Redis主從集羣的Sentinel配置

時間  2019-11-24
標籤 redis 主從 集羣 sentinel 配置 欄目 Redis 简体版
原文   原文鏈接

http://www.cnblogs.com/LiZhiW/p/4851631.htmlhtml

 

1.集羣環境

1.Linux服務器列表redis

使用4臺CentOS Linux服務器搭建環境，其IP地址以下：數據庫

  1. 192.168.110.100
  2. 192.168.110.101
  3. 192.168.110.102
  4. 192.168.110.103

2.Redis服務部署環境服務器

192.168.110.100app

啓動多個Redis sentinel服務，構成Redis sentinel集羣async

192.168.110.101測試

啓動Redis服務，設置成主節點this

192.168.110.102spa

啓動Redis服務，設置成192.168.110.101的從節點.net

192.168.110.103

啓動Redis服務，設置成192.168.110.101的從節點

回到頂部

2.配置並啓動Redis主從集羣

1.修改redis.conf配置文件

主節點的redis配置文件使用默認的配置文件就能夠了，從節點的redis配置文件修改以下：

  1. # Master-Slave replication. Use slaveof to make a Redis instance a copy of
  2. # another Redis server. A few things to understand ASAP about Redis replication.
  3. #
  4. # 1) Redis replication is asynchronous, but you can configure a master to
  5. # stop accepting writes if it appears to be not connected with at least
  6. # a given number of slaves.
  7. # 2) Redis slaves are able to perform a partial resynchronization with the
  8. # master if the replication link is lost for a relatively small amount of
  9. # time. You may want to configure the replication backlog size (see the next
  10. # sections of this file) with a sensible value depending on your needs.
  11. # 3) Replication is automatic and does not need user intervention. After a
  12. # network partition slaves automatically try to reconnect to masters
  13. # and resynchronize with them.
  14. #
  15. # 主從同步。經過 slaveof 配置來實現Redis實例的備份。
  16. # 注意，這裏是本地從遠端複製數據。也就是說，本地能夠有不一樣的數據庫文件、綁定不一樣的IP、監聽不一樣的端口。
  17. #
  18. # slaveof <masterip> <masterport>
  19. slaveof 192.168.110.1016379

注意:兩臺從節點都要改。

2.啓動Redis主從集羣

先啓動192.168.110.101主節點，使用默認配置，腳本：

  1. [wch@localhost bin]$ ./redis-server

再啓動192.168.110.102和192.168.110.103從節點，使用剛纔的配置，腳本：

  1. ./redis-server redis.conf

3.查看集羣

192.168.110.101主節點Replication信息

  1. [wch@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication
  2. # Replication
  3. role:master
  4. connected_slaves:2
  5. slave0:ip=192.168.110.102,port=6379,state=online,offset=659,lag=1
  6. slave1:ip=192.168.110.103,port=6379,state=online,offset=659,lag=0
  7. master_repl_offset:659
  8. repl_backlog_active:1
  9. repl_backlog_size:1048576
  10. repl_backlog_first_byte_offset:2
  11. repl_backlog_histlen:658

192.168.110.102從節點Replication信息

  1. [wch@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication
  2. # Replication
  3. role:slave
  4. master_host:192.168.110.101
  5. master_port:6379
  6. master_link_status:up
  7. master_last_io_seconds_ago:3
  8. master_sync_in_progress:0
  9. slave_repl_offset:701
  10. slave_priority:100
  11. slave_read_only:1
  12. connected_slaves:0
  13. master_repl_offset:0
  14. repl_backlog_active:0
  15. repl_backlog_size:1048576
  16. repl_backlog_first_byte_offset:0
  17. repl_backlog_histlen:0

192.168.110.103從節點Replication信息

  1. [wch@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication
  2. # Replication
  3. role:slave
  4. master_host:192.168.110.101
  5. master_port:6379
  6. master_link_status:up
  7. master_last_io_seconds_ago:9
  8. master_sync_in_progress:0
  9. slave_repl_offset:715
  10. slave_priority:100
  11. slave_read_only:1
  12. connected_slaves:0
  13. master_repl_offset:0
  14. repl_backlog_active:0
  15. repl_backlog_size:1048576
  16. repl_backlog_first_byte_offset:0
  17. repl_backlog_histlen:0

