使用MongoDB 3.0版本，部署环境为vSphere构建虚拟机，使用Java driver(3.0.0rc1)多线程写入数据到MongoDB，异常信息如下所示：
Caused by: java.lang.NullPointerException
at com.mongodb.connection.ProtocolHelper.isCommandOk(ProtocolHelper.java:61)
at com.mongodb.connection.WriteCommandProtocol.receiveMessage(WriteCommandProtocol.java:189)
at com.mongodb.connection.WriteCommandProtocol.execute(.java:76)
at com.mongodb.connection.InsertCommandProtocol.execute(InsertCommandProtocol.java:66)
at com.mongodb.connection.InsertCommandProtocol.execute(InsertCommandProtocol.java:37)
at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:155)
at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:219)
at com.mongodb.connection.DefaultServerConnection.insertCommand(DefaultServerConnection.java:108)
at com.mongodb.operation.MixedBulkWriteOperation$Run$2.executeWriteCommandProtocol(MixedBulkWriteOperation.java:416)
at com.mongodb.operation.MixedBulkWriteOperation$Run$RunExecutor.execute(MixedBulkWriteOperation.java:604)
at com.mongodb.operation.MixedBulkWriteOperation$Run.execute(MixedBulkWriteOperation.java:363)
at com.mongodb.operation.MixedBulkWriteOperation$1.call(MixedBulkWriteOperation.java:148)
at com.mongodb.operation.MixedBulkWriteOperation$1.call(MixedBulkWriteOperation.java:141)
at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:186)
at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:177)
at com.mongodb.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:141)
at com.mongodb.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:72)
at com.mongodb.Mongo.execute(Mongo.java:745)
at com.mongodb.Mongo$2.execute(Mongo.java:728)
at com.mongodb.MongoCollectionImpl.executeSingleWriteRequest(MongoCollectionImpl.java:482)
at com.mongodb.MongoCollectionImpl.insertOne(MongoCollectionImpl.java:277)
该异常为偶发性异常，在Windows上，Eclipse环境下，多线程测试，该异常完全不发生，当代码迁移到虚拟服务器上时，该异常偶尔发生；
有大牛遇到过类似情况吗？求教..
