef HAVE_REPLICATION_THREADS
/*
* Replication Framework (repmgr) shared config information.
*/
db_mutex_t mtx_repmgr; /* Region mutex. */
roff_t siteinfo_off; /* Offset of site array region. */
u_int site_cnt; /* Array slots in use. */
u_int site_max; /* Total array slots allocated. */
int self_eid; /* Where to find the local site. */
u_int siteinfo_seq; /* Number of updates to this info. */
u_int32_t min_log_file; /* Earliest log needed by repgroup. */
pid_t listener;
int perm_policy;
db_timeout_t ack_timeout;
db_timeout_t election_retry_wait;
db_timeout_t connection_retry_wait;
db_timeout_t heartbeat_frequency; /* Max period between msgs. */
db_timeout_t heartbeat_monitor_timeout;
#endif /* HAVE_REPLICATION_THREADS */
/* Statistics. */
DB_REP_STAT stat;
#if defined(HAVE_REPLICATION_THREADS) && defined(HAVE_STATISTICS)
DB_REPMGR_STAT mstat;
#endif
/*
* Please change __rep_print_all (rep_stat.c) to track any changes made
* to all these flag families below.
*/
/* Configuration. */
#define REP_C_2SITE_STRICT 0x00001 /* Don't cheat on elections. */
#define REP_C_AUTOINIT 0x00002 /* Auto initialization. */
#define REP_C_AUTOROLLBACK 0x00004 /* Discard client txns: sync. */
#define REP_C_BULK 0x00008 /* Bulk transfer. */
#define REP_C_DELAYCLIENT 0x00010 /* Delay client sync-up. */
#define REP_C_ELECTIONS 0x00020 /* Repmgr to use elections. */
#define REP_C_INMEM 0x00040 /* In-memory replication. */
#define REP_C_LEASE 0x00080 /* Leases configured. */
#define REP_C_NOWAIT 0x00100 /* Immediate error return. */
u_int32_t config; /* Configuration flags. */
/* Election. */
#define REP_E_PHASE0 0x00000001 /* In phase 0 of election. */
#define REP_E_PHASE1 0x00000002 /* In phase 1 of election. */
#define REP_E_PHASE2 0x00000004 /* In phase 2 of election. */
#define REP_E_TALLY 0x00000008 /* Tallied vote before elect. */
u_int32_t elect_flags; /* Election flags. */
/* Lockout. */
#define REP_LOCKOUT_API 0x00000001 /* BDB API - handle_cnt. */
#define REP_LOCKOUT_APPLY 0x00000002 /* apply msgs - apply_th. */
#define REP_LOCKOUT_ARCHIVE 0x00000004 /* log_archive. */
#define REP_LOCKOUT_MSG 0x00000008 /* Message process - msg_th. */
#define REP_LOCKOUT_OP 0x00000010 /* BDB ops txn,curs - op_cnt. */
u_int32_t lockout_flags; /* Lockout flags. */
/* See above for enumerated sync states. */
repsync_t sync_state; /* Recovery/synchronization flags. */
/*
* When adding a new flag value, consider whether it should be
* cleared in rep_start() when starting as a master or a client.
