I can only assume so. I don't directly manage our Citrix environment, I'm just offering assistance wherever possible. I know we've had Citrix Consulting onsite to perform a specific health check, we've had our networking team continually monitoring everything possible (we have a CCIE on-staff, if that means anything anymore), and our own Citrix admin team has been digging into all areas of performance analysis, using the usual tools as well as specific monitoring solutions we have such as EGManager.
The initial response from the consultants is to plan migration to XenApp 6 as soon as possible. We're also a little behind as we're running CPS 4.5 hotfix rollup pack 2, so it's suggested we upgrade to rollup pack 6(?). They confirmed the behavior we're seeing is due to the use of session reliability (applictions hanging rather than the sessions being disconnected), so they've indicated we need to dig deeper into our network investigation as the problems seem to indicate a loss of communication. However, the recent article I linked in my original e-mail seems to indicate that the problems we're seeing can often be incorrectly attributed to network problems. So far we've been unable to identify any network communication issues. The problems effect users on our local LAN as well as branch offices over WAN connections. We have one of our managers using applications published off of a specific server so that we can focus our troubleshooting efforts. We have batch scripts published from this server that runs a debugging tool given to us by a Microsoft developer. There's 3 scripts configured for Outlook, Word, Excel. If the manager experiences a significant application hang, he executes the respective script which debugs the corresponding process for his session. Analysis, by Microsoft, of several of those outputs has turned up nothing. However, our Network Engineer has a sniffer setup to monitor all communication from the manager's PC to the Citrix server. During the perceived application hangs, our network engineer has identified that both the NIC on the client PC and on the Citrix server appear to be "hanging on to packets" for up to several hundred seconds before releasing them. This was just recently identified so I don't think we've dug into possible causes of that behavior. - Sean On Wed, Aug 4, 2010 at 11:51 AM, Webster <[email protected]> wrote: > Are you monitoring the standard TS/RDS/Ctx perfmon counters? > > > > > > Webster > > > > *From:* Sean Martin [mailto:[email protected]] > *Subject:* Re: Tweaking Performance - Citrix Servers > > > > Thanks for the response. > > > > Yeah, we've noticed a big difference between our older servers without > caching and newer ones with it. Unfortunately we can't dedicate the time to > our hardware refresh project that would eliminate those older servers. We're > in the process of redistributing the newer hardware to the application silo > running the Office suite, since that's where most of our performance > complaints stem from. > > > > Even with caching enabled, we still receive complaints of application hangs > when users are connected to one of the newer servers. We've spent the last > several months investigating the issue and trying to resolve it for good. > We've made progress, we just haven't eliminated the occurrences. > > > > If you're referring to the lack of fault tolerance with a RAID0 setup, then > we understand the cons very well. We have enough servers in our farm that we > can lose a handful of servers due to disk failure and still support > production (albeit performance may suffer a little more). We have a fairly > decent stock of spare parts as well. > > > > - Sean > > On Wed, Aug 4, 2010 at 10:40 AM, Webster <[email protected]> wrote: > > I have seen issues with the blade RAID Controllers NOT having a battery > backup cache controller. That will seriously impact performance. > > > > I don’t think RAID0 will negatively affect the page file. Just remember > the caveats of using RAID0. > > > > Before you go making changes, create a baseline to measure against. > > > > > > Webster > > Citrix Technology Professional > > > > *From:* Sean Martin [mailto:[email protected]] > *Subject:* Tweaking Performance - Citrix Servers > > We use Blade servers in our Presentation Server 4.5 environment > (approximatley 100 server split between 8 application silos). The hardware > ranges from Dell PowerEdge 1955s to newer Dell M610s. We've been toying with > ways to increase performance of the servers and recognize that disk > performance on our Blades is usually the bottleneck. In our standard > configuration, the two drives (1955s = 73GB/10k, M610s = 146GB/15K) are > mirrored. We've configured a couple of servers with no RAID (two independant > disks) and tried balancing resources across the two (page file, temp > directories, spooler directory, etc). While this did yield some positive > results, it wasn't that noticeable in the grand scheme of things. > > I just read the following article from Citrix, apparently published on > 7/21/2010. The issues referred to are currently what plague our environment > the most. One of the recommendations is to try a RAID 0 configuration in > Blade systems with only two drives. We've historically written this off as a > solution because of the recommendation of not striping a page file. Do you > think the potential fragmentation issues would be considered an acceptable > risk when compared to the potential disk performance improvements? We do > have Diskkeeper installed on all of our servers which is scheduled to run > during the evening hours. I do believe it addresses page file fragmentation > but it has been awhile since I've looked into the capabilities of the > product. > > > > I should note that our M610s with 256MB cache (caching enabled) and RAID1 > do seem to perform much better than our older servers. > > > > http://support.citrix.com/article/CTX125882 > > > > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
