【华为云技术分享】mongos-sharding连接池配置

ShardingTaskExecutorPoolMaxSize

1 Maximum number of outbound connections each TaskExecutor connection pool can open to any given mongod instance. 
2 The maximum possible connections to any given host across all TaskExecutor pools is

连接池最大大小，默认没有限制
对于mongod最大连接控制：ShardingTaskExecutorPoolMaxSize * taskExecutorPoolSize

ShardingTaskExecutorPoolMinSize

Minimum number of outbound connections each TaskExecutor connection pool can open to any given mongod instance.

连接池最小大小，默认为1

taskExecutorPoolSize

1 The number of Task Executor connection pools to use for a given mongos. 
2 The parameter has a minimum value of 4 and a maximum value of 64.

任务池大小，默认是cpu核数

ShardingTaskExecutorPoolMaxConnecting

1 Maximum number of simultaneous initiating connections (including pending connections in setup/refresh state) 
2 each TaskExecutor connection pool can have to a mongod instance. You can set this parameter to control 
3 the rate at which mongos adds connections to a mongod instance.

并发进行初始连接的数量，默认没有限制，该值保持在ShardingTaskExecutorPoolMaxSize以下

ShardingTaskExecutorPoolRefreshRequirementMS

Maximum time the mongos waits before attempting to heartbeat a resting connection in the pool.

连接池保活心跳的间隔时间，默认1分钟

ShardingTaskExecutorPoolRefreshTimeoutMS

Maximum time the mongos waits for a heartbeat before timing out the heartbeat

连接池保活心跳的超时时间，默认20秒

ShardingTaskExecutorPoolHostTimeoutMS

Maximum time that mongos goes without communication to a host before mongos drops all connections to the host.

空闲时间阈值，默认30秒，当mongos与mongod在指定时间内没有交互时会释放连接。

参考文档
https://docs.mongodb.com/v3.4/reference/parameters/#param.ShardingTaskExecutorPoolMaxSize

作者：华为云专家 zale