MongoDB Connection Reset

[Chong Wang]

I am trying to download millions of records from a remote DB (Amazon RedShift) into a local MongoDB database (3.0.2). However, an exception sometimes occurs as below. 

>Processing up to User 180000
>Sent SQL to RedShift for retrieving individual users' logs
>Received individual users' logs successfully
>Inserting to local MongoDB...

Exception in thread "main" com.mongodb.MongoException$Network: Connection reset
    at com.mongodb.WriteResult.getLastError(WriteResult.java:96)
    at com.mongodb.WriteResult.getLastError(WriteResult.java:73)
    at com.mongodb.WriteResult.getField(WriteResult.java:141)
    at com.mongodb.WriteResult.getError(WriteResult.java:118)
    at edu.njit.mongodb.MongoDBManager.insertOneLog(MongoDBManager.java:46)
    at edu.njit.userlog.FreqUserLogDownloader.queryIndividualUserLog(FreqUserLogDownloader.java:122)
    at edu.njit.userlog.FreqUserLogDownloader.main(FreqUserLogDownloader.java:158)
Caused by: java.net.SocketException: Connection reset
    at java.net.SocketInputStream.read(Unknown Source)
    at java.net.SocketInputStream.read(Unknown Source)
    at java.io.BufferedInputStream.fill(Unknown Source)
    at java.io.BufferedInputStream.read1(Unknown Source)
    at java.io.BufferedInputStream.read(Unknown Source)
    at org.bson.io.Bits.readFully(Bits.java:46)
    at org.bson.io.Bits.readFully(Bits.java:33)
    at org.bson.io.Bits.readFully(Bits.java:28)
    at com.mongodb.Response.<init>(Response.java:40)
    at com.mongodb.DBPort.go(DBPort.java:124)
    at com.mongodb.DBPort.go(DBPort.java:88)
    at com.mongodb.DBPort.findOne(DBPort.java:143)
    at com.mongodb.DBPort.runCommand(DBPort.java:148)
    at com.mongodb.DBPort.getLastError(DBPort.java:138)
    at com.mongodb.DBPort.tryGetLastError(DBPort.java:171)
    at com.mongodb.WriteResult.getLastError(WriteResult.java:94)
    ... 6 more

The MongoDB log shows (I am sorry that I do not keep the whole log): 

***aborting after fassert() failure

The "edu.njit.mongodb.MongoDBManager.insertOneLog(MongoDBManager.java:46)" refers to my code:

public void insertOneLog(ResultSet rs) throws SQLException {
    BasicDBObject doc = new BasicDBObject();
    doc.put( "uid", rs.getString( "uid" ) );
    doc.put( "url", rs.getString( "url" ) );
    doc.put( "additionalinfo", reformatAddiInfo( rs.getString( "additionalinfo" ) ) );

    WriteResult wr = coll.insert( doc );
    if(wr.getError() != null) // This is the Line 46
        System.err.println("Fail To Insert: " + wr.getError());
}

I am wondering the reason of this exception and how I can avoid it. 

Thanks!