*/
#define REP_F_ABBREVIATED 0x00000001 /* Recover NIMDB pages only. */
#define REP_F_APP_BASEAPI 0x00000002 /* Base API application. */
#define REP_F_APP_REPMGR 0x00000004 /* repmgr application. */
#define REP_F_CLIENT 0x00000008 /* Client replica. */
#define REP_F_DELAY 0x00000010 /* Delaying client sync-up. */
#define REP_F_GROUP_ESTD 0x00000020 /* Rep group is established. */
#define REP_F_INUPDREQ 0x00000040 /* Thread in rep_update_req. */
#define REP_F_LEASE_EXPIRED 0x00000080 /* Leases guaranteed expired. */
#define REP_F_MASTER 0x00000100 /* Master replica. */
#define REP_F_MASTERELECT 0x00000200 /* Master elect. */
#define REP_F_NEWFILE 0x00000400 /* Newfile in progress. */
#define REP_F_NIMDBS_LOADED 0x00000800 /* NIMDBs are materialized. */
#define REP_F_SKIPPED_APPLY 0x00001000 /* Skipped applying a record. */
#define REP_F_START_CALLED 0x00002000 /* Rep_start called. */
#define REP_F_SYS_DB_OP 0x00004000 /* Operation in progress. */
u_int32_t flags;
} REP;
/* Information about a thread waiting in txn_applied(). */
typedef enum {
AWAIT_GEN, /* Client's gen is behind token gen. */
AWAIT_HISTORY, /* Haven't received master's LSN db update. */
AWAIT_LSN, /* Awaiting replication of user txn. */
AWAIT_NIMDB, /* LSN db missing: maybe it's INMEM. */
LOCKOUT /* Thread awoken due to pending lockout. */
} rep_waitreason_t;
struct rep_waitgoal {
rep_waitreason_t why;
union {
DB_LSN lsn; /* For AWAIT_LSN and AWAIT_HISTORY. */
u_int32_t gen; /* AWAIT_GEN */
} u;
};
struct __rep_waiter {
db_mutex_t mtx_repwait; /* Self-blocking mutex. */
struct rep_waitgoal goal;
SH_TAILQ_ENTRY links; /* On either free or waiting list. */
#define REP_F_PENDING_LOCKOUT 0x00000001
#define REP_F_WOKEN 0x00000002
u_int32_t flags;
};
/*
* Macros to check and clear the BDB lockouts. Currently they are
* locked out/set individually because they pertain to different pieces of
* the BDB API, they are otherwise always checked and cleared together.
*/
#define ISSET_LOCKOUT_BDB(R) \
(FLD_ISSET((R)->lockout_flags, (REP_LOCKOUT_API | REP_LOCKOUT_OP)))
#define CLR_LOCKOUT_BDB(R) \
(FLD_CLR((R)->lockout_flags, (REP_LOCKOUT_API | REP_LOCKOUT_OP)))
/*
* Recovery flag mask to easily check any/all recovery bits. That is
* REP_LOCKOUT_{API|OP} and most REP_S_*. This must change if the values
* of the flags change. NOTE: We do not include REP_LOCKOUT_MSG in
* this mask because it is used frequently in non-recovery related
* areas and we want to manipulate it separately (see especially
* in __rep_new_master).
*/
#define CLR_RECOVERY_SETTINGS(R) \
do { \
(R)->sync_state = SYNC_OFF; \
CLR_LOCKOUT_BDB(R); \
} while (0)
#define IS_REP_RECOVERING(R) \
((R)->sync_state != SYNC_OFF || ISSET_LOCKOUT_BDB(R))
/*
* REP_F_EPHASE0 is not a *real* election phase. It is used for
* master leases and allowing the client to find the master or
* expire its lease. However, EPHASE0 is cleared by __rep_elect_done.
*/
#define IN_ELECTION(R) \
FLD_ISSET((R)->elect_flags, REP_E_PHASE1 | REP_E_PHASE2)
#define IN_ELECTION_TALLY(R) \
FLD_ISSET((R)->elect_flags, REP_E_PHASE1 | REP_E_PHASE2 | REP_E_TALLY)
#define ELECTION_MAJORITY(n) (((n) / 2) + 1)
#define IN_INTERNAL_INIT(R) \
((R)->sync_state == SYNC_LOG || (R)->sync_state == SYNC_PAGE)
#define IS_REP_MASTER(env) \
(REP_ON(env) && \
F_ISSET(((env)->rep_handle->region), REP_F_MASTER))
#define IS_REP_CLIENT(env) \
(REP_ON(env) && \
F_ISSET(((env)->rep_handle->region), REP_F_CLIENT))
#define IS_REP_STARTED(env) \
(REP_ON(env) && \
F_ISSET(((env)->rep_handle->region), REP_F_START_CALLED))
#define IS_USING_LEASES(env) \
(REP_ON(env) && \
FLD_ISSET(((env)->rep_handle->region)->config, REP_C_LEASE))
#define IS_CLIENT_PGRECOVER(env) \
(IS_REP_CLIENT(env) && \
(((env)->rep_handle->region)->sync_state == SYNC_PAGE))
/*
* Macros to figure out if we need to do replication pre/post-amble processing.
