Redisson报错：Unable to write command into connection! Increase connection pool size，集群出错

本文介绍: 本身redis–server也是默认只在主节点读写，如果用redis–cli 连接就能发现，读写任何key都会自动跳转到主节点，而不会在从节点。看153的redis–server 日志，错误日志，157是报错从节点对应的主节点：说明从节点连不上主节点。但redisson 配置的是从节点读、主节点写，所以导致加锁执行 exists 命令时到问题节点读取失败。解决方式，把redisson 配置为主节点读写，不在从节点读，去除从节点不稳定的影响。场景：使用 redisson锁，redis–server是集群方式，三主三从。

场景：使用 redisson锁，redis–serve r是集群方式，三主三从

错误信息有：

Una ble t o write command into connection! Inc re a s e connection pool size. Node source: NodeSour ce [slot=5073, addr=null, redi sClient=null, re direct=null, entry=null], connection: Redi sConne ct ion@1161754400 [redi sCli ent=[addr=redis://172.21.75.153:6379], channel=[id: 0x8490cd34, L:0.0.0.0/0.0.0.0:33988 ! R:172.21.75.153/172.21.75.153:6379], currentComm and=null, usa g e=1], com m and: (EXISTS), params: [red isLoc k _serviceLoc k] aft er 3 retry attempts

org.redisson.client.Re disConne ct ionExc ept ion: Slav eConn ectionPool no av ai lable Redis entr i es. Master entry host: 172.21.75.157/172.21.75.157:6379 Disconnected hosts: [172.21.75.157/172.21.75.157:6379] Hos ts disconnected due to errors d uring `failedSlaveCh ec kInterval`: [172.21.75.153/172.21.75.153:6379]

org.redisson.client.RedisConn ectionExc ept ion: SlaveConn ectionPool no available Redis entries. Master entry host: 172.21.75.157/172.21.75.157:6379 Disconnected hosts: [172.21.75.157/172.21.75.157:6379, 172.21.75.153/172.21.75.153:6379]

redisson 官方 github让升级版本，但这已经是20版本。

3759119:S 06 May 2023 13:43:04.123 # Cluster state changed: fail
3759119:S 06 May 2023 13:43:42.325 # MASTER timeout: no data nor PING received...
3759119:S 06 May 2023 13:43:42.325 # Connection with master lost.
3759119:S 06 May 2023 13:43:42.325 * Caching the disconnected master state.
3759119:S 06 May 2023 13:43:42.325 * Connecting to MASTER 172.21.75.157:6379
3759119:S 06 May 2023 13:43:42.325 # Unable to connect to MASTER: Network is unreachable
3759119:S 06 May 2023 13:43:43.327 * Connecting to MASTER 172.21.75.157:6379
3759119:S 06 May 2023 13:43:43.327 # Unable to connect to MASTER: Network is unreachable
3759119:S 06 May 2023 13:43:44.329 * Connecting to MASTER 172.21.75.157:6379
3759119:S 06 May 2023 13:43:44.329 # Unable to connect to MASTER: Network is unreachable
3759119:S 06 May 2023 13:43:45.331 * Connecting to MASTER 172.21.75.157:6379
3759119:S 06 May 2023 13:43:45.331 # Unable to connect to MASTER: Network is unreachable

BaseConfig baseConfig;
baseConfig = config.setCodec(JsonJacksonCodec.INSTANCE)
                            .useClusterServers().addNodeAddress(xxx)
                    .setReadMode(ReadMode.MASTER)