0.58 MHA 基於GTID的恢復不會從原Master拉取差異日誌且不再需要relay_log_purge=0!

MySQL MHA–故障切換模式(GTID模式和非GTID模式)
MHA with binlog server

這兩篇文章結論就是
MHA has changed failover procedure when turn on GTID.

• 1.If you want to use binlog server you must open GTID (I don’t know why Yoshi design like this)
• 2.MHA will not use relay-log to reocver (apply_diff_relay_logs will not be used ,just change master to lastest slave to recover with GTID)
• 3.if there’s no binlog server setting. MHA will ignore master binlog (even Manager node can ssh to Master server)
• 4.if you do not set binlog server on MHA, data may lost (MHA just keep all slaves consistent,so if lastest slave has lag data will be lost)
• 5.you can set multiple binlog server ,MHA will check them orderly,you can even set Master server as binlog server.

另外基於GTID的MHA failover不需要relay log, binlog就可以 relay_log_purge可以設置爲1

https://yq.aliyun.com/articles/58920/#

這個需要實際測試一下, 不過按照上面的第二條來看, 只要chang就行了, slave開了binlog和log_slave_updates就行, 這一般沒有人會不開的. 這樣看的話線上沒必要設置relay_log_purge=0了

如果是基於GTID的 failover ,不會從原master去拉差異binlog, 如果沒配置binlog server就可能丟數據

看代碼也確實是這樣

另外看manager啓動日誌也發現

n Mar  1 21:21:01 2020 - [info] GTID (with auto-pos) is supported. Skipping all SSH and Node package checking.

不檢查ssh了

代碼中也可以看到如果開了GTID就不查了

我實際測試也確實沒有走3.2這一步save binlog

Fri Feb 28 20:55:02 2020 - [info] * Phase 3: Master Recovery Phase..
Fri Feb 28 20:55:02 2020 - [info] 
Fri Feb 28 20:55:02 2020 - [info] * Phase 3.1: Getting Latest Slaves Phase..
Fri Feb 28 20:55:02 2020 - [info] 
Fri Feb 28 20:55:02 2020 - [info] The latest binary log file/position on all slaves is mysql-bin.000004:234
Fri Feb 28 20:55:02 2020 - [info] Latest slaves (Slaves that received relay log files to the latest):
Fri Feb 28 20:55:02 2020 - [info] 192.168.98.10(192.168.98.10:3306) Version=5.7.29-32-log (oldest major version between slaves) log-bin:enabled
Fri Feb 28 20:55:02 2020 - [info] GTID ON
Fri Feb 28 20:55:02 2020 - [info] Replicating from 192.168.98.11(192.168.98.11:3306)
Fri Feb 28 20:55:02 2020 - [info] Primary candidate for the new Master (candidate_master is set)
Fri Feb 28 20:55:02 2020 - [info] 192.168.98.12(192.168.98.12:3306) Version=5.7.29-32-log (oldest major version between slaves) log-bin:enabled
Fri Feb 28 20:55:02 2020 - [info] GTID ON
Fri Feb 28 20:55:02 2020 - [info] Replicating from 192.168.98.11(192.168.98.11:3306)
Fri Feb 28 20:55:02 2020 - [info] The oldest binary log file/position on all slaves is mysql-bin.000004:234
Fri Feb 28 20:55:02 2020 - [info] Oldest slaves:
Fri Feb 28 20:55:02 2020 - [info] 192.168.98.10(192.168.98.10:3306) Version=5.7.29-32-log (oldest major version between slaves) log-bin:enabled
Fri Feb 28 20:55:02 2020 - [info] GTID ON
Fri Feb 28 20:55:02 2020 - [info] Replicating from 192.168.98.11(192.168.98.11:3306)
Fri Feb 28 20:55:02 2020 - [info] Primary candidate for the new Master (candidate_master is set)
Fri Feb 28 20:55:02 2020 - [info] 192.168.98.12(192.168.98.12:3306) Version=5.7.29-32-log (oldest major version between slaves) log-bin:enabled
Fri Feb 28 20:55:02 2020 - [info] GTID ON
Fri Feb 28 20:55:02 2020 - [info] Replicating from 192.168.98.11(192.168.98.11:3306)
Fri Feb 28 20:55:02 2020 - [info] 
Fri Feb 28 20:55:02 2020 - [info] * Phase 3.3: Determining New Master Phase..
Fri Feb 28 20:55:02 2020 - [info] 
Fri Feb 28 20:55:02 2020 - [info] Searching new master from slaves..
Fri Feb 28 20:55:02 2020 - [info] Candidate masters from the configuration file:

