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/* 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
#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
struct st_relay_log_info;
typedef st_relay_log_info 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, 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 bool use_slave_mask;
extern char* slave_load_tmpdir;
extern my_string master_info_file,relay_log_info_file;
extern my_string 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 terminate_slave_thread(THD* thd, pthread_mutex_t* term_mutex,
pthread_mutex_t* cond_lock,
pthread_cond_t* term_cond,
volatile uint* slave_running);
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(RELAY_LOG_INFO *rli, uint bug_id);
const char *print_slave_db_safe(const char *db);
int check_expected_error(THD* thd, RELAY_LOG_INFO const *rli, int error_code);
void skip_load_data_infile(NET* net);
void slave_print_msg(enum loglevel level, RELAY_LOG_INFO const *rli,
int err_code, const char* msg, ...)
ATTRIBUTE_FORMAT(printf, 4, 5);
void end_slave(); /* clean up */
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);
void rotate_relay_log(MASTER_INFO* mi);
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 my_string master_user, master_password, master_host,
master_info_file, relay_log_info_file, report_user, report_host,
report_password;
extern my_bool master_ssl;
extern my_string master_ssl_ca, master_ssl_capath, master_ssl_cert,
master_ssl_cipher, master_ssl_key;
extern I_List<THD> threads;
#endif /* HAVE_REPLICATION */
/* masks for start/stop operations on io and sql slave threads */
#define SLAVE_IO 1
#define SLAVE_SQL 2
#endif
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