We have just published updates to address the scalability issues in Team System Web Access 2008 power tool.

The update consists of two parts that can be installed separately, but I strongly recommend installing both updates to get the most benefits for improved scalability:

1. Patch for referenced object model assemblies

This update contains fixes in various assemblies used by Web Access, Team Explorer and Team Foundation Server.

You can download it at:

You need to install this patch to the server where Web Access 2008 power tool is running. Important: Make sure you run the patch using an account different than the service account that TFS runs as.

2. Web Access 2008 power tool:

This is a full release that contains the latest version of Web Access 2008 power tool with the scalability fixes.

You can download it at:

You need to uninstall any existing installations of Web Access 2008 before installing this.

 

What was the problem?

Due to a couple of bugs in Web Access and TFS object model assemblies, certain objects in memory were not properly released when they are no longer used, which resulted in memory leaks.

When Web Access 2008 was accessed by multiple people over a certain period of time, the memory consumption increased linearly to a point where Web Access application became unstable due to the fact that there’s no sufficient memory to handle new requests. In some cases, IIS might automatically force a app pool recycle due to the memory pressure, causing all logged in users to be kicked out with error messages saying the sessions have timed out.

Along with that, you might have seen common error messages like “unable to create work item store” which are actually a manifestation of the underlying “out of memory” exceptions.

What is the fix?

This update fixes the known memory leaks in both Web Access and TFS object model assemblies so that the Web Access instance does not destabilize over time.

What can I expect from this fix?

The most important improvement is the stability of Web Access over time. Previously -in theory- even a single user could cause scalability issues over a long period of time due to the nature of the memory leaks, and this is no longer the case.

If you install both updates, you will see improvements with the stability of Web Access instance, especially if you have multiple people using it for long periods of time. In summary, the frequency of session timeout or “unable to create work item store” errors will decrease dramatically.

How does this fix change the scalability limits of Web Access 2008?

Although the number of concurrent users that Web Access can handle is somehow improved with this update, the biggest improvement is the stability over time as I explained in the previous section. That said, I’m planning to update the TSWA 2008 Scalability Limits Whitepaper soon so watch this blog for updates.