packages/mysql5
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
mysql5/mysql-5.7.27/sql/rpl_slave.h

469 lines
17 KiB
C++
Raw Blame History

/* Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
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,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */
#ifndef RPL_SLAVE_H
#define RPL_SLAVE_H
#include "my_global.h"
#include "my_thread.h" // my_start_routine
#include "mysql/psi/mysql_thread.h" // mysql_mutex_t
#include "rpl_channel_service_interface.h" // enum_channel_type
class Log_event;
class Master_info;
class Relay_log_info;
class THD;
typedef struct st_bitmap MY_BITMAP;
typedef struct st_lex_master_info LEX_MASTER_INFO;
typedef struct st_list LIST;
typedef struct st_mysql MYSQL;
typedef struct st_net NET;
typedef struct struct_slave_connection LEX_SLAVE_CONNECTION;
typedef enum { SLAVE_THD_IO, SLAVE_THD_SQL, SLAVE_THD_WORKER } SLAVE_THD_TYPE;
/**
MASTER_DELAY can be at most (1 << 31) - 1.
*/
#define MASTER_DELAY_MAX (0x7FFFFFFF)
#if INT_MAX < 0x7FFFFFFF
#error "don't support platforms where INT_MAX < 0x7FFFFFFF"
#endif
/**
@defgroup Replication Replication
@{
@file
*/
/**
Some of defines are need in parser even though replication is not
compiled in (embedded).
*/
/**
The maximum is defined as (ULONG_MAX/1000) with 4 bytes ulong
*/
#define SLAVE_MAX_HEARTBEAT_PERIOD 4294967
#ifdef HAVE_REPLICATION
#define SLAVE_NET_TIMEOUT 60
#define MAX_SLAVE_ERROR 10000
#define MTS_WORKER_UNDEF ((ulong) -1)
#define MTS_MAX_WORKERS 1024
#define MAX_SLAVE_RETRY_PAUSE 5
/*
When using tables to store the slave workers bitmaps,
we use a BLOB field. The maximum size of a BLOB is:
2^16-1 = 65535 bytes => (2^16-1) * 8 = 524280 bits
*/
#define MTS_MAX_BITS_IN_GROUP ((1L << 19) - 8) /* 524280 */
extern bool server_id_supplied;
/*****************************************************************************
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:
m_channel_map_lock: This rwlock is used to protect the multi source
replication data structure (channel_map). Any operation reading contents
from the channel_map should hold the rdlock during the operation. Any
operation changing the channel_map (either adding/removing channels to/from
the channel_map) should hold the wrlock during the operation.
[init_slave() does not need it it's called early].
In Master_info: m_channel_lock
It is used to SERIALIZE ALL administrative commands of replication: START
SLAVE, STOP SLAVE, CHANGE MASTER, RESET SLAVE, delete_slave_info_objects
(when mysqld stops)
This thus protects us against a handful of deadlocks, being the know ones
around lock_slave_threads and the mixed order they are acquired in some
operations:
+ 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.
+ Same applies to stop_slave() where a stop of the I/O thread will
mi->run_lock, keeps rli->run_lock, and tries to re-acquire mi->run_lock.
For the SQL thread, the order is the opposite.
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).
Check the above m_channel_lock about locking order.
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, also the above m_channel_lock about locking order.
However, note that run_lock does not protect Relay_log_info.run_state;
that is protected by data_lock.
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).
The global_sid_lock must not be taken after LOCK_reset_gtid_table.
==== Order of acquisition ====
Here, we list most major functions that acquire multiple locks.
Notation: For each function, we list the locks it takes, in the
order it takes them. If a function holds lock A while taking lock
B, then we write "A, B". If a function locks A, unlocks A, then
locks B, then we write "A | B". If function F1 invokes function F2,
then we write F2's name in parentheses in the list of locks for F1.
