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/* Copyright (C) 2000-2003 MySQL AB
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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@defgroup Replication Replication
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Some of defines are need in parser even though replication is not
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compiled in (embedded).
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The maximum is defined as (ULONG_MAX/1000) with 4 bytes ulong
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#define SLAVE_MAX_HEARTBEAT_PERIOD 4294967
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#ifdef HAVE_REPLICATION
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#include "rpl_filter.h"
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#include "rpl_tblmap.h"
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#define SLAVE_NET_TIMEOUT 3600
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#define MAX_SLAVE_ERROR 2000
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// Forward declarations
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/*****************************************************************************
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Replication is implemented via two types of threads:
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I/O Thread - One of these threads is started for each master server.
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They maintain a connection to their master server, read log
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events from the master as they arrive, and queues them into
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a single, shared relay log file. A Master_info
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represents each of these threads.
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SQL Thread - One of these threads is started and reads from the relay log
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file, executing each event. A Relay_log_info
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represents this thread.
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Buffering in the relay log file makes it unnecessary to reread events from
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a master server across a slave restart. It also decouples the slave from
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the master where long-running updates and event logging are concerned--ie
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it can continue to log new events while a slow query executes on the slave.
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*****************************************************************************/
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MUTEXES in replication:
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LOCK_active_mi: [note: this was originally meant for multimaster, to switch
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from a master to another, to protect active_mi] It is used to SERIALIZE ALL
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administrative commands of replication: START SLAVE, STOP SLAVE, CHANGE
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MASTER, RESET SLAVE, end_slave() (when mysqld stops) [init_slave() does not
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need it it's called early]. Any of these commands holds the mutex from the
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start till the end. This thus protects us against a handful of deadlocks
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(consider start_slave_thread() which, when starting the I/O thread, releases
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mi->run_lock, keeps rli->run_lock, and tries to re-acquire mi->run_lock).
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Currently active_mi never moves (it's created at startup and deleted at
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shutdown, and not changed: it always points to the same Master_info struct),
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because we don't have multimaster. So for the moment, mi does not move, and
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mi->rli does not either.
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In Master_info: run_lock, data_lock
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run_lock protects all information about the run state: slave_running, thd
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and the existence of the I/O thread to stop/start it, you need this mutex).
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data_lock protects some moving members of the struct: counters (log name,
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position) and relay log (MYSQL_BIN_LOG object).
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In Relay_log_info: run_lock, data_lock
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Order of acquisition: if you want to have LOCK_active_mi and a run_lock, you
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must acquire LOCK_active_mi first.
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In MYSQL_BIN_LOG: LOCK_log, LOCK_index of the binlog and the relay log
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LOCK_log: when you write to it. LOCK_index: when you create/delete a binlog
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(so that you have to update the .index file).
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extern ulong master_retry_count;
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extern MY_BITMAP slave_error_mask;
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extern bool use_slave_mask;
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extern char *slave_load_tmpdir;
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extern char *master_info_file, *relay_log_info_file;
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extern char *opt_relay_logname, *opt_relaylog_index_name;
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extern my_bool opt_skip_slave_start, opt_reckless_slave;
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extern my_bool opt_log_slave_updates;
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extern ulonglong relay_log_space_limit;
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3 possible values for Master_info::slave_running and
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Relay_log_info::slave_running.
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The values 0,1,2 are very important: to keep the diff small, I didn't
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substitute places where we use 0/1 with the newly defined symbols. So don't change
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The same way, code is assuming that in Relay_log_info we use only values
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I started with using an enum, but
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enum_variable=1; is not legal so would have required many line changes.
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#define MYSQL_SLAVE_NOT_RUN 0
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#define MYSQL_SLAVE_RUN_NOT_CONNECT 1
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#define MYSQL_SLAVE_RUN_CONNECT 2
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#define RPL_LOG_NAME (rli->group_master_log_name[0] ? rli->group_master_log_name :\
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#define IO_RPL_LOG_NAME (mi->master_log_name[0] ? mi->master_log_name :\
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If the following is set, if first gives an error, second will be
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tried. Otherwise, if first fails, we fail.
