redis系列（五）：搭建redis-cluster叢集
阿新 • • 發佈：2019-01-03
1、為什麼要用redis-cluster
a、併發要求
redis官方聲稱可以達到10萬每秒，但是如果業務需要每秒100萬條呢？
b、資料量太大
一臺伺服器的記憶體正常是16-256G，如果業務需要500G記憶體怎麼辦？
2、搭建redis-cluster
針對上述問題，redis-cluster叢集就提供了很好的解決方案。
（1）、先準備環境，開啟多個redis例項
[[email protected] redis_conf]# ls redis-7000.conf redis-7002.conf redis-7004.conf redis-7001.conf redis-7003.conf redis-7005.conf [[email protected] redis_conf]#
暫時準備了6個配置檔案，
daemonize yes port 7000 logfile ./data/7000/redis.log #日誌存放位置 dir ./data/7000 # 資料存放位置 dbfilename dbmp.rdb # 資料檔名稱 cluster-enabled yes # 開啟叢集模式 cluster-config-file nodes-7000.conf # 叢集內部的配置檔案 cluster-require-full-coverage no # redis cluster需要16384個slot都正常的時候才能對外提供服務，換句話說，只要任何一個slot異常那麼整個cluster不對外提供服務。 因此生產環境一般為no
上面的配置為redis-7000.conf的配置檔案內容，其他配置檔案內容相同，只是將7000全部改成對應的埠。
可以使用如下命令快速生成：
sed "s/7000/7001/g" redis-7000.conf > redis-7001.conf
通過sed命令將redis-7000.conf中的7000修改成7001，然後寫入redis-7001.conf檔案中
每個節點僅僅是埠的不同。
注意：還要確保配置中的日誌以及資料存放資料夾存在。
比如我的：
[[email protected] redis_conf]# mkdir -p data/{7000,7001,7002,7003,7004,7005} [[email protected]redis_conf]# tree . ├── data │ ├── 7000 │ ├── 7001 │ ├── 7002 │ ├── 7003 │ ├── 7004 │ └── 7005 ├── redis-7000.conf ├── redis-7001.conf ├── redis-7002.conf ├── redis-7003.conf ├── redis-7004.conf └── redis-7005.conf 7 directories, 6 files
(2)、執行redis例項
[[email protected] redis_conf]# redis-server redis-7000.conf [[email protected] redis_conf]# redis-server redis-7001.conf [[email protected] redis_conf]# redis-server redis-7002.conf [[email protected] redis_conf]# redis-server redis-7003.conf [[email protected] redis_conf]# redis-server redis-7004.conf [[email protected] redis_conf]# redis-server redis-7005.conf
檢視是否已經啟動
[[email protected] redis_conf]# ps -ef | grep redis root 3733 1 0 08:13 ? 00:00:00 redis-server *:7000 [cluster] root 3763 1 0 08:13 ? 00:00:00 redis-server *:7001 [cluster] root 3768 1 0 08:13 ? 00:00:00 redis-server *:7002 [cluster] root 3773 1 0 08:13 ? 00:00:00 redis-server *:7003 [cluster] root 3779 1 0 08:13 ? 00:00:00 redis-server *:7004 [cluster] root 3784 1 0 08:13 ? 00:00:00 redis-server *:7005 [cluster] root 3816 3514 0 08:14 pts/0 00:00:00 grep --color=auto redis [[email protected] redis_conf]#
此時叢集還用不了，可以登入redis檢視
[[email protected] redis_conf]# redis-cli -p 7000 127.0.0.1:7000> set name felixi (error) CLUSTERDOWN Hash slot not served 127.0.0.1:7000>
(3)、建立redis-cluster
a、準備ruby環境
下載，編譯，安裝ruby （ruby官網地址）
1、下載（個人用的當前的最新版本2.6.0） wget https://cache.ruby-lang.org/pub/ruby/2.6/ruby-2.6.0.tar.gz 2、解壓，安裝 tar -zxvf ruby-2.6.0.tar.gz cd ruby-2.6.0 ./configure --prefix=/opt/ruby/ make && make install 3、新增環境變數 export PATH=/opt/ruby/bin/:$PATH # 將這句新增到./bashrc和/etc/profile檔案末尾。 source ./bashrc /etc/profile # 載入一下
b、檢視是否已經安裝
[[email protected] ~]# gem -v 3.0.1 [[email protected] ~]#
c、下載安裝ruby操作redis的模組包
[[email protected] ~]# gem install redis Successfully installed redis-4.1.0 Parsing documentation for redis-4.1.0 Done installing documentation for redis after 1 seconds 1 gem installed [[email protected] ~]#
7、啟動叢集
我的redis版本是5.0.2，使用如下方式啟動
redis-cli --cluster create 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 --cluster-replicas 1
其他舊版本可能需要如下命令：注意(redis-trib.rb可能找不到，可以通過find / -name redis-trib.rb來查詢)
/opt/redis-4.0.10/src/redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005
8、出現如下說明啟動成功