此時，存儲到192.168.110.101主節點的數據，在從節點中均可以查詢到。從節點會備份主節點的數據。

回到頂部

3.配置sentinel集羣並啓動

1.建立sentinel.conf配置文件

#--後臺運行
#daemonize yes

  1. port 26379
  2. # sentinel announce-ip <ip>
  3. # sentinel announce-port <port>
  4. dir /tmp
  5.  
  6. ################################# master001 #################################
  7. sentinel monitor master001 192.168.110.10163792
  8. # sentinel auth-pass <master-name> <password>
  9. sentinel down-after-milliseconds master001 30000
  10. sentinel parallel-syncs master001 1
  11. sentinel failover-timeout master001 180000
  12. # sentinel notification-script <master-name> <script-path>
  13. # sentinel client-reconfig-script <master-name> <script-path>
  14.  
  15. # 能夠配置多個master節點
  16. ################################# master002 #################################

 

 

 

另外一個配置標例


# Example sentinel.conf
#--後臺運行
#daemonize yes
# port <sentinel-port>
# The port that this sentinel instance will run on
port 26305
dir "/tmp"
sentinel monitor master05 192.168.25.110 16306 1
sentinel down-after-milliseconds master05 5000
sentinel failover-timeout master05 5000
sentinel parallel-syncs master05 2
# Generated by CONFIG REWRITE
#sentinel config-epoch master05 0
#sentinel leader-epoch master05 0
#sentinel known-slave master05 192.168.25.110 16307
#sentinel known-slave master05 192.168.25.110 16306
#sentinel known-sentinel master05 192.168.25.110 26308 6d6b069753b48875861aa8f11f1971c131e743ba
#sentinel current-epoch 0
sentinel config-epoch master05 12
sentinel leader-epoch master05 12
sentinel known-slave master05 192.168.25.110 16307
sentinel known-slave master05 192.168.25.110 16305
sentinel known-sentinel master05 192.168.25.110 26308 e032e2baa1bb1d8699f3323f2affe9a734e1ecea
sentinel current-epoch 12
 

配置文件說明：

1. port :當前Sentinel服務運行的端口

 

2. dir : Sentinel服務運行時使用的臨時文件夾

 

3.sentinel monitor master001 192.168.110.10163792:Sentinel去監視一個名爲master001的主redis實例，這個主實例的IP地址爲本機地址192.168.110.101，端口號爲6379，而將這個主實例判斷爲失效至少須要2個 Sentinel進程的贊成，只要贊成Sentinel的數量不達標，自動failover就不會執行

 

4.sentinel down-after-milliseconds master001 30000:指定了Sentinel認爲Redis實例已經失效所需的毫秒數。當實例超過該時間沒有返回PING，或者直接返回錯誤，那麼Sentinel將這個實例標記爲主觀下線。只有一個 Sentinel進程將實例標記爲主觀下線並不必定會引發實例的自動故障遷移：只有在足夠數量的Sentinel都將一個實例標記爲主觀下線以後，實例纔會被標記爲客觀下線，這時自動故障遷移纔會執行

 

5.sentinel parallel-syncs master001 1：指定了在執行故障轉移時，最多能夠有多少個從Redis實例在同步新的主實例，在從Redis實例較多的狀況下這個數字越小，同步的時間越長，完成故障轉移所需的時間就越長

 

6.sentinel failover-timeout master001 180000：若是在該時間（ms）內未能完成failover操做，則認爲該failover失敗

 

7.sentinel notification-script <master-name> <script-path>：指定sentinel檢測到該監控的redis實例指向的實例異常時，調用的報警腳本。該配置項可選，可是很經常使用

2.啓動sentinel集羣

建立3個sentinel.conf配置文件：sentinel001.conf、sentinel002.conf、sentinel003.conf並修改端口號分別爲：2637九、3637九、46379，並啓動服務：

  1. ./redis-sentinel sentinel001.conf
  2. ./redis-sentinel sentinel002.conf
  3. ./redis-sentinel sentinel003.conf

