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<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>At peak times we see about 35-40% utilization (that’s across all 4 CPUs.) But as you say, that number will vary dramatically depending on how you use it. The biggest single user of CPU time isn’t actually memcached per se; it’s interrupt handling for all the incoming packets.<BR>
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-Steve<BR>
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On 5/3/07 11:41 AM, "Jerry Maldonado" <jerry.maldonado@apollogrp.edu> wrote:<BR>
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</SPAN></FONT><BLOCKQUOTE><SPAN STYLE='font-size:12.0px'><FONT COLOR="#0000FF"><FONT FACE="Arial">With the configuration you noted below, what is your CPU utilization. We are implementing memcached in our environment and I am trying to get a feel for what we will need for production. I realize that it all depends on how we are using it, but I am interested to see what it is based on your configuration.<BR>
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</FONT><FONT COLOR="#0000FF"><FONT FACE="Arial">Thanks,<BR>
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</FONT><FONT COLOR="#0000FF"><FONT FACE="Arial">Jerry<BR>
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</FONT><FONT FACE="Tahoma">-----Original Message-----<BR>
<B>From:</B> memcached-bounces@lists.danga.com [<a href="mailto:memcached-bounces@lists.danga.com]">mailto:memcached-bounces@lists.danga.com]</a><B>On Behalf Of </B>Steve Grimm<BR>
<B>Sent:</B> Thursday, May 03, 2007 11:33 AM<BR>
<B>To:</B> Sam Lavery; memcached@lists.danga.com<BR>
<B>Subject:</B> Re: Largest production memcached install?<BR>
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</FONT></SPAN></BLOCKQUOTE><SPAN STYLE='font-size:12.0px'><FONT FACE="Verdana, Helvetica, Arial">No clue if we’re the largest installation, but Facebook has roughly 200 dedicated memcached servers in its production environment, plus a small number of others for development and so on. A few of those 200 are hot spares. They are all 16GB 4-core AMD64 boxes, just because that’s where the price/performance sweet spot is for us right now (though it looks like 32GB boxes are getting more economical lately, so I suspect we’ll roll out some of those this year.)<BR>
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We have a home-built management and monitoring system that keeps track of all our servers, both memcached and other custom backend stuff. Some of our other backend services are written memcached-style with fully interchangeable instances; for such services, the monitoring system knows how to take a hot spare and swap it into place when a live server has a failure. When one of our memcached servers dies, a replacement is always up and running in under a minute.<BR>
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All our services use a unified database-backed configuration scheme which has a Web front-end we use for manual operations like adding servers to handle increased load. Unfortunately that management and configuration system is highly tailored to our particular environment, but I expect you could accomplish something similar on the monitoring side using Nagios or another such app.<BR>
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All that said, I agree with the earlier comment on this list: start small to get some experience running memcached in a production environment. It’s easy enough to expand later once you have appropriate expertise and code in place to make things run smoothly.<BR>
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-Steve<BR>
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On 5/3/07 8:06 AM, "Sam Lavery" <sam.lavery@gmail.com> wrote:<BR>
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</FONT></SPAN><BLOCKQUOTE><SPAN STYLE='font-size:12.0px'><FONT FACE="Verdana, Helvetica, Arial">Does anyone know what the largest installation of memcached currently is? I'm considering putting it on 100+ machines(solaris/mod_perl), and would love to hear any tips people have for managing a group of that size(and larger). Additionally, are there any particular patches I should try out for this specific platform? <BR>
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Thanks in advance,<BR>
Sam<BR>
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