[TriLUG] Memcached and VMware ESX

[John Wheeler]

2 Dell 2950's

-John

On Jul 2, 2009, at 2:49 PM, Andrew Ball wrote:

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