這有個文章也說了這個問題mha 0.58 gtid模式下 丟數據問題修復

那麼要麼按照上面的文章改代碼

要麼就按照MHA with binlog server文章中說的配置binlog server.

MHA check binlog server 1 and find error with binlog then try to recover from binlog server 2.

With this feature we can add master server as first binlog server to guarantee no binlog loss.If master server crash and can not been reached,binlog server 2 will also provide service.

將原主庫配置成binlog server 1, 然後再拍一個binlog server. 因爲binlog server也不是半同步的, 也可能缺binlog

[server1]
hostname=192.168.98.10
candidate_master=1

[server2]
hostname=192.168.98.11
candidate_master=1

[server3]
hostname=192.168.98.12
# no_master=1

[binlog1]
no_master=1
hostname=192.168.98.10
master_binlog_dir=/data/mysql_3306/data/

按此配置啓動manager後可以看到日誌

Sun Mar  1 21:38:16 2020 - [info] Binlog server 192.168.98.10 is reachable.
Sun Mar  1 21:38:16 2020 - [info] Checking recovery script configurations on 192.168.98.10(192.168.98.10:3306)..
Sun Mar  1 21:38:16 2020 - [info]   Executing command: save_binary_logs --command=test --start_pos=4 --binlog_dir=/data/mysql_3306/data/ --output_file=/masterha//save_binary_logs_test --manager_version=0.58 --start_file=mysql-bin.000014 
Sun Mar  1 21:38:16 2020 - [info]   Connecting to [email protected](192.168.98.10:22).. 
  Creating /masterha if not exists..    ok.
  Checking output directory is accessible or not..
   ok.
  Binlog found at /data/mysql_3306/data/, up to mysql-bin.000014
Sun Mar  1 21:38:17 2020 - [info] Binlog setting check done.

嘗試failover, 可以看到日誌中多了

Sun Mar  1 21:43:37 2020 - [info] -- Saving binlog from host 192.168.98.10 started, pid: 98503
Sun Mar  1 21:43:39 2020 - [info] 
Sun Mar  1 21:43:39 2020 - [info] Log messages from 192.168.98.10 ...
Sun Mar  1 21:43:39 2020 - [info] 
Sun Mar  1 21:43:37 2020 - [info] Fetching binary logs from binlog server 192.168.98.10..
Sun Mar  1 21:43:37 2020 - [info] Executing binlog save command: save_binary_logs --command=save --start_file=mysql-bin.000014  --start_pos=234 --output_file=/masterha//saved_binlog_binlog1_20200301214334.binlog --handle_raw_binlog=0 --skip_filter=1 --disable_log_bin=0 --manager_version=0.58 --oldest_version=5.7.29-32-log  --binlog_dir=/data/mysql_3306/data/ 
  Creating /masterha if not exists..    ok.
 Concat binary/relay logs from mysql-bin.000014 pos 234 to mysql-bin.000014 EOF into /masterha//saved_binlog_binlog1_20200301214334.binlog ..
 Concat succeeded.
Sun Mar  1 21:43:39 2020 - [info] scp from [email protected]:/masterha//saved_binlog_binlog1_20200301214334.binlog to local:/masterha/cls_all//saved_binlog_192.168.98.10_binlog1_20200301214334.binlog succeeded.
Sun Mar  1 21:43:39 2020 - [info] End of log messages from 192.168.98.10.
Sun Mar  1 21:43:39 2020 - [info] Saved mysqlbinlog size from 192.168.98.10 is 820 bytes.

