Querying the database throw an exception

Question

When I return about 200,000 records to client the service works fine. But increasing the returned data(to 1 million) set causes below exception on server side:

System.InvalidOperationException: Server instance localhost:xxxx is no longer connected. 
at MongoDB.Driver.MongoServerInstance.AcquireConnection(MongoDatabase database) 
in C:\work\10gen\mongodb\mongo-csharp driver\Driver\Core\MongoServerInstance. cs:line 288

Somewhat happened when querying the database. I have the latest MongoDb driver. ConnectionPoolSize = 900 ConnectionTimeoutSeconds = 3000

what purpose does returning 1000000 records serve? It's not human-readable. Return your results in batches. — user1666620, Sep 29 '15 at 13:04

score 2 · Accepted Answer · edited May 23 '17 at 12:14

2

Read your data in smaller chunks/pages. See this question for more information:

MongoDB - paging

In short, you can do something like this:

int currentOffset = 0;
int recordsFetched;
do
{
    var results =
        collection.Find(query)
                  .SetSkip(currentOffset)
                  .SetLimit(100)
                  .ToList();

    currentOffset += 100;
    recordsFetched = results.Count;

    // Process your data here.
} while(recordsFetched > 0);

edited May 23 '17 at 12:14

Community

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answered Sep 29 '15 at 13:07

Dmytro Shevchenko

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Do you now how to do this? – Anatoly Sep 29 '15 at 13:17

Querying the database throw an exception

1 Answers1