原創：知數堂

上一篇文章，我們詳細介紹了 Xenon 實作 MySQL 高可用架構的部署程序，接下來本篇將介紹 Xenon 的常用操作，幫助大家在完成環境搭建之后，能把 Xenon 熟練的用起來，以更好的對 MySQL 高可用架構進行管理，

| 1 啟動集群

1.1 啟動 MySQL

# db1:
[mysql@db1 ~]$ nohup mysqld_safe --defaults-file=/etc/my.cnf &
[1] 5526
[mysql@db1 ~]$ nohup: ignoring input and appending output to ‘nohup.out’
 
# db2:
[mysql@db2 ~]$ nohup mysqld_safe --defaults-file=/etc/my.cnf &
[1] 3637
[mysql@db2 ~]$ nohup: ignoring input and appending output to 'nohup.out'
mysql –uroot –p    # 開啟增強半同步
set global  rpl_semi_sync_slave_enabled=1;
stop  slave io_thread;
start slave  io_thread;

db3 的啟動步驟同 db2，

1.2 啟動 Xenon

db1:
[mysql@db1 ~]$ cd /usr/local/xenon/bin/
[mysql@db1 bin]$ ./xenon -c /etc/xenon/xenon.json > /etc/xenon/log/xenon.log 2>&1 &

db2、db3 的啟動方式同 db1，

注意：當 MySQL 未啟動時，啟動 Xenon 會自動啟動 MySQL，

1.3 檢查半同步復制

啟動時，需要檢查半同步復制是否開啟，

(product)root@localhost [(none)]> show variables like '%semi%';
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 10000      |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
| rpl_semi_sync_slave_enabled               | OFF        |
| rpl_semi_sync_slave_trace_level           | 32         |
……

主要引數：主節點rpl_semi_sync_master_enabled 的狀態為 ON，從節點 rpl_semi_sync_slave_enabled 的狀態為 ON，表示半同步復制正常開啟，

| 2 幫助命令

通過 xenoncli 的幫助命令查看可選的命令，

[mysql@db1 bin]$ ./xenoncli  help
A simple command line client for xenon
 
Usage:
  xenoncli [command]

Available Commands:
  cluster     cluster related commands
  init        init the xenon config file
  mysql       mysql related commands
  perf        perf related commands
  raft        raft related commands
  version     Print the version number of xenon client
  xenon       xenon related commands
 
Use "xenoncli [command] --help" for more information about a command.

舉例說明，查看 cluster 的操作命令幫助，

[mysql@db1 bin]$  ./xenoncli cluster -h
cluster related commands
Usage:
  xenoncli cluster [command]
 
Available Commands:
  add         add peers to leader(if there is no leader, add to local)
  gtid        show cluster gtid status
  log         merge cluster xenon.log from logdir
  mysql       show cluster mysql status
  raft        show cluster raft status
  remove      remove peers from leader(if there is no leader, remove from local)
  status      show cluster status
  xenon       show cluster xenon status
 
Use "xenoncli cluster [command] --help" for more information about a command.