沒配置binlog server的日誌

Fri Feb 28 20:55:02 2020 - [info] * Phase 3.3: New Master Recovery Phase..
Fri Feb 28 20:55:02 2020 - [info] 
Fri Feb 28 20:55:02 2020 - [info]  Waiting all logs to be applied.. 
Fri Feb 28 20:55:02 2020 - [info]   done.
Fri Feb 28 20:55:02 2020 - [info] Getting new master's binlog name and position..
Fri Feb 28 20:55:02 2020 - [info]  mysql-bin.000010:234
Fri Feb 28 20:55:02 2020 - [info]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='192.168.98.10', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='repler', MASTER_PASSWORD='xxx';
Fri Feb 28 20:55:02 2020 - [info] Master Recovery succeeded. File:Pos:Exec_Gtid_Set: mysql-bin.000010, 234, 3a60f8c7-592c-11ea-8cb1-000c2973aaf0:1-6,
68703597-592c-11ea-88b3-000c2998280b:1-4
Fri Feb 28 20:55:02 2020 - [info] Executing master IP activate script:

配置了binlog server的日誌

Sun Mar  1 21:43:37 2020 - [info] * Phase 3.3: New Master Recovery Phase..
Sun Mar  1 21:43:37 2020 - [info] 
Sun Mar  1 21:43:37 2020 - [info]  Waiting all logs to be applied.. 
Sun Mar  1 21:43:37 2020 - [info]   done.
Sun Mar  1 21:43:37 2020 - [info] -- Saving binlog from host 192.168.98.10 started, pid: 98503
Sun Mar  1 21:43:39 2020 - [info] 
Sun Mar  1 21:43:39 2020 - [info] Log messages from 192.168.98.10 ...
Sun Mar  1 21:43:39 2020 - [info] 
Sun Mar  1 21:43:37 2020 - [info] Fetching binary logs from binlog server 192.168.98.10..
Sun Mar  1 21:43:37 2020 - [info] Executing binlog save command: save_binary_logs --command=save --start_file=mysql-bin.000014  --start_pos=234 --output_file=/masterha//saved_binlog_binlog1_20200301214334.binlog --handle_raw_binlog=0 --skip_filter=1 --disable_log_bin=0 --manager_version=0.58 --oldest_version=5.7.29-32-log  --binlog_dir=/data/mysql_3306/data/ 
  Creating /masterha if not exists..    ok.
 Concat binary/relay logs from mysql-bin.000014 pos 234 to mysql-bin.000014 EOF into /masterha//saved_binlog_binlog1_20200301214334.binlog ..
 Concat succeeded.
Sun Mar  1 21:43:39 2020 - [info] scp from [email protected]:/masterha//saved_binlog_binlog1_20200301214334.binlog to local:/masterha/cls_all//saved_binlog_192.168.98.10_binlog1_20200301214334.binlog succeeded.
Sun Mar  1 21:43:39 2020 - [info] End of log messages from 192.168.98.10.
Sun Mar  1 21:43:39 2020 - [info] Saved mysqlbinlog size from 192.168.98.10 is 820 bytes.
Sun Mar  1 21:43:39 2020 - [info] Checking if super_read_only is defined and turned on..
Sun Mar  1 21:43:39 2020 - [info]  not present or turned off, ignoring.
Sun Mar  1 21:43:39 2020 - [info] Applying differential binlog /masterha/cls_all//saved_binlog_192.168.98.10_binlog1_20200301214334.binlog ..
Sun Mar  1 21:43:39 2020 - [info] Differential log apply from binlog server succeeded.
Sun Mar  1 21:43:39 2020 - [info] Getting new master's binlog name and position..
Sun Mar  1 21:43:39 2020 - [info]  mysql-bin.000012:234
Sun Mar  1 21:43:39 2020 - [info]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='192.168.98.11', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='repler', MASTER_PASSWORD='xxx';
Sun Mar  1 21:43:39 2020 - [info] Master Recovery succeeded. File:Pos:Exec_Gtid_Set: mysql-bin.000012, 234, 3a60f8c7-592c-11ea-8cb1-000c2973aaf0:1-7,
68703597-592c-11ea-88b3-000c2998280b:1-74
Sun Mar  1 21:43:39 2020 - [info] Executing master IP activate script:

當然如果你說你是MHA加半同步, 那麼這些你可能都不用關心了