* Skip for specific DB handles owned by the replication layer, either because
* replication is running recovery or because it's a handle entirely owned by
* the replication code (replication opens its own databases to track state).
*/
#define REP_FLAGS_SET(env) \
((env)->rep_handle->region->flags != 0 || \
(env)->rep_handle->region->elect_flags != 0 || \
(env)->rep_handle->region->lockout_flags != 0)
#define IS_ENV_REPLICATED(env) \
(REP_ON(env) && REP_FLAGS_SET(env))
/*
* Update the temporary log archive block timer.
*/
#define MASTER_UPDATE(env, renv) do { \
REP_SYSTEM_LOCK(env); \
F_SET((renv), DB_REGENV_REPLOCKED); \
(void)time(&(renv)->op_timestamp); \
REP_SYSTEM_UNLOCK(env); \
} while (0)
/*
* Macro to set a new generation number. Cached values from the LSN history
* database are associated with the current gen, so when the gen changes we must
* invalidate the cache. Use this macro for all gen changes, to avoid
* forgetting to do so. This macro should be used while holding the rep system
* mutex (unless we know we're single-threaded for some other reason, like at
* region create time).
*/
#define SET_GEN(g) do { \
rep->gen = (g); \
ZERO_LSN(rep->gen_base_lsn); \
} while (0)
/*
* Gap processing flags. These provide control over the basic
* gap processing algorithm for some special cases.
*/
#define REP_GAP_FORCE 0x001 /* Force a request for a gap. */
#define REP_GAP_REREQUEST 0x002 /* Gap request is a forced rerequest. */
/* REREQUEST is a superset of FORCE. */
/*
* Flags indicating what kind of record we want to back up to, in the log.
*/
#define REP_REC_COMMIT 0x001 /* Most recent commit record. */
#define REP_REC_PERM 0x002 /* Most recent perm record. */
/* PERM is a superset of COMMIT. */
/*
* Basic pre/post-amble processing.
*/
#define REPLICATION_WRAP(env, func_call, checklock, ret) do { \
int __rep_check, __t_ret; \
__rep_check = IS_ENV_REPLICATED(env) ? 1 : 0; \
(ret) = __rep_check ? __env_rep_enter(env, checklock) : 0; \
if ((ret) == 0) { \
(ret) = func_call; \
if (__rep_check && (__t_ret = \
__env_db_rep_exit(env)) != 0 && (ret) == 0) \
(ret) = __t_ret; \
} \
} while (0)
/*
* Macro to safely access curinfo and its internal DBT pointers from
* any process. This should always be used to access curinfo. If
* the internal DBT pointers are to be used, mtx_clientdb must be held
* between the time of this call and the use of the pointers.
*
* The current file information (curinfo) is stored in shared region
* memory and accessed via an offset. It contains DBTs that themselves
* point to allocated data. __rep_nextfile() manages this information in a
* single chunk of shared memory.
*
* If different processes access curinfo, they may have different shared
* region addresses. This means that curinfo and its pointers to DBT data
* must be recalculated for each process starting with the offset.
*/
#define GET_CURINFO(rep, infop, curinfo) \
do { \
curinfo = R_ADDR(infop, rep->curinfo_off); \
if ((curinfo)->uid.size > 0) \
(curinfo)->uid.data = R_ADDR(infop, \
rep->curinfo_off + sizeof(__rep_fileinfo_args)); \
else \
(curinfo)->uid.data = NULL; \
if ((curinfo)->info.size > 0) \
(curinfo)->info.data = R_ADDR(infop, rep->curinfo_off + \
sizeof(__rep_fileinfo_args) + (curinfo)->uid.size); \
else \
(curinfo)->info.data = NULL; \
if ((curinfo)->dir.size > 0) \
(curinfo)->dir.data = R_ADDR(infop, rep->curinfo_off + \
sizeof(__rep_fileinfo_args) + (curinfo)->uid.size + \
(curinfo)->info.size); \
else \
(curinfo)->dir.data = NULL; \
} while (0)
/*
* Per-process replication structure.
