HTTP GET

Ran into a nasty problem with one of our webapps recently.

We have some jobs that enable and disable a number of weblogic entities (OSB proxies/ JMS queue/ Soa Composites). We noticed that some of these were failing.

The exception we saw was ERROR: Another session operation is in progress. Please retry later.

As part of our process (to disable OSB proxies) we need to create and use a weblogic session. We only create one instance, and then activate the changes at the end. But in our logs a 2^nd session was been created.

After careful inspection it turned out the second session was been generated by a different thread. Checking the access.log confirmed a 2^nd request arriving 30 seconds after the first. (This maybe certain versions of Firefox.. Need more investigation)

This it appears is because we were using a HTTP Get (we should be using Post) for our request. Apparently on seeing no response/ ack etc, the browser was re-submiting the request on its own accord.

So now we had 2 conflicting requests both trying to access the weblogic session. Obviously the 2^nd fails. This was then reported to the user.

Meanwhile the original request succeeds silently.

Our fix is to change the request to a post.

Also adding a token to the post request to prevent against double submit.

….

2011-01-18 20:51:21,335 [DEBUG] myClass:[ACTIVE] ExecuteThread: '3' for queue: 'weblogic.kernel.Default (self-tuning)':- Realizing changes in the session: WebAdminTool1295383871917

2011-01-18 20:51:21,759 [DEBUG] myClass:[ACTIVE] ExecuteThread: '3' for queue: 'weblogic.kernel.Default (self-tuning)':- Setting service OSBProxy::false to true

2011-01-18 20:51:28,551 [INFO ] ie.bge.middleware.jmswebtool.data.impl.jmx.QueuePersistenceJmxImpl:[ACTIVE] ExecuteThread: '4' for queue: 'weblogic.kernel.Default (self-tuning)':- Result from pauseConsumption: null

2011-01-18 20:51:28,554 [INFO ] ie.bge.middleware.jmswebtool.data.impl.jmx.QueuePersistenceJmxImpl:[ACTIVE] ExecuteThread: '4' for queue: 'weblogic.kernel.Default (self-tuning)':- Result from pauseConsumption: null

...

2011-01-18 20:51:28,644 [DEBUG] myClass :[ACTIVE] ExecuteThread: '4' for queue: 'weblogic.kernel.Default (self-tuning)':- Creating new Weblogic session WebAdminTool1295383888606

2011-01-18 20:51:48,669 [ERROR] myClass:[ACTIVE] ExecuteThread: '4' for queue: 'weblogic.kernel.Default (self-tuning)':- ERROR: Another session operation is in progress. Please retry later.

...

2011-01-18 20:51:58,571 [DEBUG] myClass:[ACTIVE] ExecuteThread: '3' for queue: 'weblogic.kernel.Default (self-tuning)':- Activated changes in the session: WebAdminTool1295383871917