I would hope that the data center engineers built and ran suite of tests to 
find failure points before the network infrastructure was put into production. 
That said, changes are made constantly to the infrastructure and it can become 
very difficult very quickly to know if the failovers are still going to work. 
This is one place where the power and network in a datacenter divulge. The 
power systems may take on additional load over the course of the life of the 
facility, but the transfer switches and generators do not get many changes made 
to them.  Also, network infrastructure tests are not going to be zero impact if 
there is a config problem. Generator tests are much easier. You can start up 
the generator and do a load test. You can also load test the UPS systems as 
well. Then you can initiate your failover. Network tests are not going to be 
zero impact even if there isn't a problem. Let's say you wanted to power fail a 
edge router participating in BGP, it can take 30 seconds for that routers route 
to get withdrawn from the BGP tables of the world. The other problem is network 
failures always seem to come from "unexpected" issues. I always love it when I 
get an outage report from my ISP's or datacenter and they say an "unexpected 
issue" or "unforseen issue" caused the problem.


Dylan
-----Original Message-----
From: Dan Snyder [mailto:[email protected]] 
Sent: Monday, August 24, 2009 8:39 AM
To: Ken Gilmour
Cc: NANOG list
Subject: Re: Data Center testing

We have done power tests before and had no problem.  I guess I am looking for 
someone who does testing of the network equipment outside of just power tests.  
We had an outage due to a configuration mistake that became apparent when a 
switch failed.  It didn't cause a problem however when we did a power test for 
the whole data center.

-Dan


On Mon, Aug 24, 2009 at 9:31 AM, Ken Gilmour <[email protected]> wrote:

> I know Peer1 in vancouver reguarly send out notifications of 
> "non-impacting" generator load testing, like monthly. Also InterXion 
> in Dublin, Ireland have occasionally sent me notification that there 
> was a power outage of less than a minute however their backup 
> successfully took the load.
>
> I only remember one complete outage in Peer1 a few years ago... Never 
> seen any outage in InterXion Dublin.
>
> Also I don't ever remember any power failure at AiNet (Deepak will 
> probably elaborate)
>
> 2009/8/24 Dan Snyder <[email protected]>:
> > Does any one know of any data centers that do failure testing of 
> > their networking equipment regularly? I mean to verify that 
> > everything fails over properly after changes have been made over 
> > time.  Is there any best practice guides for doing this?
> >
> > Thanks,
> > Dan
> >
>


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