mirror of
https://github.com/MariaDB/server.git
synced 2025-01-23 15:24:16 +01:00
a48ff22004
NOTE: Backporting the patch to next-mr.
The fix proposed in BUG#35542 and BUG#31665 introduces a performance issue
when fsyncing the master.info, relay.info and relay-log.bin* after #th events.
Although such solution has been proposed to reduce the probability of corrupted
files due to a slave-crash, the performance penalty introduced by it has
made the approach impractical for highly intensive workloads.
In a nutshell, the option --syn-relay-log proposed in BUG#35542 and BUG#31665
simultaneously fsyncs master.info, relay-log.info and relay-log.bin* and
this is the main source of performance issues.
This patch introduces new options that give more control to the user on
what should be fsynced and how often:
1) (--sync-master-info, integer) which syncs the master.info after #th event;
2) (--sync-relay-log, integer) which syncs the relay-log.bin* after #th
events.
3) (--sync-relay-log-info, integer) which syncs the relay.info after #th
transactions.
To provide both performance and increased reliability, we recommend the following
setup:
1) --sync-master-info = 0 eventually the operating system will fsync it;
2) --sync-relay-log = 0 eventually the operating system will fsync it;
3) --sync-relay-log-info = 1 fsyncs it after every transaction;
Notice, that the previous setup does not reduce the probability of
corrupted master.info and relay-log.bin*. To overcome the issue, this patch also
introduces a recovery mechanism that right after restart throws away relay-log.bin*
retrieved from a master and updates the master.info based on the relay.info:
4) (--relay-log-recovery, boolean) which enables a recovery mechanism that
throws away relay-log.bin* after a crash.
However, it can only recover the incorrect binlog file and position in master.info,
if other informations (host, port password, etc) are corrupted or incorrect,
then this recovery mechanism will fail to work.
62 lines
1.4 KiB
Text
62 lines
1.4 KiB
Text
stop slave;
|
|
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
|
|
reset master;
|
|
reset slave;
|
|
drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
|
|
start slave;
|
|
show variables like 'relay_log%';
|
|
Variable_name Value
|
|
relay_log MYSQLD_DATADIR/relay-log
|
|
relay_log_index
|
|
relay_log_info_file relay-log.info
|
|
relay_log_purge ON
|
|
relay_log_recovery OFF
|
|
relay_log_space_limit 0
|
|
stop slave;
|
|
change master to master_host='127.0.0.1',master_user='root',
|
|
master_password='',master_port=MASTER_PORT;
|
|
start slave;
|
|
stop slave;
|
|
change master to master_host='127.0.0.1',master_user='root',
|
|
master_password='',master_port=SLAVE_PORT;
|
|
include/start_slave.inc
|
|
FLUSH LOGS;
|
|
SHOW SLAVE STATUS;
|
|
Slave_IO_State #
|
|
Master_Host 127.0.0.1
|
|
Master_User root
|
|
Master_Port SLAVE_PORT
|
|
Connect_Retry 60
|
|
Master_Log_File slave-bin.000001
|
|
Read_Master_Log_Pos POSITION
|
|
Relay_Log_File #
|
|
Relay_Log_Pos #
|
|
Relay_Master_Log_File slave-bin.000001
|
|
Slave_IO_Running Yes
|
|
Slave_SQL_Running Yes
|
|
Replicate_Do_DB
|
|
Replicate_Ignore_DB
|
|
Replicate_Do_Table
|
|
Replicate_Ignore_Table #
|
|
Replicate_Wild_Do_Table
|
|
Replicate_Wild_Ignore_Table
|
|
Last_Errno 0
|
|
Last_Error
|
|
Skip_Counter 0
|
|
Exec_Master_Log_Pos POSITION
|
|
Relay_Log_Space #
|
|
Until_Condition None
|
|
Until_Log_File
|
|
Until_Log_Pos 0
|
|
Master_SSL_Allowed No
|
|
Master_SSL_CA_File
|
|
Master_SSL_CA_Path
|
|
Master_SSL_Cert
|
|
Master_SSL_Cipher
|
|
Master_SSL_Key
|
|
Seconds_Behind_Master #
|
|
Master_SSL_Verify_Server_Cert #
|
|
Last_IO_Errno #
|
|
Last_IO_Error
|
|
Last_SQL_Errno 0
|
|
Last_SQL_Error
|