/* Copyright (C) 2000-2003 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef SLAVE_H #define SLAVE_H /** @defgroup Replication Replication @{ @file */ #ifdef HAVE_REPLICATION #include "log.h" #include "my_list.h" #include "rpl_filter.h" #include "rpl_tblmap.h" #define SLAVE_NET_TIMEOUT 3600 #define MAX_SLAVE_ERROR 2000 // Forward declarations class Relay_log_info; class Master_info; /***************************************************************************** MySQL Replication Replication is implemented via two types of threads: I/O Thread - One of these threads is started for each master server. They maintain a connection to their master server, read log events from the master as they arrive, and queues them into a single, shared relay log file. A Master_info represents each of these threads. SQL Thread - One of these threads is started and reads from the relay log file, executing each event. A Relay_log_info represents this thread. Buffering in the relay log file makes it unnecessary to reread events from a master server across a slave restart. It also decouples the slave from the master where long-running updates and event logging are concerned--ie it can continue to log new events while a slow query executes on the slave. *****************************************************************************/ /* MUTEXES in replication: LOCK_active_mi: [note: this was originally meant for multimaster, to switch from a master to another, to protect active_mi] It is used to SERIALIZE ALL administrative commands of replication: START SLAVE, STOP SLAVE, CHANGE MASTER, RESET SLAVE, end_slave() (when mysqld stops) [init_slave() does not need it it's called early]. Any of these commands holds the mutex from the start till the end. This thus protects us against a handful of deadlocks (consider start_slave_thread() which, when starting the I/O thread, releases mi->run_lock, keeps rli->run_lock, and tries to re-acquire mi->run_lock). Currently active_mi never moves (it's created at startup and deleted at shutdown, and not changed: it always points to the same Master_info struct), because we don't have multimaster. So for the moment, mi does not move, and mi->rli does not either. In Master_info: run_lock, data_lock run_lock protects all information about the run state: slave_running, thd and the existence of the I/O thread to stop/start it, you need this mutex). data_lock protects some moving members of the struct: counters (log name, position) and relay log (MYSQL_BIN_LOG object). In Relay_log_info: run_lock, data_lock see Master_info Order of acquisition: if you want to have LOCK_active_mi and a run_lock, you must acquire LOCK_active_mi first. In MYSQL_BIN_LOG: LOCK_log, LOCK_index of the binlog and the relay log LOCK_log: when you write to it. LOCK_index: when you create/delete a binlog (so that you have to update the .index file). */ extern ulong master_retry_count; extern MY_BITMAP slave_error_mask; extern char slave_skip_error_names[]; extern bool use_slave_mask; extern char *slave_load_tmpdir; extern char *master_info_file; extern MYSQL_PLUGIN_IMPORT char *relay_log_info_file; extern char *opt_relay_logname, *opt_relaylog_index_name; extern my_bool opt_skip_slave_start, opt_reckless_slave; extern my_bool opt_log_slave_updates; extern ulonglong relay_log_space_limit; /* 3 possible values for Master_info::slave_running and Relay_log_info::slave_running. The values 0,1,2 are very important: to keep the diff small, I didn't substitute places where we use 0/1 with the newly defined symbols. So don't change these values. The same way, code is assuming that in Relay_log_info we use only values 0/1. I started with using an enum, but enum_variable=1; is not legal so would have required many line changes. */ #define MYSQL_SLAVE_NOT_RUN 0 #define MYSQL_SLAVE_RUN_NOT_CONNECT 1 #define MYSQL_SLAVE_RUN_CONNECT 2 #define RPL_LOG_NAME (rli->group_master_log_name[0] ? rli->group_master_log_name :\ "FIRST") #define IO_RPL_LOG_NAME (mi->master_log_name[0] ? mi->master_log_name :\ "FIRST") /* If the following is set, if first gives an error, second will be tried. Otherwise, if first fails, we fail. */ #define SLAVE_FORCE_ALL 4 int init_slave(); void init_slave_skip_errors(const char* arg); bool flush_relay_log_info(Relay_log_info* rli); int register_slave_on_master(MYSQL* mysql); int terminate_slave_threads(Master_info* mi, int thread_mask, bool skip_lock = 0); int start_slave_threads(bool need_slave_mutex, bool wait_for_start, Master_info* mi, const char* master_info_fname, const char* slave_info_fname, int thread_mask); /* cond_lock is usually same as start_lock. It is needed for the case when start_lock is 0 which happens if start_slave_thread() is called already inside the start_lock section, but at the same time we want a pthread_cond_wait() on start_cond,start_lock */ int start_slave_thread(pthread_handler h_func, pthread_mutex_t* start_lock, pthread_mutex_t *cond_lock, pthread_cond_t* start_cond, volatile uint *slave_running, volatile ulong *slave_run_id, Master_info* mi, bool high_priority); /* If fd is -1, dump to NET */ int mysql_table_dump(THD* thd, const char* db, const char* tbl_name, int fd = -1); /* retrieve table from master and copy to slave*/ int fetch_master_table(THD* thd, const char* db_name, const char* table_name, Master_info* mi, MYSQL* mysql, bool overwrite); bool show_master_info(THD* thd, Master_info* mi); bool show_binlog_info(THD* thd); bool rpl_master_has_bug(const Relay_log_info *rli, uint bug_id, bool report, bool (*pred)(const void *), const void *param); bool rpl_master_erroneous_autoinc(THD* thd); const char *print_slave_db_safe(const char *db); void skip_load_data_infile(NET* net); void end_slave(); /* release slave threads */ void close_active_mi(); /* clean up slave threads data */ void clear_until_condition(Relay_log_info* rli); void clear_slave_error(Relay_log_info* rli); void end_relay_log_info(Relay_log_info* rli); void lock_slave_threads(Master_info* mi); void unlock_slave_threads(Master_info* mi); void init_thread_mask(int* mask,Master_info* mi,bool inverse); int init_relay_log_pos(Relay_log_info* rli,const char* log,ulonglong pos, bool need_data_lock, const char** errmsg, bool look_for_description_event); int purge_relay_logs(Relay_log_info* rli, THD *thd, bool just_reset, const char** errmsg); void set_slave_thread_options(THD* thd); void set_slave_thread_default_charset(THD *thd, Relay_log_info const *rli); int rotate_relay_log(Master_info* mi); int apply_event_and_update_pos(Log_event* ev, THD* thd, Relay_log_info* rli); pthread_handler_t handle_slave_io(void *arg); pthread_handler_t handle_slave_sql(void *arg); extern bool volatile abort_loop; extern Master_info main_mi, *active_mi; /* active_mi for multi-master */ extern LIST master_list; extern my_bool replicate_same_server_id; extern int disconnect_slave_event_count, abort_slave_event_count ; /* the master variables are defaults read from my.cnf or command line */ extern uint master_port, master_connect_retry, report_port; extern char * master_user, *master_password, *master_host; extern char *master_info_file, *report_user; extern char *report_host, *report_password; extern my_bool master_ssl; extern char *master_ssl_ca, *master_ssl_capath, *master_ssl_cert; extern char *master_ssl_cipher, *master_ssl_key; extern I_List threads; #endif /* HAVE_REPLICATION */ /* masks for start/stop operations on io and sql slave threads */ #define SLAVE_IO 1 #define SLAVE_SQL 2 /** @} (end of group Replication) */ #endif