Mongodb Java驱动程序无法偶尔读取数据，套接字超时

我正在尝试使用Mongodb java驱动程序，我对这个偶尔出现的错误感到非常失望，尽管最常见的错误是在我第一次尝试连接数据库时出现的。任何关于去哪里找的帮助都会非常有用

设置基本上是这样的：我在本地主机上启动Play 2.0应用程序，尝试在我的应用程序上注册用户。当我键入用户名时，会向数据库发送一个查询以检查用户名是否存在，这需要一秒钟的时间（可能是实例化Mongo singleton和连接到数据库的开销），但似乎可以工作，我可以像这样成功执行多个查询：

public static boolean usernameIsAvailable(String username){
    DBCollection users = DBManager.getDB("mojulo").getCollection("users");
    DBCursor cursor = users.find(new BasicDBObject("username", username));
    if(cursor.count() == 0)
        return true;
    return false;
}

然后，当我尝试插入用户（总共约2kb的数据）时，问题出现了：

这会偶尔失败，但在

if（result.getLastError（）.ok（））

行中往往会失败。我无法真正了解这个问题，因为它会随机弹出。以下是堆栈跟踪的一般外观：

play.core.ActionInvoker$$anonfun$receive$1$$anon$1: Execution exception [[Network: can't call something : ds033307.mongolab.com/107.20.129.238:33307/heroku_app4620908]]
at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:82) [play_2.9.1.jar:2.0]
at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:63) [play_2.9.1.jar:2.0]
at akka.actor.Actor$class.apply(Actor.scala:290) [akka-actor.jar:2.0]
at play.core.ActionInvoker.apply(Invoker.scala:61) [play_2.9.1.jar:2.0]
at akka.actor.ActorCell.invoke(ActorCell.scala:617) [akka-actor.jar:2.0]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:179) [akka-actor.jar:2.0]

Caused by: com.mongodb.MongoException$Network: can't call something : ds033307.mongolab.com/107.20.129.238:33307/heroku_app4620908
at com.mongodb.DBTCPConnector.call(DBTCPConnector.java:227) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:305) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DB.command(DB.java:160) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DB.command(DB.java:183) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DBCollection.getCount(DBCollection.java:864) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DBCollection.getCount(DBCollection.java:835) ~[mongo-java-driver-2.7.3.jar:na]

Caused by: java.net.SocketException: Operation timed out
at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.6.0_31]
at java.net.SocketInputStream.read(SocketInputStream.java:129) ~[na:1.6.0_31]
at java.io.BufferedInputStream.fill(BufferedInputStream.java:218) ~[na:1.6.0_31]
at java.io.BufferedInputStream.read1(BufferedInputStream.java:258) ~[na:1.6.0_31]
at java.io.BufferedInputStream.read(BufferedInputStream.java:317) ~[na:1.6.0_31]
at org.bson.io.Bits.readFully(Bits.java:35) ~[mongo-java-driver-2.7.3.jar:na]

任何帮助都将不胜感激，因为我真的不知道这里发生了什么，更有经验的人可能知道去哪里找

有一点可能也说明了这一点，那就是问题发生的频率越高，我尝试加载到保存对象中的数据越多

---

谢谢

而不是users.find（新的BasicDBObject（“email”，email））；您可以尝试使用users.find（新的BasicDBObject（“email”，email））.isExist（）；

isExist

方法似乎不存在。在findOne上（查询）不在find上。返回光标不会有什么区别。。。另外，我认为我这样做（返回光标并检查计数）意味着所有用户的数据最终都不会通过电线传输。除非我弄错了。但是，当我们遇到这样的情况时，例如任何具有相同emailid的用户，findOne（query）.isExist（）将在一行中完成您的工作。

play.core.ActionInvoker$$anonfun$receive$1$$anon$1: Execution exception [[Network: can't call something : ds033307.mongolab.com/107.20.129.238:33307/heroku_app4620908]]
at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:82) [play_2.9.1.jar:2.0]
at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:63) [play_2.9.1.jar:2.0]
at akka.actor.Actor$class.apply(Actor.scala:290) [akka-actor.jar:2.0]
at play.core.ActionInvoker.apply(Invoker.scala:61) [play_2.9.1.jar:2.0]
at akka.actor.ActorCell.invoke(ActorCell.scala:617) [akka-actor.jar:2.0]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:179) [akka-actor.jar:2.0]

Caused by: com.mongodb.MongoException$Network: can't call something : ds033307.mongolab.com/107.20.129.238:33307/heroku_app4620908
at com.mongodb.DBTCPConnector.call(DBTCPConnector.java:227) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:305) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DB.command(DB.java:160) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DB.command(DB.java:183) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DBCollection.getCount(DBCollection.java:864) ~[mongo-java-driver-2.7.3.jar:na]
at com.mongodb.DBCollection.getCount(DBCollection.java:835) ~[mongo-java-driver-2.7.3.jar:na]

Caused by: java.net.SocketException: Operation timed out
at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.6.0_31]
at java.net.SocketInputStream.read(SocketInputStream.java:129) ~[na:1.6.0_31]
at java.io.BufferedInputStream.fill(BufferedInputStream.java:218) ~[na:1.6.0_31]
at java.io.BufferedInputStream.read1(BufferedInputStream.java:258) ~[na:1.6.0_31]
at java.io.BufferedInputStream.read(BufferedInputStream.java:317) ~[na:1.6.0_31]
at org.bson.io.Bits.readFully(Bits.java:35) ~[mongo-java-driver-2.7.3.jar:na]