java - mongoDB:游标 notimeout 设置在 java 客户端中不起作用

Question

我在 java 中为 dbcursor 设置了一个 'notimeout' 选项:

    BasicDBObject nearbyQueries = new BasicDBObject("$gt", 0)
            .append("$lte", 2);
    DBCursor trueClassInstances = locationsCollection.find(new BasicDBObject("distanceFromHotel", nearbyQueries)).addOption(Bytes.QUERYOPTION_NOTIMEOUT).limit(100000);
    double counter = 0;
    int currentPresent = 0;
    for (DBObject instance : trueClassInstances) {

        ...
    }

即使我设置了这个选项，也会抛出这个异常:

Exception in thread "main" com.mongodb.MongoCursorNotFoundException: Query failed with error code -5 and error message 'Cursor 1876954464377 not found on server XXXXXX:27017' on server XXXXXXXX:27017
    at com.mongodb.connection.GetMoreProtocol.receiveMessage(GetMoreProtocol.java:115)
    at com.mongodb.connection.GetMoreProtocol.execute(GetMoreProtocol.java:68)
    at com.mongodb.connection.GetMoreProtocol.execute(GetMoreProtocol.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.getMore(DefaultServerConnection.java:194)
    at com.mongodb.operation.QueryBatchCursor.getMore(QueryBatchCursor.java:197)
    at com.mongodb.operation.QueryBatchCursor.hasNext(QueryBatchCursor.java:93)
    at com.mongodb.MongoBatchCursorAdapter.hasNext(MongoBatchCursorAdapter.java:46)
    at com.mongodb.DBCursor.hasNext(DBCursor.java:152)
    at locationExtraction.DistanceClassification.FeatureAnalyzer.main(FeatureAnalyzer.java:27)

FeatureAnalyzer.java:27 是 for 循环行。

此问题出现在其他具有类似设置的项目中...

我做错了什么？也许我选择“for”循环而不是这种迭代会导致这种奇怪的行为？

while(cursor.hasNext())
{
      DBObject next = cursor.next();
}

谢谢

Answer 1

您似乎无法在时限内处理每个批处理。尝试减少批处理大小，以便在时间用完之前消耗每个批处理。这应该会有所帮助。
cursor.addOption(com.mongodb.Bytes.QUERYOPTION_NOTIMEOUT).batchSize(100)