show_master_info:
mi.data_lock, rli.data_lock, mi.err_lock, rli.err_lock
stop_slave:
channel_map lock,
( mi.channel_wrlock, mi.run_lock, thd.LOCK_thd_data
| rli.run_lock, thd.LOCK_thd_data
| relay.LOCK_log
)
start_slave:
mi.channel_wrlock, mi.run_lock, rli.run_lock, rli.data_lock, global_sid_lock->wrlock
reset_logs:
THD::LOCK_thd_data, .LOCK_log, .LOCK_index, global_sid_lock->wrlock
purge_relay_logs:
rli.data_lock, (relay.reset_logs) THD::LOCK_thd_data,
relay.LOCK_log, relay.LOCK_index, global_sid_lock->wrlock
reset_master:
(binlog.reset_logs) THD::LOCK_thd_data, binlog.LOCK_log,
binlog.LOCK_index, global_sid_lock->wrlock, LOCK_reset_gtid_table
reset_slave:
mi.channel_wrlock, mi.run_lock, rli.run_lock, (purge_relay_logs) rli.data_lock,
THD::LOCK_thd_data, relay.LOCK_log, relay.LOCK_index,
global_sid_lock->wrlock
purge_logs:
.LOCK_index, LOCK_thd_list, thd.linfo.lock
[Note: purge_logs contains a known bug: LOCK_index should not be
taken before LOCK_thd_list. This implies that, e.g.,
purge_master_logs can deadlock with reset_master. However,
although purge_first_log and reset_slave take locks in reverse
order, they cannot deadlock because they both first acquire
rli.data_lock.]
purge_master_logs, purge_master_logs_before_date, purge:
(binlog.purge_logs) binlog.LOCK_index, LOCK_thd_list, thd.linfo.lock
purge_first_log:
rli.data_lock, relay.LOCK_index, rli.log_space_lock,
(relay.purge_logs) LOCK_thd_list, thd.linfo.lock
MYSQL_BIN_LOG::new_file_impl:
.LOCK_log, .LOCK_index,
( [ if binlog: LOCK_prep_xids ]
| global_sid_lock->wrlock
)
rotate_relay_log:
(relay.new_file_impl) relay.LOCK_log, relay.LOCK_index,
global_sid_lock->wrlock
kill_zombie_dump_threads:
LOCK_thd_list, thd.LOCK_thd_data
init_relay_log_pos:
rli.data_lock, relay.log_lock
rli_init_info:
rli.data_lock,
( relay.log_lock
| global_sid_lock->wrlock
| (relay.open_binlog)
| (init_relay_log_pos) rli.data_lock, relay.log_lock
)
change_master:
mi.channel_wrlock, mi.run_lock, rli.run_lock, (init_relay_log_pos) rli.data_lock,
relay.log_lock
Sys_var_gtid_mode::global_update:
gtid_mode_lock, channel_map lock, binlog.LOCK_log, global_sid_lock
So the DAG of lock acquisition order (not counting the buggy
purge_logs) is, empirically:
gtid_mode_lock, channel_map lock, mi.run_lock, rli.run_lock,
( rli.data_lock,
( LOCK_thd_list,
(
( binlog.LOCK_log, binlog.LOCK_index
| relay.LOCK_log, relay.LOCK_index
),
( rli.log_space_lock | global_sid_lock->wrlock )
| binlog.LOCK_log, binlog.LOCK_index, LOCK_prep_xids
| thd.LOCK_data
)
| mi.err_lock, rli.err_lock
)
)
)
| mi.data_lock, rli.data_lock
*/
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, *relay_log_info_file;
extern char *opt_relay_logname, *opt_relaylog_index_name;
extern char *opt_binlog_index_name;
extern my_bool opt_skip_slave_start, opt_reckless_slave;
extern my_bool opt_log_slave_updates;
extern char *opt_slave_skip_errors;
extern ulonglong relay_log_space_limit;
extern const char *relay_log_index;
extern const char *relay_log_basename;
/*
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
/*
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
/* @todo: see if you can change to int */
bool start_slave_cmd(THD* thd);
bool stop_slave_cmd(THD* thd);
bool change_master_cmd(THD *thd);
int change_master(THD* thd, Master_info* mi, LEX_MASTER_INFO* lex_mi,
bool preserve_logs= false);
bool reset_slave_cmd(THD *thd);
bool show_slave_status_cmd(THD *thd);
bool flush_relay_logs_cmd(THD *thd);
bool is_any_slave_channel_running(int thread_mask,
Master_info* already_locked_mi=NULL);
bool flush_relay_logs(Master_info *mi);
int reset_slave(THD *thd, Master_info* mi, bool reset_all);
int reset_slave(THD *thd);
int init_slave();
int init_recovery(Master_info* mi, const char** errmsg);
/**
Call mi->init_info() and/or mi->rli->init_info(), which will read
the replication configuration from repositories.
This takes care of creating a transaction context in case table
repository is needed.
