[consulting] Dedicated/Colocated Servers?

[Mark Shropshire]

I agree. Also, keep in mind that the reason someone may want to have  
the database on a different physical or vps server is because of  
performance.. of course php and mysql on the same machine is arguably  
better performance since sockets can be used and the network doesn't  
have to come into the picture for every query. It really depends on  
where the performance issue lies.

Infrastructure can be complicated in general. No one solution will  
fit all. For example, clusters provide reliability, but if one  
machine in a cluster gets a virus or is otherwise compromised, it is  
the probably that every machine in the cluster will then be  
compromised. There are times that a failover server using an app like  
heartbeat may be better. Just depends. Either way, good reliable  
backups are still needed in case a server has to be rebuilt and  
restored. At work, I have disk to disk to tape for backup. That  
provides our Drupal sites very reliable backup and I like having the  
ability to restore from disk which is very fast.

I like Boris' comment on a reliable SAN w/VPS. That is exactly  
benefit I have received with my vps host. They have a Raid 10 SAN.  
There was an issue last year with the hardware node one of my VPSs  
was running on. They were able to move my entire server to a new  
server node. I had about a minute of downtime when they flipped the  
switch to bring up the new node.

Thanks,
Mark

On Jan 15, 2007, at 11:34 AM, Boris Mann wrote:

> On 1/15/07, Greg Knaddison - GVS <Greg at growingventuresolutions.com>  
> wrote:
>> On 1/15/07, Mark Shropshire <mdshrops at shropnet.com> wrote:
>>> I agree. The beauty of VPSs is that you can bring up various VPSs
>>> each with their own purpose if needed. 1 for web, 1 for db, 1 for
>>> LDAP, 1 for DNS, etc..  Make sure to request that each VPS runs on a
>>> different hardware node so they all don't go down if there is an  
>>> issue.
>>
>> I'm not sure the idea of putting the VPS on separate servers helps
>> improve uptime.  If the chance of a server going down is the same for
>> all servers, then sticking my web VPS on one physical machine and my
>> DB VPS on another physical machine would double the occurrences of
>> downtime in the case that my website is reliant on the DB (which is
>> 99% true for Drupal sites - the 1% being boost or reverse-proxied
>> sites).  Right?
>>
>> Or am I missing something?
>
> It depends is the short answer. For example, we're working on mounting
> the filesystem for Xen VPS from a high-reliability SAN. If the
> physical processing box has issues, the image is stored externally,
> and can be brought back up on another processing machine within
> minutes.
>
> But you are correct in that you have 2 single points of failure in
> terms of services. Smaller machines set up in a clustered config are
> much more reliable...depends on whether you are optimizing for
> performance or reliability.
>
> -- 
> Boris Mann
> Vancouver 778-896-2747
> San Francisco 415-367-3595
> Skype borismann
> http://www.bryght.com
> _______________________________________________
> consulting mailing list
> consulting at drupal.org
> http://lists.drupal.org/mailman/listinfo/consulting