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RTC Application Move from a Physical server to a VM


Tom Choquette (335) | asked Jul 17 '14, 9:02 a.m.
All,
We have our current RTC application, including RM and QM installed on a physical server configured with CPUs: 8  2.93GHz MEM: 48GB.   This server also houses 5 other applications as well.  We were thinking about moving the application to a VM configured with CPUa: 4   2.40GHz MEM: 15GB and the only other applications that will be running on this VM is RRDI, Cognos and Websphere 8.5.0.2 all of which are 64 bit apps. 

From what I was told, as soon as we move the app to a VM, we would experience a 20% loss in performance.  Is this a correct assumption and, if it's noted, what would be the possible cause of this performance loss.

If this is a correct statement, are there any OS or Application adjustments that can be made to adjust for this?

Thanks
Tom C.

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sam detweiler (12.5k6189201) | answered Jul 17 '14, 9:26 a.m.
well, virtual is not 100% of physical. and you are going to a 20% slower processor
2.40/2.93 = .81 (+ the VM difference)
and 1/2 the processors so if there was waiting before, you will wait more or thread switch more.. so a small increase in overhead.
and I would be wary of putting reporting on the same server as the RTC app.. reporting is CPU heavy.
I assume the DB is on another machine.

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Tom Choquette commented Jul 17 '14, 9:41 a.m.

Sam,

Thanks for responding so quickly.  Yes, the DB is on another server.  We have the RTC, 4.0.6, JVM set to 5 GB only so that leaves 10 GB available.  Will RRDI consume more than 10 GB?  If so then we have other issues.:-)  Our RTC instance currently runs on Tomcat and another option was to configure a 2nd instance and load balance the traffic but from what I was told, there is no reliable solution available at this time, not even if we move RTC to Websphere.  I hear that future versions of RTC will have this available.
Any recommended config changes that other may have done to correct some of the performance hit either on the app side or VM?

Thanks again,
Tom C. 


sam detweiler commented Jul 17 '14, 9:54 a.m.

RRDI/Cognos, I wasn't worried about memory.. worried about processor availability for RTC app.  we had a shared VM machine and constantly had perf problems cause the other VM's had higher proprity, and other apps spiked performance when we needed 100% for RTC.   so sharing is not a favored approach for me.

I can't help on any specific config changes to mitigate the impacts as they are really physical in nature.. slower processor and system sharing on a virtual environment.  (you can't go slower and make it up in volume!)

yes, sadly RTC does not support the std application model where u can spin up another engine and load balance work over one database.. Each new instance is a separate unique database.  I haven't seen any real plan to change the design (it would solve and incredible number of operational, deployment and scalability problems)

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