Exchange 2010 OWA Hangs

Posted By jdewing on 05/27/2011 05:06 AM

 

Jerry,

 

 

I had a similar issue. By unchecking "Keep Accept Encoding" from the http profile, errors with javascripts disappeared. OWA no longer will hang.

 

 

Jamie

 

You were still doing compression on the F5, right? Just to explain further, the Keep Accept-Encoding option is meant to control whether Accept-Encoding header, which controls whether client is able to do compression or not, is passed on to the server. By default, F5 will strip Accept-Encoding header if it is doing compression, from the request that is forwarded on to the server to prevent server from compressing content. Pretty much any application that leverages F5 for doing compression should have Keep Accept Encoding box unchecked.

 

JTrimble - No problem, so far I'm not having any issue when I disabled the "Keep accept Encoding". We have been in the production mode for about 2 months now with ~4,000 employee

 

 

Michael - Yes, we are doing compression on F5 and with Nagle's Algorthitm disabled, OWA performance increased

 

 

 

 

 

 

I am currently using two VIPs - one for HTTP services and one for RPC. I am also seeing issues with OWA hanging. The problem is we ARE using ActiveSync. Or at least will be. How will unchecking the "keep accept" affect ActiveSync traffic? If it will adversly impact ActiveSync traffic, it's sounding like we need to deploy another VIP. Are there any other options that the deployment guide has wrong?

Michael,

 

 

By disabling "Keep accept Encoding" on the HTTP profile for the VS, the issue has been resolved. Like mcaulifn, however, I would like to know what kind of impact this setting change might have on ActiveSync clients. In my current environment, our ActiveSync devices aren't hitting the F5 but at down the road, we will want them to. mcaulifn also raises a good point; if that setting is known to cause issues with OWA, why does it remain in the deployment guide? mcaulifn, depending on your configuration, the use of Nagle's Algorhithm can cause a delay in Outlook connecting; we disabled it here on our client profiles.

This is not going to break anything for ActiveSync. Accept-encoding header only controls whether the client accepts compression and what type of compression. Since LTM is a full proxy, it is typically tasked with compressing content to the client if the client sends Accept-Encoding header(all modern browsers do). However, sometimes CAS servers are also configured to do compression, and that is unnecessary burden on the server, so unchecking Keep Accept-Encoding simply removes that header from the payload before it reaches the server and stops the server from compressing content. Hope it makes sense.