| 3 查看集群

3.1 查看狀態

xenoncli cluster status

xenoncli cluster mysql

xenoncli cluster xenon

file

3.2 檢查集群一致狀態

xenoncli cluster raft

file

3.3 檢查集群 GTID 狀態

xenoncli cluster gtid

file

| 4 關閉集群

xenoncli mysql stopmonitor
xenoncli mysql shutdown
pkill xenon

| 5 添加/洗掉節點

5.1 添加節點

xenoncli cluster add 192.168.0.2:8801,192.168.0.3:8801,192.168.0.5:8801

Xenon 允許添加已經添加過的節點，如果節點已經在集群里面，將直接被忽視，不做任何操作，

5.2 洗掉節點

xenoncli cluster  remove 192.168.0.2:8801,192.168.0.3:8801,192.168.0.5:8801

| 6 備份 MySQL 到本地

[root@db1 backup]# xenoncli mysql backup
Usage:
  xenoncli mysql backup --to=backupdir [flags]
[mysql@db1 bin]$ ./xenoncli mysql backup --to=/backup/data
 2020/02/10 04:28:43.924306       [WARNING]     rebuildme.found.best.slave[10.10.10.11:8801].leader[10.10.10.10:8801]
 2020/02/10 04:28:43.924576       [WARNING]     S1-->found.the.best.backup.host[10.10.10.11:8801]....
 2020/02/10 04:28:43.945828       [WARNING]     S2-->rm.and.mkdir.backupdir[/backup/data]
 2020/02/10 04:28:43.945845       [WARNING]     S3-->xtrabackup.begin....
 2020/02/10 04:28:43.946692       [WARNING]     rebuildme.backup.req[&{From: BackupDir:/backup/data SSHHost:10.10.10.10 SSHUser:mysql SSHPasswd:123456 SSHPort:22 IOPSLimits:100000 XtrabackupBinDir:/usr/bin}].from[10.10.10.11:8801]
 2020/02/10 04:29:06.360412       [WARNING]     S3-->xtrabackup.end....
 2020/02/10 04:29:06.360444       [WARNING]     S4-->apply-log.begin....
 2020/02/10 04:29:11.010835       [WARNING]     S4-->apply-log.end....
 2020/02/10 04:29:11.011275       [WARNING]     completed OK!
 2020/02/10 04:29:11.011300       [WARNING]     backup.all.done....

因 xenoncli 會嘗試先洗掉 backupdir 再 mkdir，故不建議使用 /backup 根目錄路徑，若使用這種路徑，rm 可以成功，mkdir 會失敗，

| 7 Rebuild 重建

選擇最佳狀態的從節點，進行 XtraBackup 流式重建，from 引數可指定重建源節點，

作用：重建當前節點 MySQL
場景：節點壞掉需要快速重建

// 在要做重建的節點執行： 
xenoncli mysql rebuildme

// 如果想以指定節點為準重建，執行： 
xenoncli mysql -h

// 基于指定節點復制重建當前 MySQL 節點
[mysql@db1 bin]$ ./xenoncli mysql rebuildme --from=10.10.10.11:8801
 2020/02/11 01:19:40.907645       [WARNING]     =====prepare.to.rebuildme=====
                        IMPORTANT: Please check that the backup run completes successfully.
                                   At the end of a successful backup run innobackupex
                                   prints "completed OK!".
 
 2020/02/11 01:19:40.908418       [WARNING]     S1-->check.raft.leader
 2020/02/11 01:19:40.911586       [WARNING]     S2-->prepare.rebuild.from[10.10.10.11:8801]....
 2020/02/11 01:19:40.913050       [WARNING]     S3-->check.bestone[10.10.10.11:8801].is.OK....
 2020/02/11 01:19:40.913066       [WARNING]     S4-->set.learner
 2020/02/11 01:19:40.915499       [WARNING]     S5-->stop.monitor
 2020/02/11 01:19:40.916758       [WARNING]     S6-->kill.mysql
 2020/02/11 01:19:40.947717       [WARNING]     S7-->check.bestone[10.10.10.11:8801].is.OK....
 2020/02/11 01:19:40.950867       [WARNING]     S8-->rm.datadir[/backup/data]
 2020/02/11 01:19:40.950879       [WARNING]     S9-->xtrabackup.begin....
 2020/02/11 01:19:40.951632       [WARNING]     rebuildme.backup.req[&{From: BackupDir:/backup/data SSHHost:10.10.10.10 SSHUser:mysql SSHPasswd:123456 SSHPort:22 IOPSLimits:100000 XtrabackupBinDir:/usr/bin}].from[10.10.10.11:8801]
 2020/02/11 01:19:51.200092       [WARNING]     S9-->xtrabackup.end....
 2020/02/11 01:19:51.200116       [WARNING]     S10-->apply-log.begin....
 2020/02/11 01:19:56.666199       [WARNING]     S10-->apply-log.end....
 2020/02/11 01:19:56.666209       [WARNING]     S11-->start.mysql.begin...
 2020/02/11 01:19:56.666757       [WARNING]     S11-->start.mysql.end...
 2020/02/11 01:19:56.666766       [WARNING]     S12-->wait.mysqld.running.begin....
 2020/02/11 01:19:59.680987       [WARNING]     wait.mysqld.running...
 2020/02/11 01:19:59.709382       [WARNING]     S12-->wait.mysqld.running.end....
 2020/02/11 01:19:59.709395       [WARNING]     S13-->wait.mysql.working.begin....
 2020/02/11 01:19:59.710943       [WARNING]     S13-->wait.mysql.working.end....
 2020/02/11 01:19:59.710955       [WARNING]     S14-->stop.and.reset.slave.begin....
 2020/02/11 01:19:59.731108       [WARNING]     S14-->stop.and.reset.slave.end....
 2020/02/11 01:19:59.731121       [WARNING]     S15-->reset.master.begin....
 2020/02/11 01:19:59.739414       [WARNING]     S15-->reset.master.end....
 2020/02/11 01:19:59.739455       [WARNING]     S15-->set.gtid_purged[1520b6dd-2fb1-11ea-ab64-080027d70146:1-14
].begin....
 2020/02/11 01:19:59.742273       [WARNING]     S15-->set.gtid_purged.end....
 2020/02/11 01:19:59.742284       [WARNING]     S16-->enable.raft.begin...
 2020/02/11 01:19:59.743512       [WARNING]     S16-->enable.raft.done...
 2020/02/11 01:19:59.743534       [WARNING]     S17-->wait[3000 ms].change.to.master...
 2020/02/11 01:19:59.743551       [WARNING]     S18-->start.slave.begin....
 2020/02/11 01:19:59.763468       [WARNING]     S18-->start.slave.end....
 2020/02/11 01:19:59.763478       [WARNING]     completed OK!