*
* There are 2 mutexes used in the Base replication API. (See LOCK_MUTEX in
* repmgr.h for a discussion of repmgr.)
* 1. mtx_region - This protects the fields of the rep region above.
* 2. mtx_clientdb - This protects the per-process flags, and bookkeeping
* database and all of the components that maintain it. Those
* components include the following fields in the log region (see log.h):
* a. ready_lsn
* b. waiting_lsn
* c. verify_lsn
* d. wait_recs
* e. rcvd_recs
* f. max_wait_lsn
* These fields in the log region are NOT protected by the log region lock at
* all.
*
* Note that the per-process flags should truly be protected by a special
* per-process thread mutex, but it is currently set in so isolated a manner
* that it didn't make sense to do so and in most case we're already holding
* the mtx_clientdb anyway.
*
* The lock ordering protocol is that mtx_clientdb must be acquired first and
* then either REP->mtx_region, or the LOG->mtx_region mutex may be acquired if
* necessary.
*
* Note that the appropriate mutex is needed any time one or more related
* values are read or written that could possibly use more than one atomic
* machine instruction. A single 32-bit integer value is safe without a
* mutex, but most other types of value should use a mutex.
*
* Any use of a mutex must be inside a matched pair of ENV_ENTER() and
* ENV_LEAVE() macros. This ensures that if a thread dies while holding
* a lock (i.e. a mutex), recovery can clean it up so that it does not
* indefinitely block other threads.
*/
struct __db_rep {
/*
* Shared configuration information -- copied to and maintained in the
* shared region as soon as the shared region is created.
*/
int eid; /* Environment ID. */
u_int32_t gbytes; /* Limit on data sent in single... */
u_int32_t bytes; /* __rep_process_message call. */
db_timespec request_gap; /* Minimum time to wait before we
* request a missing log record. */
db_timespec max_gap; /* Maximum time to wait before
* requesting a missing log record. */
u_int32_t clock_skew; /* Clock skew factor. */
u_int32_t clock_base; /* Clock skew base. */
u_int32_t config; /* Configuration flags. */
u_int32_t config_nsites;
db_timeout_t elect_timeout; /* Normal/full election timeouts. */
db_timeout_t full_elect_timeout;
db_timeout_t chkpt_delay; /* Master checkpoint delay. */
u_int32_t my_priority;
db_timeout_t lease_timeout; /* Master leases. */
/*
* End of shared configuration information.
*/
int (*send) /* Send function. */
__P((DB_ENV *, const DBT *, const DBT *,
const DB_LSN *, int, u_int32_t));
DB *rep_db; /* Bookkeeping database. */
DB *lsn_db; /* (Replicated) LSN history database. */
REP *region; /* In memory structure. */
u_int8_t *bulk; /* Shared memory bulk area. */
#define DBREP_DIAG_FILES 2
DB_FH *diagfile[DBREP_DIAG_FILES]; /* Diag files fhp. */
off_t diag_off; /* Current diag file offset. */
/* These are protected by mtx_clientdb. */
DB_MPOOLFILE *file_mpf; /* Mpoolfile for current database. */
DB *file_dbp; /* This file's page info. */
DBC *queue_dbc; /* Dbc for a queue file. */
/*
* Please change __rep_print_all (rep_stat.c) to track any changes made
* to these flags.
*/
#define DBREP_APP_BASEAPI 0x0001 /* Base API application. */
#define DBREP_APP_REPMGR 0x0002 /* repmgr application. */
#define DBREP_OPENFILES 0x0004 /* This handle has opened files. */
u_int32_t flags; /* per-process flags. */
#ifdef HAVE_REPLICATION_THREADS
/*
* Replication Framework (repmgr) per-process information.