@param mi The Master_info object to use.
@param ignore_if_no_info If this is false, and the repository does
not exist, it will be created. If this is true, and the repository
does not exist, nothing is done.
@param thread_mask Indicate which repositories will be initialized:
if (thread_mask&SLAVE_IO)!=0, then mi->init_info is called; if
(thread_mask&SLAVE_SQL)!=0, then mi->rli->init_info is called.
@retval 0 Success
@retval nonzero Error
*/
int load_mi_and_rli_from_repositories(Master_info* mi,
bool ignore_if_no_info,
int thread_mask);
void end_info(Master_info* mi);
int remove_info(Master_info* mi);
int flush_master_info(Master_info* mi, bool force);
void add_slave_skip_errors(const char* arg);
void set_slave_skip_errors(char** slave_skip_errors_ptr);
int register_slave_on_master(MYSQL* mysql);
int add_new_channel(Master_info** mi, const char* channel);
/**
Terminates the slave threads according to the given mask.
@param mi the master info repository
@param thread_mask the mask identifying which thread(s) to terminate
@param stop_wait_timeout the timeout after which the method returns and error
@param need_lock_term
If @c false the lock will not be acquired before waiting on
the condition. In this case, it is assumed that the calling
function acquires the lock before calling this function.
@return the operation status
@retval 0 OK
@retval ER_SLAVE_NOT_RUNNING
The slave is already stopped
@retval ER_STOP_SLAVE_SQL_THREAD_TIMEOUT
There was a timeout when stopping the SQL thread
@retval ER_STOP_SLAVE_IO_THREAD_TIMEOUT
There was a timeout when stopping the IO thread
@retval ER_ERROR_DURING_FLUSH_LOGS
There was an error while flushing the log/repositories
*/
int terminate_slave_threads(Master_info* mi, int thread_mask,
ulong stop_wait_timeout,
bool need_lock_term= true);
bool start_slave_threads(bool need_lock_slave, bool wait_for_start,
Master_info* mi, int thread_mask);
bool start_slave(THD *thd);
int stop_slave(THD *thd);
bool start_slave(THD* thd,
LEX_SLAVE_CONNECTION* connection_param,
LEX_MASTER_INFO* master_param,
int thread_mask_input,
Master_info* mi,
bool set_mts_settings);
int stop_slave(THD* thd, Master_info* mi, bool net_report,
bool for_one_channel,
bool* push_temp_table_warning);
/*
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
mysql_cond_wait() on start_cond, start_lock
*/
bool start_slave_thread(
#ifdef HAVE_PSI_INTERFACE
PSI_thread_key thread_key,
#endif
my_start_routine h_func,
mysql_mutex_t *start_lock,
mysql_mutex_t *cond_lock,
mysql_cond_t *start_cond,
volatile uint *slave_running,
volatile ulong *slave_run_id,
Master_info *mi);
/* 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_slave_status(THD* thd, Master_info* mi);
bool show_slave_status(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 delete_slave_info_objects(); /* clean up slave threads data */
void clear_until_condition(Relay_log_info* rli);
void clear_slave_error(Relay_log_info* rli);
/**
This method locks both (in this order)
mi->run_lock
rli->run_lock
@param mi The associated master info object
@note this method shall be invoked while locking mi->m_channel_lock
for writes. This is due to the mixed order in which these locks are released
and acquired in such method as the slave threads start and stop methods.
*/
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);
void set_slave_thread_options(THD* thd);
void set_slave_thread_default_charset(THD *thd, Relay_log_info const *rli);
int apply_event_and_update_pos(Log_event* ev, THD* thd, Relay_log_info* rli);
int rotate_relay_log(Master_info* mi, bool need_log_space_lock);
bool queue_event(Master_info* mi,const char* buf, ulong event_len);
extern "C" void *handle_slave_io(void *arg);
extern "C" void *handle_slave_sql(void *arg);
bool net_request_file(NET* net, const char* fname);
extern bool volatile abort_loop;
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, *relay_log_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, *master_tls_version;
extern char *master_ssl_cipher, *master_ssl_key;
bool mts_recovery_groups(Relay_log_info *rli);
bool mts_checkpoint_routine(Relay_log_info *rli, ulonglong period,
bool force, bool need_data_lock);
bool sql_slave_killed(THD* thd, Relay_log_info* rli);
#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
Reference in New Issue View Git Blame Copy Permalink