MongoDB 副本集 - 心跳请求错误

Question

我在本地创建了 mongo db 副本集，如下所示：

    mongod --port 27021 --dbpath /cm1/mongodb/rs0-1 --replSet rs0 --smallfiles --oplogSize 128.

我已经开始的所有3（1主，次级2）的实例与mongo --port 27022。

副本集正在工作，数据从主节点流向辅助节点。

如果我关闭 mongodb 实例之一，其余 2 个实例会抛出错误。日志如下：

2017-07-25T13:01:24.904+0530 I REPL     [ReplicationExecutor] Error in heartbeat request to localhost:27021; HostUnreachable: Connection refused
2017-07-25T13:01:24.904+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Connecting to localhost:27021
2017-07-25T13:01:24.906+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Failed to connect to localhost:27021 - HostUnreachable: Connection refused
2017-07-25T13:01:24.906+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Dropping all pooled connections to localhost:27021 due to failed operation on a connection
2017-07-25T13:01:24.906+0530 I REPL     [ReplicationExecutor] Error in heartbeat request to localhost:27021; HostUnreachable: Connection refused
2017-07-25T13:01:24.906+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Connecting to localhost:27021
2017-07-25T13:01:24.907+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Failed to connect to localhost:27021 - HostUnreachable: Connection refused
2017-07-25T13:01:24.907+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Dropping all pooled connections to localhost:27021 due to failed operation on a connection
2017-07-25T13:01:24.907+0530 I REPL     [ReplicationExecutor] Error in heartbeat request to localhost:27021; HostUnreachable: Connection refused
2017-07-25T13:01:26.908+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Connecting to localhost:27021
2017-07-25T13:01:26.910+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Failed to connect to localhost:27021 - HostUnreachable: Connection refused
2017-07-25T13:01:26.910+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Dropping all pooled connections to localhost:27021 due to failed operation on a connection
2017-07-25T13:01:26.910+0530 I REPL     [ReplicationExecutor] Error in heartbeat request to localhost:27021; HostUnreachable: Connection refused
2017-07-25T13:01:26.910+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Connecting to localhost:27021
2017-07-25T13:01:26.911+0530 I ASIO     [NetworkInterfaceASIO-Replication-0] Failed to connect to localhost:27021 - HostUnreachable: Connection refused

关闭实例时是否缺少副本？

Answer 1

其实没有！如果您关闭副本集中的一个节点，其他节点当然会开始抱怨它们无法连接那个丢失的节点。所有节点总是相互“交谈”。

错误消息表明，丢失的节点位于端口 27021 中。