*/
u_int nthreads; /* Msg processing threads. */
u_int athreads; /* Space allocated for msg threads. */
u_int non_rep_th; /* Threads in GMDB or channel msgs. */
u_int aelect_threads; /* Space allocated for elect threads. */
u_int32_t init_policy;
int perm_policy;
DB_LSN perm_lsn; /* Last perm LSN we've announced. */
db_timeout_t ack_timeout;
db_timeout_t election_retry_wait;
db_timeout_t connection_retry_wait;
db_timeout_t heartbeat_frequency; /* Max period between msgs. */
db_timeout_t heartbeat_monitor_timeout;
/* Thread synchronization. */
REPMGR_RUNNABLE *selector, **messengers, **elect_threads;
REPMGR_RUNNABLE *preferred_elect_thr;
db_timespec repstart_time;
mgr_mutex_t *mutex;
cond_var_t check_election, gmdb_idle, msg_avail;
waiter_t ack_waiters; /* For threads awaiting PERM acks. */
#ifdef DB_WIN32
HANDLE signaler;
#else
int read_pipe, write_pipe;
#endif
/* Operational stuff. */
REPMGR_SITE *sites; /* Array of known sites. */
u_int site_cnt; /* Array slots in use. */
u_int site_max; /* Total array slots allocated. */
int self_eid; /* Where to find the local site. */
u_int siteinfo_seq; /* Last known update to this list. */
/*
* The connections list contains only those connections not actively
* associated with a known site (see repmgr.h).
*/
CONNECTION_LIST connections;
RETRY_Q_HEADER retries; /* Sites needing connection retry. */
struct {
int size;
STAILQ_HEAD(__repmgr_q_header, __repmgr_message) header;
} input_queue;
socket_t listen_fd;
db_timespec last_bcast; /* Time of last broadcast msg. */
/*
* Status of repmgr. It is ready when repmgr is not yet started. It
* is running after repmgr is (re)started. It is stopped if the env
* of the running repmgr is closed, or the site is removed.
*/
enum { ready, running, stopped } repmgr_status;
int new_connection; /* Since last master seek attempt. */
int takeover_pending; /* We've been elected master. */
int gmdb_busy;
int client_intent; /* Will relinquish master role. */
int gmdb_dirty;
int have_gmdb;
int seen_repmsg;
/*
* Flag to show what kind of transaction is currently in progress.
* Primary means we're doing the first (critical) phase of a membership
* DB update, where we care about perm failures. In the secondary phase
* we don't care. Usually the value is "none", when normal user
* transactions are happening. We need to use this global flag because
* we don't have a more proper direct channel to communicate information
* between the originator of a transaction and the replication send()
* function that has to wait for acks and decide what to do about them.
*/
enum { none, gmdb_primary, gmdb_secondary } active_gmdb_update;
int limbo_resolution_needed;
/*
* GMDB update sequence count. On creation we write version 1; so, once
* repmgr has started and tried to read, a 0 here can be taken to mean
* that the DB doesn't exist yet.
*/
u_int32_t membership_version;
u_int32_t member_version_gen;
/* LSN of GMDB txn that got a perm failure. */
DB_LSN limbo_failure;
/* EID whose membership status is therefore unresolved */
int limbo_victim;
/* LSN of a later txn that achieves perm success. */
DB_LSN durable_lsn;
DB *gmdb; /* Membership database handle. */
/*
* Membership list restored from init file after crash during internal init.
*/
u_int8_t *restored_list;
size_t restored_list_length;
/* Application's message dispatch call-back function. */
void (*msg_dispatch) __P((DB_ENV *, DB_CHANNEL *,
DBT *, u_int32_t, u_int32_t));
#endif /* HAVE_REPLICATION_THREADS */
};
/*
* Determine whether application is repmgr or base replication API. If
* repmgr was configured, base the test on internal replication flags for
* APP_REPMGR and APP_BASEAPI. These flags get set by the appropriate parts
* of the various replication APIs.
*/
#ifdef HAVE_REPLICATION_THREADS
/*
* Application type is set to be repmgr when:
* 1. A local site is defined.
* 2. A remote site is defined.
* 3. An acknowledgement policy is configured.
* 4. A repmgr flag is configured.
* 5. A timeout value is configured for one of the repmgr timeouts.
*/
#define APP_IS_REPMGR(env) \
(REP_ON(env) ? \
F_ISSET((env)->rep_handle->region, REP_F_APP_REPMGR) : \
F_ISSET((env)->rep_handle, DBREP_APP_REPMGR))
/*
* Application type is set to be base replication API when:
* 1. Transport send function is defined and is not the repmgr send
* function.
