Issue with Webflow during load

[Mridul]

Hi, We have a web based application which under load gives error like
org.springframework.webflow.execution.repository.s napshot.SnapshotNotFoundException: No flow execution snapshot could be found with id 'e1s2".'4'; perhaps the snapshot has been removed?

Wanted to poll the group to check if any one else has faced similar issue and how have they resolved it.

Thanks
Mridul

[InverseFalcon]

Under load...is this a load test, or is this currently in production?

I assume you're aware of SWF's snapshot mechanism, and how snapshots are cleaned up as you hit the max number of snapshots? Likewise, are you aware of the max number of executions in your flow config file?

With these things in mind, do you know what the users are doing when this occurs? Are they opening up links in separate windows or tabs? Are they bookmarking and attempting to jump back to previous pages in the flow? Are they using the browser back button or history?

If you're performing load testing, are you using the same user/session for all requests? Are you using the same execution ID for all requests on the same session? I suspect you'll run into trouble if you are.

In any case, the more you can provide, the better. I also suggest searching through the forums looking for "snapshot" or similar terms if you are not already aware of how SWF saves (and cleans up) snapshots.

[Mridul]

Appreciate the response, InverseFalcon.

The issue is currently happening under load test scenario using Jmeter. We did try option of clearing cookie with every test but it still seems to be an issue.

Users are following particular flow i.e. clicking on certain links to follow to next page and not opening any new window as this is through Jmeter load testing tool.

I have not configured any number of snapshot or executions so it should take the default value.

I did try to look around forum for how SWF saves snapshot but it still seems not very clear.

[tiger.spring]

Mridul,

This article should help you... http://www.ervacon.com/products/swf/tips/tip2.html

[tiger.spring]

Mridual, since you are performing load test for Spring Web Flow may I ask for how many concurrent users you are testing the application?

Basically, I'm interested in knowing if Spring Web Flow is a good choice for large number of concurrent users because it stores everything into HTTP Session object until the flow has reached it's end state?