~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifndef DRIZZLE_SERVER_SLAVE_H

#define DRIZZLE_SERVER_SLAVE_H

/**

  @defgroup Replication Replication

  @{

  @file

*/

/** 

   Some of defines are need in parser even though replication is not 

   compiled in (embedded).

*/

#include "log.h"

#include <mysys/my_list.h>

#include "rpl_filter.h"

#include "rpl_tblmap.h"

// 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, session

  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 (DRIZZLE_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 DRIZZLE_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 uint32_t master_retry_count;

extern MY_BITMAP slave_error_mask;

extern bool use_slave_mask;

extern char *slave_load_tmpdir;

extern char *master_info_file, *relay_log_info_file;

extern char *opt_relay_logname, *opt_relaylog_index_name;

extern bool opt_skip_slave_start;

extern bool opt_reckless_slave;

extern bool opt_log_slave_updates;

extern uint64_t 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 DRIZZLE_SLAVE_NOT_RUN         0

#define DRIZZLE_SLAVE_RUN_NOT_CONNECT 1

#define DRIZZLE_SLAVE_RUN_CONNECT     2

#define RPL_LOG_NAME (rli->group_master_log_name.length() ? rli->group_master_log_name.c_str() : "FIRST")

#define IO_RPL_LOG_NAME (mi->getLogName() ? mi->getLogName() : "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

int32_t init_slave();

void init_slave_skip_errors(const char* arg);

bool flush_relay_log_info(Relay_log_info* rli);

int32_t register_slave_on_master(DRIZZLE *drizzle);

int32_t terminate_slave_threads(Master_info* mi, int32_t thread_mask,

			     bool skip_lock = 0);

int32_t start_slave_threads(bool need_slave_mutex, bool wait_for_start,

			Master_info* mi, const char* master_info_fname,

			const char* slave_info_fname, int32_t 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

*/

int32_t start_slave_thread(pthread_handler h_func, pthread_mutex_t* start_lock,

		       pthread_mutex_t *cond_lock,

		       pthread_cond_t* start_cond,

		       volatile uint32_t *slave_running,

		       volatile uint32_t *slave_run_id,

		       Master_info* mi,

                       bool high_priority);

/* If fd is -1, dump to NET */

int32_t mysql_table_dump(Session* session, const char* db,

		     const char* tbl_name, int32_t fd = -1);

/* retrieve table from master and copy to slave*/

int32_t fetch_master_table(Session* session, const char* db_name, const char* table_name,

		       Master_info* mi, DRIZZLE *drizzle, bool overwrite);

bool show_master_info(Session* session, Master_info* mi);

bool show_binlog_info(Session* session);

bool rpl_master_has_bug(Relay_log_info *rli, uint32_t bug_id, bool report= true);

bool rpl_master_erroneous_autoinc(Session* session);

const char *print_slave_db_safe(const char *db);

int32_t check_expected_error(Session* session, Relay_log_info const *rli, int32_t error_code);

void skip_load_data_infile(NET* net);

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(int32_t* mask,Master_info* mi,bool inverse);

int32_t init_relay_log_pos(Relay_log_info* rli,const char* log,uint64_t pos,

		       bool need_data_lock, const char** errmsg,

                       bool look_for_description_event);

int32_t purge_relay_logs(Relay_log_info* rli, Session *session, bool just_reset,

		     const char** errmsg);

void set_slave_thread_options(Session* session);

void rotate_relay_log(Master_info* mi);

int32_t apply_event_and_update_pos(Log_event* ev, Session* session, Relay_log_info* rli,

                               bool skip);

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 bool replicate_same_server_id;

extern int32_t disconnect_slave_event_count, abort_slave_event_count ;

/* the master variables are defaults read from drizzle.cnf or command line */

extern uint32_t master_port, master_connect_retry, report_port;

extern char * master_user, *master_password, *master_host;

extern char *master_info_file, *relay_log_info_file, *report_user;

extern char *report_host, *report_password;

extern 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<Session> threads;

/**

  @} (end of group Replication)

*/

#endif /* DRIZZLE_SERVER_SLAVE_H */