Changed App Server from single to dual processor virtual machine; Now queries take twice as long! Why?

[Deborah_Hack]

OnBase 13 SP2

We have our Application Server on a virtual server. In an attempt to improve performance, we reconfigured the virtual machine from a single processor to dual processor. Instead of improving performance, the opposite has occured. For example, queries now take TWICE as long to return the hit list.

While I'm waiting for help from my support, can anyone give me any ideas of why performance got worse? Any ideas of what I should check?

It's been a bad day.........

Thanks for any suggestions.

-Deborah

[Matt_OConnell]

Hello Deborah

Thank you for your post.

In regards to virtual machines, VMs have to wait for cores to be available in order to execute instructions.

For example: A 1vCPU VM will be able to execute an instruction as soon as a single core is available. However a 4vCPU VM has to wait until 4 cores are available in order to execute an instruction. So depending on the load of the host, this might degrade performance on the VM.

This speaks from my experience with our internal VMware ESX environment. Hyper-V or Oracle VirtualBox will be a little different, but the concept tends to be the same.

Thank you

Matthew O’Connell
QA Infrastructure Administrator
Hyland, creator of OnBase ®
Office: (440) 788-5509
Mobile: (216) 318-6547

[Laurie_Mordick]

How does Hyper differ?

[Matt_OConnell]

Hello Laurie

Both Hyper-V and VMware have similar methods for cpu contention (although there has not been that much written comparing the two). 

There is a difference in how one can manually manage cpu allocation in VMware and Hyper-V.  This would probably fix the issue on the VM itself (for Deborah's issue).  Depending on the load of the host it might affect other virtual machine performance. It is always difficult to find the happy medium in VM performance for either Hyper-V or VMware. 

On our internal test environment, we tend to keep application server VMs at a single core and increase the RAM if performance degrades.  However, our host load tends to run high which does not allow us to have as many resources to allocate.

Thanks

Matthew O’Connell

QA Infrastructure Administrator

Hyland, creator of OnBase ®

Office: (440) 788-5509

Mobile: (216) 318-6547

[Deborah_Hack]

Matt-

THANK YOU for the information regarding performance on virtual machines. You brightened my day!

-Deborah