"Invalid attempt to call Read when reader is closed" error (for lengthy operations only)

Question

We have a operation in which more than 100.000 records are read from a csv file and inserted in a database. When I am using a file with 10 records, the operation is completed successfully in less than one minute.

When I use 100.000 records, I am getting the following error “Invalid attempt to call Read when reader is closed.” after 10 minutes. Is there any Timeout that I can configure to avoid this error?

Note: The CommandTimeout is already set as zero.

DbCommand cmd = db.GetStoredProcCommand("aspInsertZipCode");
cmd.CommandTimeout = 0;
dataStringToProcess.Remove(dataStringToProcess.Length - 1, 1);

db.AddInParameter(cmd, "@DataRows", DbType.String, dataStringToProcess.ToString());
db.AddInParameter(cmd, "currDate", DbType.DateTime, DateTime.Now);
db.AddInParameter(cmd, "userID", DbType.Int32, UserID);
db.AddOutParameter(cmd, "CountOfUnchangedZipCode", DbType.String, 1000);

DbDataReader rdr = null;

try
{

    rdr = (DbDataReader)db.ExecuteReader(cmd);
    if (rdr.Read())
    {

        if (!String.IsNullOrEmpty(Utility.GetString(rdr, "NewZipCode")))
            strNewZipCode = strNewZipCode + "," + Utility.GetString(rdr, "NewZipCode");

    }
    rdr.NextResult();
    if (rdr.Read())
    {

        strRetiredZipCode = strRetiredZipCode + "," + Utility.GetString(rdr, "RetiredZipCode");

    }

    int TempUnchageZipCount = Convert.ToInt32(db.GetParameterValue(cmd, "CountOfUnchangedZipCode"));
    CountOfUnchangedZipCode = CountOfUnchangedZipCode + TempUnchageZipCount;
    dataStringToProcess = new StringBuilder();
    cntRec = 0;

}
catch
{
    if (rdr != null && (!rdr.IsClosed))
        rdr.Close();
    throw;
}
finally
{
    if (rdr != null && (!rdr.IsClosed))
        rdr.Close();
}
cmd.Dispose();

I see you are passing the `Reader` around, is it getting closed inside them due to an swallowed exception ? — V4Vendetta, Jul 21 '11 at 11:49

score 2 · Answer 1 · answered Jul 21 '11 at 11:43

2

Could be a database timeout instead... you checked that?

What are you actually trying to do anyway? If you really need to read so many rows perhaps consider reducing it into smaller chunks - say, only read 1000 at a time

answered Jul 21 '11 at 11:43

musefan

47,875
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I checked the DB server. It was set as 600 sec for the Remote Query Timeout. I changed as zero and restarted the server. Still the same error happens. Any other setting that is for 10 min (or 600 sec)? – LCJ Jul 21 '11 at 12:44

score 1 · Accepted Answer · answered Jul 25 '11 at 09:54

1

It was actually MSDTC & Transaction issue. I updated the MSDTC timeout in Component Services. Also I updated timeout values in System.Transactions in machine.config of the application server.

answered Jul 25 '11 at 09:54

LCJ

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67
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"Invalid attempt to call Read when reader is closed" error (for lengthy operations only)

2 Answers2

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