*/
#define APP_IS_BASEAPI(env) \
(REP_ON(env) ? \
F_ISSET((env)->rep_handle->region, REP_F_APP_BASEAPI) : \
F_ISSET((env)->rep_handle, DBREP_APP_BASEAPI))
/*
* Set application type. These macros do extra checking to guarantee that
* only one application type is ever set.
*/
#define APP_SET_REPMGR(env) do { \
if (REP_ON(env)) { \
ENV_ENTER(env, ip); \
REP_SYSTEM_LOCK(env); \
if (!F_ISSET((env)->rep_handle->region, \
REP_F_APP_BASEAPI)) \
F_SET((env)->rep_handle->region, \
REP_F_APP_REPMGR); \
REP_SYSTEM_UNLOCK(env); \
ENV_LEAVE(env, ip); \
} else if (!F_ISSET((env)->rep_handle, DBREP_APP_BASEAPI)) \
F_SET((env)->rep_handle, DBREP_APP_REPMGR); \
} while (0)
#define APP_SET_BASEAPI(env) do { \
if (REP_ON(env)) { \
ENV_ENTER(env, ip); \
REP_SYSTEM_LOCK(env); \
if (!F_ISSET((env)->rep_handle->region, \
REP_F_APP_REPMGR)) \
F_SET((env)->rep_handle->region, \
REP_F_APP_BASEAPI); \
REP_SYSTEM_UNLOCK(env); \
ENV_LEAVE(env, ip); \
} else if (!F_ISSET((env)->rep_handle, DBREP_APP_REPMGR)) \
F_SET((env)->rep_handle, DBREP_APP_BASEAPI); \
} while (0)
#else
/*
* We did not configure repmgr, application must be base replication API.
* The APP_SET_* macros are noops in this case, but they must be defined
* with a null body to avoid compiler warnings on some platforms.
*/
#define APP_IS_REPMGR(env) 0
#define APP_SET_REPMGR(env) do { \
; \
} while (0)
#define APP_IS_BASEAPI(env) 1
#define APP_SET_BASEAPI(env) do { \
; \
} while (0)
#endif /* HAVE_REPLICATION_THREADS */
/*
* Control structure flags for replication communication infrastructure.
*/
/*
* Define old DB_LOG_ values that we must support here. For reasons of
* compatibility with old versions, these values must be reserved explicitly in
* the list of flag values (below)
*/
#define DB_LOG_PERM_42_44 0x20
#define DB_LOG_RESEND_42_44 0x40
#define REPCTL_INIT_45 0x02 /* Back compatible flag value. */
#define REPCTL_ELECTABLE 0x01 /* Upgraded client is electable. */
#define REPCTL_FLUSH 0x02 /* Record should be flushed. */
#define REPCTL_GROUP_ESTD 0x04 /* Message from site in a group. */
#define REPCTL_INIT 0x08 /* Internal init message. */
#define REPCTL_LEASE 0x10 /* Lease related message.. */
/*
* Skip over reserved values 0x20
* and 0x40, as explained above.
*/
#define REPCTL_LOG_END 0x80 /* Approximate end of group-wide log. */
#define REPCTL_PERM DB_LOG_PERM_42_44
#define REPCTL_RESEND DB_LOG_RESEND_42_44
/*
* File info flags for internal init. The per-database (i.e., file) flag
* represents the on-disk format of the file, and is conveyed from the master to
* the initializing client in the UPDATE message, so that the client can know
* how to create the file. The per-page flag is conveyed along with each PAGE
* message, describing the format of the page image being transmitted; it is of
* course set by the site serving the PAGE_REQ. The serving site gets the page
* image from its own mpool, and thus the page is in the native format of the
* serving site. This format may be different (i.e., opposite) from the on-disk
* format, and in fact can vary per-page, since with client-to-client sync it is
* possible for various different sites to serve the various PAGE_REQ requests.
*/
#define REPINFO_DB_LITTLEENDIAN 0x0001 /* File is little-endian lorder. */
#define REPINFO_PG_LITTLEENDIAN 0x0002 /* Page is little-endian lorder. */
/*
* Control message format for 4.6 release. The db_timespec_t is
* not a portable structure. Therefore, in 4.6, replication among
* mixed OSs such as Linux and Windows, which have different time_t
* sizes, does not work.
