Redis集群新增、删除节点以及动态增加内存的方法

cp redis7001.conf redis7002.conf

cd ../bin/
./redis-server ../etc/redis7002.conf

./redis-cli --cluster add-node 127.0.0.3:7002 127.0.0.1:7002
./redis-cli --cluster add-node 127.0.0.4:7002 127.0.0.1:700

redis-cli -c -h 192.168.8.196 -p 5008

cluster replicate 1f42f45cd136239d95fc15bda9938821c33138cc

./redis-cli --cluster reshard 127.0.0.5:7002

How many slots do you want to move (from 1 to 16384)? 4096

#它提示我们需要迁移多少slot到7007上，我们平分16384个哈希槽给4个节点：16384/4 = 4096，我们需要移动4096个槽点到7007上。
#ps:这里分配可以根据你新增的节点内存和已存在的节点进行考虑，新增节点内存大可以相对分配的多点

What is the receiving node ID? 63aa476d990dfa9f5f40eeeaa0315e7f9948554d
#这里添加接收节点的ID，我们填写127.0.0.5:7002服务节点的ID
1.Please enter all the source node IDs.
2.Type ‘all' to use all the nodes as source nodes for the hash slots.
3.Type ‘done' once you entered all the source nodes IDs.
4.Source node #1: 
#redis-trib 会向你询问重新分片的源节点（source node），即，要从特点的哪个节点中取出 4096 个哈希槽，还是从全部节点提取4096个哈希槽， 并将这些槽移动到7007节点上面。
#如果我们不打算从特定的节点上取出指定数量的哈希槽，那么可以向redis-trib输入 all，这样的话， 集群中的所有主节点都会成为源节点，redis-trib从各个源节点中各取出一部分哈希槽，凑够4096个，然后移动到7007节点上：
1.Source node #1:all  
然后开始从别的主节点迁移哈希槽，并且确认。
....省略分配内容
1.Do you want to proceed with the proposed reshard plan (yes/no)? yes 
#注意这里一定要输入yes，输入Y或者其他会终止操作。 
#确认之后，redis-trib就开始执行分片操作，将哈希槽一个一个从源主节点移动到127.0.0.5:7002目标主节点。

./redis-trib.rb check 127.0.0.1:7001
...省略节点内容
#可以看到7007节点分片的哈希槽片不是连续的，间隔的移动。

./redis-cli --cluster del-node 127.0.0.6 3bc21c09f3318342600205b1b5e6ea129e3608f3

./redis-cli --cluster reshard 127.0.0.5:7002

1、How many slots do you want to move (from 1 to 16384)? 4461
2、What is the receiving node ID? b7e55a3d3eda2777c077c606c090bcfaf6b674fd
#这一步是问要将这些slot槽分配到哪个节点上，我分配到了127.0.0.1:7002上，所以填写它的ID
3、Please enter all the source node IDs.
  3.1、Type 'all' to use all the nodes as source nodes for the hash slots.
  3.2、Type 'done' once you entered all the source nodes IDs.
3.3、Source node #1:
#这里需要数据源，其实就是 127.0.0.5:7002 节点的ID，因为你是把 7002 节点的数据放到其它地方去， 输入 7002 的ID
#回车之后会出现再次输入id
#其实是让你还可以选择源节点，但是我这里只要把 7002 节点分到其它地方就行，如果没有再把其它主节点分摊的需要，此处输入 done即可，否则输入其它节点的ID，最后输入 done
4.Do you want to proceed with the proposed reshard plan (yes/no)? yes 
#注意这里一定要输入yes，输入Y或者其他会终止操作。 
#这里就分配完slot槽了

./redis-cli --cluster del-node 127.0.0.6 主节点ID

redis 127.0.0.1:7002> config get maxmemory
1) "maxmemory"
2) "5000000000"

redis 127.0.0.1:6379> config set maxmemory 10G
OK
#其实set 10G是不规范的，最好的是换算下填写10737418240

redis 127.0.0.1:6379> CONFIG GET maxmemory
1) "maxmemory"
2) "10000000000"

127.0.0.1:6379> CONFIG GET *
 1) "dbfilename"
  2) "dump.rdb"
  3) "requirepass"
  4) "123456"
  5) "masterauth"
  6) ""
  7) "unixsocket"
  8) ""
  9) "logfile"
 10) "/diskc/redis-2.8.19/log/6379_slave.log"
 11) "pidfile"
 12) "/var/run/redis.pid"
 13) "maxmemory"
 14) "10000000000"
 15) "maxmemory-samples"
 16) "3"
 17) "timeout"
 18) "0"
 19) "tcp-keepalive"
 20) "0"
 21) "auto-aof-rewrite-percentage"
 22) "100"
 23) "auto-aof-rewrite-min-size"
 24) "67108864"
 25) "hash-max-ziplist-entries"
 26) "512"
 27) "hash-max-ziplist-value"
 28) "64"
 29) "list-max-ziplist-entries"
 30) "512"
 31) "list-max-ziplist-value"
 32) "64"
 33) "set-max-intset-entries"
 34) "512"
 35) "zset-max-ziplist-entries"
 36) "128"
 37) "zset-max-ziplist-value"
 38) "64"
 39) "hll-sparse-max-bytes"
 40) "3000"
 41) "lua-time-limit"
 42) "5000"
 43) "slowlog-log-slower-than"
 44) "100000"
 45) "latency-monitor-threshold"
 46) "0"
 47) "slowlog-max-len"
 48) "128"
 49) "port"
 50) "6379"
 51) "tcp-backlog"
 52) "511"
 53) "databases"
 54) "16"
 55) "repl-ping-slave-period"
 56) "10"
 57) "repl-timeout"
 58) "60"
 59) "repl-backlog-size"
 60) "1048576"
 61) "repl-backlog-ttl"
 62) "3600"
 63) "maxclients"
 64) "15000"
 65) "watchdog-period"
 66) "200"
 67) "slave-priority"
 68) "100"
 69) "min-slaves-to-write"
 70) "0"
 71) "min-slaves-max-lag"
 72) "10"
 73) "hz"
 74) "10"
 75) "repl-diskless-sync-delay"
 76) "5"
 77) "no-appendfsync-on-rewrite"
 78) "no"
 79) "slave-serve-stale-data"
 80) "yes"
 81) "slave-read-only"
 82) "yes"
 83) "stop-writes-on-bgsave-error"
 84) "yes"
 85) "daemonize"
 86) "yes"
 87) "rdbcompression"
 88) "yes"
 89) "rdbchecksum"
 90) "yes"
 91) "activerehashing"
 92) "yes"
 93) "repl-disable-tcp-nodelay"
 94) "no"
 95) "repl-diskless-sync"
 96) "no"
 97) "aof-rewrite-incremental-fsync"
 98) "yes"
 99) "aof-load-truncated"
100) "yes"
101) "appendonly"
102) "no"
103) "dir"
104) "/diskc/redis-2.8.19"
105) "maxmemory-policy"
106) "volatile-lru"
107) "appendfsync"
108) "everysec"
109) "save"
110) "900 1 300 10 60 10000"
111) "loglevel"
112) "notice"
113) "client-output-buffer-limit"
114) "normal 0 0 0 slave 268435456 67108864 60 pubsub 33554432 8388608 60"
115) "unixsocketperm"
116) "0"
117) "slaveof"
118) ""
119) "notify-keyspace-events"
120) ""
121) "bind"
122) ""