[[email protected] ~]# redis-cli --cluster create 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005 --cluster-replicas 1 >>> Performing hash slots allocation on 6 nodes... Master[0] -> Slots 0 - 5460 Master[1] -> Slots 5461 - 10922 Master[2] -> Slots 10923 - 16383 Adding replica 127.0.0.1:7003 to 127.0.0.1:7000 Adding replica 127.0.0.1:7004 to 127.0.0.1:7001 Adding replica 127.0.0.1:7005 to 127.0.0.1:7002 >>> Trying to optimize slaves allocation for anti-affinity [WARNING] Some slaves are in the same host as their master M: 511bc46a1da42e3964ce41f48234076bd5743baf 127.0.0.1:7000 slots:[0-5460] (5461 slots) master M: bb029209525fb9aa2eeaa8c27182065ca1b29457 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master M: 72b6ad9d36ba9cc7770bfaf6899c8e3262c677b0 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master S: 25c00188cc8b58f5442ac674647389ab4f9206e9 127.0.0.1:7003 replicates 511bc46a1da42e3964ce41f48234076bd5743baf S: bd093c559ebbc54fead2da9200d6f0c10a90bc87 127.0.0.1:7004 replicates bb029209525fb9aa2eeaa8c27182065ca1b29457 S: 3c0031255f960fbc15bbf9a78dacd7427ac24115 127.0.0.1:7005 replicates 72b6ad9d36ba9cc7770bfaf6899c8e3262c677b0 Can I set the above configuration? (type 'yes' to accept): yes >>> Nodes configuration updated >>> Assign a different config epoch to each node >>> Sending CLUSTER MEET messages to join the cluster Waiting for the cluster to join ... >>> Performing Cluster Check (using node 127.0.0.1:7000) M: 511bc46a1da42e3964ce41f48234076bd5743baf 127.0.0.1:7000 slots:[0-5460] (5461 slots) master 1 additional replica(s) M: 72b6ad9d36ba9cc7770bfaf6899c8e3262c677b0 127.0.0.1:7002 slots:[10923-16383] (5461 slots) master 1 additional replica(s) M: bb029209525fb9aa2eeaa8c27182065ca1b29457 127.0.0.1:7001 slots:[5461-10922] (5462 slots) master 1 additional replica(s) S: bd093c559ebbc54fead2da9200d6f0c10a90bc87 127.0.0.1:7004 slots: (0 slots) slave replicates bb029209525fb9aa2eeaa8c27182065ca1b29457 S: 25c00188cc8b58f5442ac674647389ab4f9206e9 127.0.0.1:7003 slots: (0 slots) slave replicates 511bc46a1da42e3964ce41f48234076bd5743baf S: 3c0031255f960fbc15bbf9a78dacd7427ac24115 127.0.0.1:7005 slots: (0 slots) slave replicates 72b6ad9d36ba9cc7770bfaf6899c8e3262c677b0 [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. [[email protected] ~]#
9、檢視主從狀態
redis-cli -p 7000 info replication
結果如下：
[[email protected] ~]# redis-cli -p 7002 info replication # Replication role:master connected_slaves:1 slave0:ip=127.0.0.1,port=7005,state=online,offset=140,lag=0 master_replid:2b20fa4941542dc58d9fc2c32fe6f3dbb6cce72b master_replid2:0000000000000000000000000000000000000000 master_repl_offset:154 second_repl_offset:-1 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:1 repl_backlog_histlen:154 [[email protected] ~]# redis-cli -p 7003 info replication # Replication role:slave master_host:127.0.0.1 master_port:7000 master_link_status:up master_last_io_seconds_ago:6 master_sync_in_progress:0 slave_repl_offset:154 slave_priority:100 slave_read_only:1 connected_slaves:0 master_replid:ad11aa24aa797d942a54550ee77ab0e185e9d92c master_replid2:0000000000000000000000000000000000000000 master_repl_offset:154 second_repl_offset:-1 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:1 repl_backlog_histlen:154 [[email protected] ~]#
9、向redis叢集寫入資料，檢視資料流向
redis-cli -p 7000 -c #這裡會將key自動的重定向，放到某一個節點的slot槽位中
效果如下：
[[email protected] ~]# redis-cli -p 7000 -c 127.0.0.1:7000> keys * (empty list or set) 127.0.0.1:7000> 127.0.0.1:7000> set name felix -> Redirected to slot [5798] located at 127.0.0.1:7001 OK 127.0.0.1:7001> keys * 1) "name" 127.0.0.1:7001>
至此，叢集就搭建好了