I can’t tell you how pleased I was to see VMware _finally_ publish some data on a more realistic XenApp scenario than they have previously. Back in the days they used to push a single vCPU for Terminal Servers argument, which as any Citrix guy will know is sub-optimal in more than a few aspects (mostly relating to the relationship of the TS console session and logons to CPU0).
Now I’ll be the first to admit that any kind of test and resulting statistical analysis can be very subjective, but I’ll tell you what I think is the most important point to take from this latest study from VMware – the performance isn’t that different. Sure ESX came out on top, but not by much (I’m sure Citrix will come out with some kind of data that shows the contrary before too long, and that’s fine). And why is that important? Because I am sick and tired of the marketing bullshit from Citrix and subsequent throwaway one-liners that propagate through the intertubes and into the minds of Administrators in the enterprise, regarding XenServer being “optimised for XenApp“. I have _never_ seen any further details on what this actually means.
Well I’m throwing down the gauntlet on this one. I’m opening up the comments on this post, in the hope that Simon Crosby, Ian Pratt, or anyone else I highly respect on a technical level who works for Citrix to tell us all what the fuck these XenApp specific optimisations in XenServer actually are and why the same configuration could not be implemented with tweaks to ESX (not that they’re even necessary, going by the VMware post). I’ll even take a reply from hype-master Roger Klorese. If it is some kind of secret, I have no problem with that – just tell us so (and I’ll continue to call it complete BS). If it’s something that can only be disclosed under NDA, then tell us that too because I guarantee you that 90% of the people who read this blog regularly are working for large enterprises who have NDA’s in place with Citrix, so we can follow that avenue if necessary (and of course honour the NDA – I’m not stupid enough to lose my job for the sake of this blog). Cut the bullshit Citrix – we just want to know.
UPDATE As numerous commenters have pointed out, I completely neglected to mention the excellent work of Project VRC. But again, in line with my original comment, the differences in hypervisors are so minor that it really doesn’t matter – as Duncan said, the main thing is that Citrix workloads are finally viable targets for virtualisation, because the difference to physical is also insignificant when you consider all the benefits of virtualisation.
As for Simon Crosby’s retort, I won’t bother picking through it. Citrix are easily as guilty as anyone when it comes to spreading one sided “studies” under the guise of science, and their best buddies at Microsoft are the kings of the hill in that arena. Here’s a tip for you Simon – Microsoft are also the kings of “embrace, extend, extinguish“, remember? We all know what’s gonna happen when they enter the connection broker market.
BUT I will say this much in credit to Simon – he hit the nail on the head with his comments regarding VMware’s draconian “thou shalt not publish benchmarks” stance. This has been a bugbear of mine for a long time, and I’ve said as much to fairly senior people at VMware. A change in that would be most welcome indeed.
Also as a few of the anonymous commenters pointed out, Citrix offered this explanation 6 months ago as to what the ‘secret XenApp optimisation sauce’ is. Which I can only assume is now completely null and void with the widespread availability of RVI / EPT. Oh well, was fun while it lasted I guess.