啓動三個sentinel服務後會在其控制檯看到以下信息：

./redis-sentinel sentinel001.conf，端口：26379

  1. [7743]01Oct06:20:38.162# Sentinel runid is ba6c42e1accc31290e11d5876275e1562564295d
  2. [7743]01Oct06:20:38.162# +monitor master master001 192.168.110.101 6379 quorum 2
  3. [7743]01Oct06:20:39.110*+slave slave 192.168.110.102:6379192.168.110.1026379@ master001 192.168.110.1016379
  4. [7743]01Oct06:20:39.111*+slave slave 192.168.110.103:6379192.168.110.1036379@ master001 192.168.110.1016379
  5. [7743]01Oct06:25:07.595*+sentinel sentinel 192.168.110.100:36379192.168.110.10036379@ master001 192.168.110.1016379
  6. [7743]01Oct06:26:11.170*+sentinel sentinel 192.168.110.100:46379192.168.110.10046379@ master001 192.168.110.1016379

./redis-sentinel sentinel002.conf，端口：36379

  1. [7795]01Oct06:25:05.538# Sentinel runid is 52c14768b15837fb601b26328acf150c6bd30682
  2. [7795]01Oct06:25:05.538# +monitor master master001 192.168.110.101 6379 quorum 2
  3. [7795]01Oct06:25:06.505*+slave slave 192.168.110.102:6379192.168.110.1026379@ master001 192.168.110.1016379
  4. [7795]01Oct06:25:06.515*+slave slave 192.168.110.103:6379192.168.110.1036379@ master001 192.168.110.1016379
  5. [7795]01Oct06:25:07.557*+sentinel sentinel 192.168.110.100:26379192.168.110.10026379@ master001 192.168.110.1016379
  6. [7795]01Oct06:26:11.168*+sentinel sentinel 192.168.110.100:46379192.168.110.10046379@ master001 192.168.110.1016379

./redis-sentinel sentinel003.conf，端口：46379

  1. [7828]01Oct06:26:09.076# Sentinel runid is c8509594be4a36660b2122b3b81f4f74060c9b04
  2. [7828]01Oct06:26:09.076# +monitor master master001 192.168.110.101 6379 quorum 2
  3. [7828]01Oct06:26:10.063*+slave slave 192.168.110.102:6379192.168.110.1026379@ master001 192.168.110.1016379
  4. [7828]01Oct06:26:10.071*+slave slave 192.168.110.103:6379192.168.110.1036379@ master001 192.168.110.1016379
  5. [7828]01Oct06:26:11.516*+sentinel sentinel 192.168.110.100:26379192.168.110.10026379@ master001 192.168.110.1016379
  6. [7828]01Oct06:26:11.674*+sentinel sentinel 192.168.110.100:36379192.168.110.10036379@ master001 192.168.110.1016379

每一個sentinel服務能知道其餘全部的服務！

回到頂部

4.測試sentinel集羣

1.中止192.168.110.101主節點

中止192.168.110.101Redis主節點後，在查看Replication信息以下：

  1. [wch@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication
  2. Could not connect to Redis at 192.168.110.101:6379:Connection refused
  3.  
  4. [wch@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication
  5. # Replication
  6. role:slave
  7. master_host:192.168.110.103
  8. master_port:6379
  9. master_link_status:up
  10. master_last_io_seconds_ago:1
  11. master_sync_in_progress:0
  12. slave_repl_offset:29128
  13. slave_priority:100
  14. slave_read_only:1
  15. connected_slaves:0
  16. master_repl_offset:0
  17. repl_backlog_active:0
  18. repl_backlog_size:1048576
  19. repl_backlog_first_byte_offset:0
  20. repl_backlog_histlen:0
  21.  
  22. [wch@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication
  23. # Replication
  24. role:master
  25. connected_slaves:1
  26. slave0:ip=192.168.110.102,port=6379,state=online,offset=30456,lag=1
  27. master_repl_offset:30456
  28. repl_backlog_active:1
  29. repl_backlog_size:1048576
  30. repl_backlog_first_byte_offset:2
  31. repl_backlog_histlen:30455
  32. [wch@localhost bin]$

