azure - 空闲后通过 Mongo API 连接到 CosmosDB 失败

Question

我们有一个 Scala 服务器，它使用 Casbah 包装的 Java MongoDB 驱动程序。 。最近，我们使用 Mongo API 将其数据库从实际的 MongoDB 切换到 Azure CosmosDB。这通常工作正常，但是每隔一段时间，对 Cosmos 的调用就会失败并出现 MongoSocketWriteException(堆栈跟踪如下)。

我们正在创建客户端

import com.mongodb.casbah.Imports._

val mongoUrl = "mongodb://username:<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="cfbfaebcbcb8a0bdab8fa7a0bcbbe1aba0acbaa2aaa1bbbce1aeb5babdaae1aca0a2" rel="noreferrer noopener nofollow">[email protected]</a>:10255/?ssl=true&replicaSet=globaldb"

val client = MongoClient(MongoClientURI(mongoUrl))
val collection: MongoCollection = client("mongoDatabase")("mongoCollection")

我们尝试按照针对这个看似相似的错误 ( How to solve MongoError: pool destroyed while connecting to CosmosDB ) 的建议解决方法，从连接 URI 中删除 &replicaSet=globaldb，但它没有解决问题。

堆栈跟踪:

com.mongodb.MongoSocketWriteException: Exception sending message
    at com.mongodb.connection.InternalStreamConnection.translateWriteException(InternalStreamConnection.java:462)
    at com.mongodb.connection.InternalStreamConnection.sendMessage(InternalStreamConnection.java:205)
    at com.mongodb.connection.UsageTrackingInternalConnection.sendMessage(UsageTrackingInternalConnection.java:95)
    at com.mongodb.connection.DefaultConnectionPool$PooledConnection.sendMessage(DefaultConnectionPool.java:424)
    at com.mongodb.connection.CommandProtocol.sendMessage(CommandProtocol.java:209)
    at com.mongodb.connection.CommandProtocol.execute(CommandProtocol.java:111)
    at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:159)
    at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:286)
    at com.mongodb.connection.DefaultServerConnection.command(DefaultServerConnection.java:173)
    at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:215)
    at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:206)
    at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:112)
    at com.mongodb.operation.CountOperation$1.call(CountOperation.java:210)
    at com.mongodb.operation.CountOperation$1.call(CountOperation.java:206)
    at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:230)
    at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:203)
    at com.mongodb.operation.CountOperation.execute(CountOperation.java:206)
    at com.mongodb.operation.CountOperation.execute(CountOperation.java:53)
    at com.mongodb.Mongo.execute(Mongo.java:772)
    at com.mongodb.Mongo$2.execute(Mongo.java:759)
    at com.mongodb.DBCollection.getCount(DBCollection.java:962)
    at com.mongodb.DBCursor.count(DBCursor.java:670)
    at com.mongodb.casbah.MongoCollectionBase.getCount(MongoCollection.scala:496)
    at com.mongodb.casbah.MongoCollectionBase.getCount$(MongoCollection.scala:488)
    at com.mongodb.casbah.MongoCollection.getCount(MongoCollection.scala:1106)
    at com.mongodb.casbah.MongoCollectionBase.count(MongoCollection.scala:897)
    at com.mongodb.casbah.MongoCollectionBase.count$(MongoCollection.scala:894)
    at com.mongodb.casbah.MongoCollection.count(MongoCollection.scala:1106)
    [snip]
Caused by: java.net.SocketException: Broken pipe (Write failed)
    at java.net.SocketOutputStream.socketWrite0(Native Method)
    at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:109)
    at java.net.SocketOutputStream.write(SocketOutputStream.java:153)
    at sun.security.ssl.OutputRecord.writeBuffer(OutputRecord.java:431)
    at sun.security.ssl.OutputRecord.write(OutputRecord.java:417)
    at sun.security.ssl.SSLSocketImpl.writeRecordInternal(SSLSocketImpl.java:876)
    at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:847)
    at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:123)
    at com.mongodb.connection.SocketStream.write(SocketStream.java:75)
    at com.mongodb.connection.InternalStreamConnection.sendMessage(InternalStreamConnection.java:201)
    ... 38 common frames omitted

(发布此问题的答案是因为我希望该解决方案对其他人有用，并且欢迎任何进一步的见解。)

Answer 1

我们将 &maxIdleTimeMS=1500000 添加到连接 URI 以将最大连接空闲时间设置为 25 分钟后，问题就消失了。

原因似乎是 Azure 服务器上的空闲连接超时 30 分钟，而 Mongo 客户端的默认行为根本没有空闲超时。服务器不会向客户端传达它正在断开空闲连接的事实，因此下次尝试使用它会失败并出现上述错误。将最大连接空闲时间设置为小于 30 分钟的值可以使我们的服务器在 Azure 服务器终止空闲连接之前关闭它们。在使用连接之前进行某种类型的保持事件或检查也可能是可能的。

实际上，我还没有找到任何有关 CosmosDB 问题的文档或对此问题的其他引用，尽管它可能是由 Azure 内部负载均衡器的 TCP 连接的 30 分钟空闲超时引起或与之相关(请参阅例如https://feedback.azure.com/forums/217313-networking/suggestions/18823588-increase-idle-timeout-on-internal-load-balancers-t)。