in reply to Re^4: PerlMonks Caching
in thread PerlMonks Caching

I don't understand the problem. Do you think somehow that a memcached client is not robust enough to handle something like that? A database server also can have problems. The clients usually handle it. memcached server and clients are really ready for production. xing uses memcached a lot. facebook uses it afaik. why do you think there could be a connection problem? did somebody tell you about problems?
I was told that if one of the memcached nodes in a cluster "vanishes" - for whatever reason - the client realizes it and reorganizes its distribution of keys then. it can't get worse than now, I'd say.

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Re^6: PerlMonks Caching
by Corion (Patriarch) on Apr 21, 2010 at 10:13 UTC

    I've read many articles on memcached, but haven't used it myself. It claims to do failover across multiple memcached servers, but I haven't seen it in action myself, and also what it does when the last server becomes unreachable. I don't know how stable it is, and what the requirements (and administrative overhead) of its users are, and also what its failure modes are.

    At PM, we have MySQL behave erratically and grind to a halt from time to time, needing a restart. If memcached also exhibits that ("Just Restart It"), that would introduce yet another slowness problem. And such, I'm wary of enthusiastically following what others claim works for them when I haven't played around with it myself. And I'm looking towards its failure modes because we experience failure modes with MySQL.

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      I'm wary of enthusiastically following what others claim works for them when I haven't played around with it myself.

      FWIW: Others seem to be convinced by it.

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        Sure - and I'm also convinced that it's worth looking into. I'm looking to implement it for a small test case (federation of RSS feeds). But as I haven't used it, or the Perl libraries, I'm not sure that memcached is The Silver Bullet.

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      And such, I'm wary of enthusiastically following what others claim works for them when I haven't played around with it myself.
      Well, I'm sorry. I'm just trying to help. If you're the boss and have to approve everything that runs on the server by loadtesting it yourself, then I can only recommend it and that's it.
      The problems you have with mysql I don't have on our server. 2 mysql servers running and replicating for months now without needing to restart. (update: and, at work, also several servers with *lots* of inserts are just running and running and running)
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        Your help and support is appreciated! I think my replies come across as that I don't want to implement memcached caching. I do want to give it a try.

        But to give it a try, I have to install, secure and set up memcached, and look for a spot where I can use it easily within PM, so it's just not instantaneous.

[reply]

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