*/
typedef struct {
u_int32_t rep_version; /* Replication version number. */
u_int32_t log_version; /* Log version number. */
DB_LSN lsn; /* Log sequence number. */
u_int32_t rectype; /* Message type. */
u_int32_t gen; /* Generation number. */
db_timespec msg_time; /* Timestamp seconds for leases. */
u_int32_t flags; /* log_put flag value. */
} REP_46_CONTROL;
/*
* Control message format for 4.5 release and earlier.
*/
typedef struct {
u_int32_t rep_version; /* Replication version number. */
u_int32_t log_version; /* Log version number. */
DB_LSN lsn; /* Log sequence number. */
u_int32_t rectype; /* Message type. */
u_int32_t gen; /* Generation number. */
u_int32_t flags; /* log_put flag value. */
} REP_OLD_CONTROL;
#define LEASE_REFRESH_MIN 30 /* Minimum number of refresh retries. */
#define LEASE_REFRESH_USEC 50000 /* Microseconds between refresh tries. */
/* Master granted lease information. */
typedef struct __rep_lease_entry {
int eid; /* EID of client grantor. */
db_timespec start_time; /* Start time clients echo back. */
db_timespec end_time; /* Master lease expiration time. */
DB_LSN lease_lsn; /* Durable LSN lease applies to. */
} REP_LEASE_ENTRY;
/*
* Old vote info where some fields were not fixed size.
*/
typedef struct {
u_int32_t egen; /* Election generation. */
int nsites; /* Number of sites I've been in
* communication with. */
int nvotes; /* Number of votes needed to win. */
int priority; /* My site's priority. */
u_int32_t tiebreaker; /* Tie-breaking quasi-random value. */
} REP_OLD_VOTE_INFO;
typedef struct {
u_int32_t egen; /* Voter's election generation. */
int eid; /* Voter's ID. */
} REP_VTALLY;
/*
* The REP_THROTTLE_ONLY flag is used to do throttle processing only.
* If set, it will only allow sending the REP_*_MORE message, but not
* the normal, non-throttled message. It is used to support throttling
* with bulk transfer.
*/
/* Flags for __rep_send_throttle. */
#define REP_THROTTLE_ONLY 0x0001 /* Send _MORE message only. */
/* Throttled message processing information. */
typedef struct {
DB_LSN lsn; /* LSN of this record. */
DBT *data_dbt; /* DBT of this record. */
u_int32_t gbytes; /* This call's max gbytes sent. */
u_int32_t bytes; /* This call's max bytes sent. */
u_int32_t type; /* Record type. */
} REP_THROTTLE;
/* Bulk processing information. */
/*
* !!!
* We use a roff_t for the offset. We'd really like to use a ptrdiff_t
* since that really is what it is. But ptrdiff_t is not portable and
* doesn't exist everywhere.
*/
typedef struct {
u_int8_t *addr; /* Address of bulk buffer. */
roff_t *offp; /* Ptr to current offset into buffer. */
u_int32_t len; /* Bulk buffer length. */
u_int32_t type; /* Item type in buffer (log, page). */
DB_LSN lsn; /* First LSN in buffer. */
int eid; /* ID of potential recipients. */
#define BULK_XMIT 0x001 /* Buffer in transit. */
u_int32_t *flagsp; /* Buffer flags. */
} REP_BULK;
/*
* This structure takes care of representing a transaction.
* It holds all the records, sorted by page number so that
* we can obtain locks and apply updates in a deadlock free
* order.
*/
typedef struct {
u_int nlsns;
u_int nalloc;
DB_LSN *array;
} LSN_COLLECTION;
/*
* This is used by the page-prep routines to do the lock_vec call to
* apply the updates for a single transaction or a collection of
* transactions.
*/
typedef struct {
int n;
DB_LOCKREQ *reqs;
DBT *objs;
} linfo_t;
#if defined(__cplusplus)
}
#endif
#include "dbinc_auto/rep_ext.h"
#endif /* !_DB_REP_H_ */
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