Page 1 of 1
Dequeuer in direct mode leaves open cursors
Posted: Thu 11 Feb 2010 16:16
by sebniepel
When using the Dequeuer in Direct Mode and no message is received, it leaves two open cursors on the server.
Using OCI mode the number of cursors do not increase.
Posted: Fri 12 Feb 2010 17:30
by StanislavK
We have reproduced the issue. We will investigate it and notify you about the results.
Posted: Thu 18 Feb 2010 11:51
by schueler
Any updates on this issue?
Posted: Fri 19 Feb 2010 07:24
by StanislavK
I couldn't reproduce the problem with the latest 5.55.97 Beta build. Please try it:
http://www.devart.com/dotconnect/oracle/download.html
If you are still encountering the problem with the new version, please
send us a small test project.
Posted: Mon 01 Mar 2010 12:07
by schueler
Checked with 5.55.97 Beta, but the problem is still there. The following select was used to check for open cursors:
select c.user_name, c.sid, count(*)
from v$open_cursor c, v$sql sql
where c.sql_id = sql.sql_id
group by c.user_name, c.sid
order by count(*) desc;
Posted: Tue 02 Mar 2010 14:42
by StanislavK
Please see the following sample. In our environment, it behaves as described in both Direct and OCI modes:
Code: Select all
// Open the connection.
OracleConnection oracleConnection = new OracleConnection(
//"User Id=Scott;Password=tiger;Server=ora;Direct=False;");
"User Id=Scott;Password=tiger;Server=server;SID=ora;Port=1521;Direct=True;");
oracleConnection.Open();
// Initialize the Queue table and the queue.
OracleQueueTable oracleQueueTable = new OracleQueueTable
("QUEUE_TABLE_MESSAGE", oracleConnection);
oracleQueueTable.Options.PayloadTypeName = "RAW";
OracleQueueAdmin oracleQueueAdmin = new OracleQueueAdmin
("MESSAGE_QUEUE", "QUEUE_TABLE_MESSAGE", oracleConnection);
oracleQueueTable.CreateQueueTable();
oracleQueueAdmin.CreateQueue();
oracleQueueAdmin.StartQueue();
// Create a dequeuing object
OracleQueue oracleDequeueQueue = new OracleQueue("MESSAGE_QUEUE", oracleConnection);
oracleDequeueQueue.DequeueOptions.WaitTimeout = 1;
// Try to dequeue a message. As no messages were enqueued, a timeout exception will be thrown.
// At this moment, several cursors are opened.
try
{
OracleQueueMessage msg = oracleDequeueQueue.Dequeue();
}
catch (OracleException ex)
{
// Check that exception was thrown because of timeout.
if (ex.Code != 25228)
{
throw ex;
}
}
// The cursors are still opened.
oracleConnection.Close();
// The cursors are still opened. They close after the application is terminated.
Please specify if you are encountering a different behaviour when running this sample, or what should be changed in the sample to reproduce the
error.
Also, please note that cursors are not closed after the connection is closed because the
connection pooling feature is enabled. When I disable pooling, the cursors close on oracleConnection.Close().
Posted: Tue 23 Mar 2010 08:58
by sebniepel
Our problem is, if a timeout occurs, we start a new Dequeue(). For that we don`t want to close and reopen the connection. This still leads to open cursors with every loop run. In OCI mode it runs fine.
To reproduce it, just put the try-catch-block in a while loop.
Posted: Tue 23 Mar 2010 16:19
by StanislavK
We have reproduced the problem, inside a loop new cursors are opened till the limit is reached. We will investigate the situation and notify you about the results.
Posted: Wed 31 Mar 2010 16:56
by StanislavK
We have fixed the problem. The fix is available in the new 5.60.120 build of dotConnect for Oracle.
The build can be downloaded from
http://www.devart.com/dotconnect/oracle/download.html
(trial version) or from Registered Users' Area (for users with valid subscription only).
For more information, please refer to
http://www.devart.com/forums/viewtopic.php?t=17514 .