| 8 手動 Failover/switchover

手動觸發主從切換，

(product)root@localhost [(none)]> set global read_only=on;
Query OK, 0 rows affected (0.00 sec)
 
[mysql@db1 bin]$ ./xenoncli raft trytoleader
 2020/02/11 01:48:51.219975       [WARNING]     [10.10.10.10:8801].prepare.to.propose.this.raft.to.leader
 2020/02/11 01:48:51.255617       [WARNING]     [10.10.10.10:8801].propose.done
[mysql@db1 bin]$ ./xenoncli  cluster status
+------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+------------------+
|        ID        |             Raft              | Mysqld  | Monitor |          Backup          |        Mysql        | IO/SQL_RUNNING |     MyLeader     |
+------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+------------------+
| 10.10.10.10:8801 | [ViewID:4 EpochID:0]@LEADER   | RUNNING | ON      | state:[NONE]
            | [ALIVE] [READWRITE] | [true/true]    | 10.10.10.10:8801 |
|                  |                               |         |         | LastError:               |                     |                |                  |
+------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+------------------+
| 10.10.10.11:8801 | [ViewID:4 EpochID:0]@FOLLOWER | RUNNING | ON      | state:[NONE]
            | [ALIVE] [READONLY]  | [true/true]    | 10.10.10.10:8801 |
|                  |                               |         |         | LastError:               |                     |                |                  |
+------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+------------------+
| 10.10.10.18:8801 | [ViewID:4 EpochID:0]@FOLLOWER | RUNNING | ON      | state:[NONE]
            | [ALIVE] [READONLY]  | [true/true]    | 10.10.10.10:8801 |
|                  |                               |         |         | LastError:               |                     |                |                  |
+------------------+-------------------------------+---------+---------+--------------------------+---------------------+----------------+------------------+

| 9 MySQL Stack Info

查看 MySQL 如何呼叫堆疊資訊，Quick Stack 功能速度快，對流程幾乎沒有影響，

xenoncli perf -h
perf related commands
 
Usage:
  xenoncli perf [command]
 
Available Commands:
  quickstack  capture the stack of mysqld using quickstack

| 10 Raft + Operation

不發起選主 enable 是恢復，disable 指該 Xenon 節點只復制，

xenoncli raft -h
raft related commands
 
Usage:
  xenoncli raft [command]
 