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#define SLAVE_FORCE_ALL 4
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void init_slave_skip_errors(const char* arg);
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bool flush_relay_log_info(Relay_log_info* rli);
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int register_slave_on_master(MYSQL* mysql);
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int terminate_slave_threads(Master_info* mi, int thread_mask,
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int start_slave_threads(bool need_slave_mutex, bool wait_for_start,
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Master_info* mi, const char* master_info_fname,
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const char* slave_info_fname, int thread_mask);
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cond_lock is usually same as start_lock. It is needed for the case when
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start_lock is 0 which happens if start_slave_thread() is called already
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inside the start_lock section, but at the same time we want a
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pthread_cond_wait() on start_cond,start_lock
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int start_slave_thread(pthread_handler h_func, pthread_mutex_t* start_lock,
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pthread_mutex_t *cond_lock,
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pthread_cond_t* start_cond,
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volatile uint *slave_running,
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volatile ulong *slave_run_id,
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/* If fd is -1, dump to NET */
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int mysql_table_dump(THD* thd, const char* db,
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const char* tbl_name, int fd = -1);
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/* retrieve table from master and copy to slave*/
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int fetch_master_table(THD* thd, const char* db_name, const char* table_name,
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Master_info* mi, MYSQL* mysql, bool overwrite);
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bool show_master_info(THD* thd, Master_info* mi);
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bool show_binlog_info(THD* thd);
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bool rpl_master_has_bug(Relay_log_info *rli, uint bug_id, bool report=TRUE);
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bool rpl_master_erroneous_autoinc(THD* thd);
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const char *print_slave_db_safe(const char *db);
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int check_expected_error(THD* thd, Relay_log_info const *rli, int error_code);
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void skip_load_data_infile(NET* net);
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void end_slave(); /* clean up */
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void clear_until_condition(Relay_log_info* rli);
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void clear_slave_error(Relay_log_info* rli);
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void end_relay_log_info(Relay_log_info* rli);
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void lock_slave_threads(Master_info* mi);
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void unlock_slave_threads(Master_info* mi);
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void init_thread_mask(int* mask,Master_info* mi,bool inverse);
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int init_relay_log_pos(Relay_log_info* rli,const char* log,ulonglong pos,
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bool need_data_lock, const char** errmsg,
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bool look_for_description_event);
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int purge_relay_logs(Relay_log_info* rli, THD *thd, bool just_reset,
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const char** errmsg);
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void set_slave_thread_options(THD* thd);
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void set_slave_thread_default_charset(THD *thd, Relay_log_info const *rli);
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void rotate_relay_log(Master_info* mi);
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int apply_event_and_update_pos(Log_event* ev, THD* thd, Relay_log_info* rli,
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pthread_handler_t handle_slave_io(void *arg);
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pthread_handler_t handle_slave_sql(void *arg);
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extern bool volatile abort_loop;
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extern Master_info main_mi, *active_mi; /* active_mi for multi-master */
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extern LIST master_list;
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extern my_bool replicate_same_server_id;
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extern int disconnect_slave_event_count, abort_slave_event_count ;
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/* the master variables are defaults read from my.cnf or command line */
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extern uint master_port, master_connect_retry, report_port;
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extern char * master_user, *master_password, *master_host;
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extern char *master_info_file, *relay_log_info_file, *report_user;
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extern char *report_host, *report_password;
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extern my_bool master_ssl;
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extern char *master_ssl_ca, *master_ssl_capath, *master_ssl_cert;
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extern char *master_ssl_cipher, *master_ssl_key;
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extern I_List<THD> threads;
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#endif /* HAVE_REPLICATION */
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/* masks for start/stop operations on io and sql slave threads */
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@} (end of group Replication)
added
removed
sql/slave.h