發現192.168.110.101Redis主節點已經不能鏈接，192.168.110.103成了主節點！

2.再啓動192.168.110.101主節點

再啓動192.168.110.101Redis主節點後，在查看Replication信息以下：

  1. ### 啓動腳本，仍然使用默認配置
  2. [wch@localhost bin]$ ./redis-server
  3.  
  4. [wch@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication
  5. # Replication
  6. role:slave
  7. master_host:192.168.110.103
  8. master_port:6379
  9. master_link_status:up
  10. master_last_io_seconds_ago:1
  11. master_sync_in_progress:0
  12. slave_repl_offset:57657
  13. slave_priority:100
  14. slave_read_only:1
  15. connected_slaves:0
  16. master_repl_offset:0
  17. repl_backlog_active:0
  18. repl_backlog_size:1048576
  19. repl_backlog_first_byte_offset:0
  20. repl_backlog_histlen:0
  21.  
  22. [wch@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication
  23. # Replication
  24. role:slave
  25. master_host:192.168.110.103
  26. master_port:6379
  27. master_link_status:up
  28. master_last_io_seconds_ago:0
  29. master_sync_in_progress:0
  30. slave_repl_offset:60751
  31. slave_priority:100
  32. slave_read_only:1
  33. connected_slaves:0
  34. master_repl_offset:0
  35. repl_backlog_active:0
  36. repl_backlog_size:1048576
  37. repl_backlog_first_byte_offset:0
  38. repl_backlog_histlen:0
  39.  
  40. [wch@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication
  41. # Replication
  42. role:master
  43. connected_slaves:2
  44. slave0:ip=192.168.110.102,port=6379,state=online,offset=63247,lag=1
  45. slave1:ip=192.168.110.101,port=6379,state=online,offset=63247,lag=1
  46. master_repl_offset:63393
  47. repl_backlog_active:1
  48. repl_backlog_size:1048576
  49. repl_backlog_first_byte_offset:2
  50. repl_backlog_histlen:63392
  51. [wch@localhost bin]$

發現192.168.110.101節點啓動後還再集羣中，只不過成了從節點，192.168.110.103仍然是主節點，可是如今又有兩個從節點了！

3.只留下一個sentinel服務，再中止192.168.110.103主節點，查看Redis集羣是否出現新的主節點

中止sentinel服務，只留下一個sentinel服務，再中止Redis主節點，查看Replication信息以下：

  1. [wch@localhost bin]$ ./redis-cli -h 192.168.110.101 info Replication
  2. # Replication
  3. role:slave
  4. master_host:192.168.110.103
  5. master_port:6379
  6. master_link_status:down
  7. master_last_io_seconds_ago:-1
  8. master_sync_in_progress:0
  9. slave_repl_offset:184231
  10. master_link_down_since_seconds:43
  11. slave_priority:100
  12. slave_read_only:1
  13. connected_slaves:0
  14. master_repl_offset:0
  15. repl_backlog_active:0
  16. repl_backlog_size:1048576
  17. repl_backlog_first_byte_offset:0
  18. repl_backlog_histlen:0
  19.  
  20. [wch@localhost bin]$ ./redis-cli -h 192.168.110.102 info Replication
  21. # Replication
  22. role:slave
  23. master_host:192.168.110.103
  24. master_port:6379
  25. master_link_status:down
  26. master_last_io_seconds_ago:-1
  27. master_sync_in_progress:0
  28. slave_repl_offset:184231
  29. master_link_down_since_seconds:52
  30. slave_priority:100
  31. slave_read_only:1
  32. connected_slaves:0
  33. master_repl_offset:0
  34. repl_backlog_active:0
  35. repl_backlog_size:1048576
  36. repl_backlog_first_byte_offset:0
  37. repl_backlog_histlen:0
  38.  
  39. [wch@localhost bin]$ ./redis-cli -h 192.168.110.103 info Replication
  40. Could not connect to Redis at 192.168.110.103:6379:Connection refused

發現192.168.110.103主節點已經不能鏈接了，也不存在Redis主節點，集羣中無主節點了！！！分析緣由是：sentinel.conf配置的sentinel monitor master001 192.168.110.10163792最後一個參數是2致使，如果但節點此配置的最後一個參數要使用是1。(此緣由我已證明)

注意：在生產環境下建議sentinel節點的數量能在3個以上，而且最好不要在同一臺機器上(使用同一網卡)。

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