Available Commands:
  add                add peers to local
  disable            enable the node out control of raft
  disablepurgebinlog disable leader to purge binlog
  enable             enable the node in control of raft
  enablepurgebinlog  enable leader to purge binlog(default)
  nodes              show raft nodes
  remove             remove peers from local
  status             status in JSON(state(LEADER/CANDIDATE/FOLLOWER/IDLE))
  trytoleader        propose this raft as leader

| 11 啟動增強半同步檢查

# 啟動半同步復制檢查
xenoncli raft enablechecksemisync

# 啟動或關閉半同步復制檢查
xenoncli raft disablechecksemisync

我們可以看到半同步的引數是：

(product)root@localhost [(none)]> show variables like '%rpl%';
+-------------------------------------------+---------------------+
| Variable_name                             | Value               |
+-------------------------------------------+---------------------+
| rpl_semi_sync_master_enabled              | ON                  |
| rpl_semi_sync_master_timeout              | 1000000000000000000 |
| rpl_semi_sync_master_trace_level          | 32                  |
| rpl_semi_sync_master_wait_for_slave_count | 1                   |
| rpl_semi_sync_master_wait_no_slave        | ON                  |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC          |
| rpl_semi_sync_slave_enabled               | ON                  |
| rpl_semi_sync_slave_trace_level           | 32                  |
| rpl_stop_slave_timeout                    | 31536000            |
+-------------------------------------------+---------------------+

若通過 set global 修改半同步的 timeout，將自動訂正為無限大；若基于運維臨時調整，需要先執行 xenoncli mysql disablechecksemisync 再修改；若運維完，需要恢復自動訂正的話，執行 enablechecksemisync ，

// 例如：修改 timeout 引數為 10,
(product)root@localhost [(none)]> set global rpl_semi_sync_master_timeout=10;
Query OK, 0 rows affected (0.00 sec)
 
(product)root@localhost [(none)]> show variables like '%rpl%';
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 10         |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
| rpl_semi_sync_slave_enabled               | ON         |
| rpl_semi_sync_slave_trace_level           | 32         |
| rpl_stop_slave_timeout                    | 31536000   |
+-------------------------------------------+------------+
9 rows in set (0.00 sec)
 
// 過一會兒又自動變為無窮大了
(product)root@localhost [(none)]> show variables like '%rpl%';
+-------------------------------------------+---------------------+
| Variable_name                             | Value               |
+-------------------------------------------+---------------------+
| rpl_semi_sync_master_enabled              | ON                  |
| rpl_semi_sync_master_timeout              | 1000000000000000000 |
| rpl_semi_sync_master_trace_level          | 32                  |
| rpl_semi_sync_master_wait_for_slave_count | 1                   |
| rpl_semi_sync_master_wait_no_slave        | ON                  |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC          |
| rpl_semi_sync_slave_enabled               | ON                  |
| rpl_semi_sync_slave_trace_level           | 32                  |
| rpl_stop_slave_timeout                    | 31536000            |
+-------------------------------------------+---------------------+
9 rows in set (0.00 sec)

| 指令分類

查詢集群資訊：

xenoncli cluster 指令

操作本機的：

xenoncli raft 指令
xenoncli perf quickstack
xenoncli mysql backup | cancelbackup | kill | rebuildme | shutdown | start | startmonitor |status | stopmonitor | sysvar

先嘗試連接到 Leader 執行，如果沒有 Leader，則在本機執行：

xenoncli mysql changepassword | createsuperuser | createuser | createuserwithgrants |
dropuser | getuser

下期預告

下期我們將介紹 Xenon 組態檔相關的使用，

推薦閱讀：

高可用 | Xenon 實作 MySQL 高可用架構部署篇
高可用 | Xenon：后 MHA 時代的選擇

轉載請註明出處，本文鏈接：https://www.uj5u.com/shujuku/297061.html

標籤：其他

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高可用 | Xenon 實作 MySQL 高可用架構 常用操作篇

| 1 啟動集群

1.1 啟動 MySQL

1.2 啟動 Xenon

1.3 檢查半同步復制

| 2 幫助命令

| 3 查看集群

3.1 查看狀態

3.2 檢查集群一致狀態

3.3 檢查集群 GTID 狀態

| 4 關閉集群

| 5 添加/洗掉節點

5.1 添加節點

5.2 洗掉節點

| 6 備份 MySQL 到本地

| 7 Rebuild 重建

| 8 手動 Failover/switchover

| 9 MySQL Stack Info

| 10 Raft + Operation

| 11 啟動增強半同步檢查

| 指令分類

下期預告

高可用 | Xenon 實作 MySQL 高可用架構常用操作篇