[TriLUG] Memcached and VMware ESX

[Andrew Ball]

It probably won't slow things down a whole lot.  We use Xen virtual machines
at work running on Debian for just about everything and are very happy with
it.  I think memcached is particularly easy to do well for either hypervisor
as it's mostly just RAM access and network traffic.

What sort of hardware are you using?

Peace,
Andrew


On Thu, Jul 2, 2009 at 12:04 PM, John Wheeler
<jwheeler at etherealfringe.com>wrote:

> Hey guys,
>
> I'm re-factoring some caching code for our web application and working with
> IT to implement our new dedicated memcached servers.
> We have two machines with 32Gb a piece.
>
> The nature of our application is that multiple client communities receive
> the same kind of service but with completely different data sets and search
> vectors.
> We want to balance the load by distributing the heavy lifting of some
> search vectors to memcahce.
>
> We can either install thin OS's on each machine and have two memcached
> servers, or we can lose 4Gb off the top on each box (to the VMware
> hypervisor) and create virtual memcached servers.
> We run WMware ESX.
>
> The key is that this has to be as fast as possible.
> I am looking for opinions on whether or not running inside the hypervisor
> will slow the speed of direct memory access by the memcached processes
> living inside the virtual machines by any significant amount relative to
> normal memcached response times.
> The benefit we get by virtualizing is the ability to provision memcached
> server pools for individual client implementations, keeping heavier
> application deployments bucketed into their own pools so as not to overwhelm
> and push out the smaller, less accessed implementation's cache entries.
>
> I am not really concerned about losing the 4Gb to the hypervisor, but
> should running in a virtualized environment like this slow down our
> application requests to the memcached server?
>
>
> John Wheeler
> Web Applications Developer
> jwheeler at etherealfringe.com
> 336-255-8004
>
> --
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>



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=======================
Andrew D. Ball
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deus caritas est
http://www.ibiblio.org/adball/blog/
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