[DCN-TechOps] Base Specs for App Server

[Steve McMahon]

Thanks for the suggestions!

We're already fronting Zope with Apache, and use it to cache what can be 
cached. That helps with public pages, but still leaves us hurting on 
items that can't be cached -- like management interface pages and 
election result pages. (Also, I'm not seeing as much benefit from 
caching on this machine as I've seen on others. Something's adding some 
latency to the apache-cache served files. They're still faster than Zope 
pages, just not as much as you'd expect.)

The machine we're currently using as our main Zope server has four 
166mHz processors. I'm pretty sure that Zope/Python's threading isn't 
making good use of the multiple processors (a known problem with 
Solaris), so this is acting like a slow, single-processor machine as far 
as Zope's concerned. One possible improvement might come from using ZEO 
and binding the Zope client and the ZODB database to different 
processors. But I think that would just be a holding action.

Another consideration is that we'd like to be running some Plone sites. 
I don't know if you've worked with Plone, but its ZPT pages typically 
take about ten times as long to serve as DTML pages. (That also means 
that they benefit even more from caching.)

I hadn't thought about Opteron options, so thanks for pointing us in 
that direction. The memory use benchmarks make it look like it might be 
a great Zope platform.

Steve

Bill Broadley wrote:

> On Fri, Mar 12, 2004 at 09:18:10AM -0800, Steve McMahon wrote:
> 
>>Great meeting last night! Here are my baseline specs for the app server.
> 
> 
> ACK, I had the best of intensions for attending this one.  I've quite
> a bit of experience with Zope at Math and CSE.
> 
> 
>>Goal: platform for cpu/ram intensive apps like Zope.
> 
> 
> I'd start with making sure that apache or similar is configured to act as
> a cache for zope, it makes all the difference in the world performance
> wise, and nicely integrates into Zope (i.e. timeout values under the
> zope properties panel).  I've seen performance improvements over
> a factor of 10.
> 
> 
>>Processor: Performance roughly comparable to (or better than) 2GHz Intel
>>
>>RAM: 1 GB DDR ECC
> 
> 
> I'd strongly recommend getting an Opteron from Sun, IBM, HP or one
> of the smaller vendors.  Especially on dynamic content and database
> related work.
> 
> HP's dual opteron page has a web benchmark where a single opteron out
> performs a dual P4.  Ars technia, among others have shown the opteron
> to have significant advantages for this kind of thing.  The opteron is
> rather unique in that often the dual cpu actually manages double
> the throughput of a single cpu machine.
> 
> I can dig up URLs if needed.
> 
> 
>>Storage: ~200 GB -- possibly configured as two drives in RAID1; At least 
>>7,200 RPM, (10,000 would be nice, but may be too expensive); Ultra DMA 
>>or SCSI
> 
> 
> In most cases I've seen performance for this kind of thing scales
> much closer to the number of heads and hardly at all with RPM.  I'd
> recommend 2-4 160 GB drives for $100 each or so.  Preferably SATA.
> 
> Ideally you have enough ram to minimize the disk intensive nature
> of your workload.
> 
> 
>>Tape Backup: I hope someone who knows these gadgets better can spec this 
>>part. In any case, compatible with what's otherwise in use by DCN.
> 
> 
> I can't comment without knowing what is in use by DCN, but am reasonably
> familiar with the tape technologies available.  With more info I could
> help make a suggestion.
> 
> The AMD has other benefits, it's more secure with hardware to help avoid
> buffer overflows, it can directly address > 4GB ram, and is rather
> inexpensive.  Appro sells duals with 4GB ram starting at $2,100, Sun
> starts at $2,795, and HP starts at $1600.  Not sure if this fits the
> budget or not.
> 

-- 
______________________________________________________

Steve McMahon
steve at dcn.org