spring-boot3.0.2，如何设置mongodb的最大连接数？

Question

最近在使用mongodb的时候出现一个问题，就是当我连接第10还是第11个的时候，报错，只要我关闭一个服务再启动就是好的，所以我怀疑是跟连接数有关，但是我设置了不起作用，下面是我设置的两种写法，都试了都不行！有谁知道如何解决不？
方式一：

    mongodb:
      uri: mongodb://xxx:[e-mail]:3717/dev?retryWrites=true&connectTimeoutMS=10000&authSource=admin&authMechanism=SCRAM-SHA-1&maxPoolSize=20

方式二：

    mongodb:
      host: xxx.xxx.xxx.xxx
      port: 3717
      username: xxx
      password: xxx
      database: dev
      authentication-database: admin
      option:
        socket:
          connectTimeout: 30000
          readTimeout: 10000
        pool:
          # 设置最大连接数
          maxPoolSize: 80
          minPoolSize: 0
          maxWaitTime: 5000
          maxConnectionLifeTime: 600000
          maxConnectionIdleTime: 30000

下面是报的错：

2023-07-11T13:47:37.500+08:00  INFO 35602 --- [iyuncs.com:3717] org.mongodb.driver.cluster               : Exception in monitor thread while connecting to server xxx.xxx.xxx.xxx:3717

com.mongodb.MongoSocketReadException: Exception receiving message
        at com.mongodb.internal.connection.InternalStreamConnection.translateReadException(InternalStreamConnection.java:705) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.InternalStreamConnection.receiveMessageWithAdditionalTimeout(InternalStreamConnection.java:577) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.InternalStreamConnection.receiveCommandMessageResponse(InternalStreamConnection.java:413) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.InternalStreamConnection.sendAndReceive(InternalStreamConnection.java:340) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.CommandHelper.sendAndReceive(CommandHelper.java:104) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.CommandHelper.executeCommand(CommandHelper.java:48) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.InternalStreamConnectionInitializer.initializeConnectionDescription(InternalStreamConnectionInitializer.java:134) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.InternalStreamConnectionInitializer.startHandshake(InternalStreamConnectionInitializer.java:76) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.InternalStreamConnection.open(InternalStreamConnection.java:185) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.lookupServerDescription(DefaultServerMonitor.java:198) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.internal.connection.DefaultServerMonitor$ServerMonitorRunnable.run(DefaultServerMonitor.java:158) ~[mongodb-driver-core-4.8.2.jar:na]
        at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]
Caused by: java.io.IOException: The connection to the server was closed
        at com.mongodb.connection.netty.NettyStream$OpenChannelFutureListener$1.operationComplete(NettyStream.java:511) ~[mongodb-driver-core-4.8.2.jar:na]
        at com.mongodb.connection.netty.NettyStream$OpenChannelFutureListener$1.operationComplete(NettyStream.java:508) ~[mongodb-driver-core-4.8.2.jar:na]
        at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:590) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:557) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:492) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.DefaultPromise.setValue0(DefaultPromise.java:636) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.DefaultPromise.setSuccess0(DefaultPromise.java:625) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.DefaultPromise.trySuccess(DefaultPromise.java:105) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.DefaultChannelPromise.trySuccess(DefaultChannelPromise.java:84) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.AbstractChannel$CloseFuture.setClosed(AbstractChannel.java:1164) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.AbstractChannel$AbstractUnsafe.doClose0(AbstractChannel.java:755) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.AbstractChannel$AbstractUnsafe.close(AbstractChannel.java:731) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.AbstractChannel$AbstractUnsafe.close(AbstractChannel.java:620) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.closeOnRead(AbstractNioByteChannel.java:105) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:174) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:788) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.87.Final.jar:4.1.87.Final]
        ... 1 common frames omitted

Answer 1

找到原因了：阿里云Mongodb预设的最大连接数50已经满了

Answer 2

你的第一种方式是对的，但是你要保证你的MongoDB服务器支持你设置的最大连接数。如果你的MongoDB服务器的最大连接数小于你设置的值，那你的设置可能不会生效。