Hi,The 2.2.x branch had the same performance improvement but it wasn't released until a few minutes ago :) Try the 2.2.5 release, should give you better performance when using the consistent hashing strategy.
Available at http://pecl.php.net/package/memcache //Mikael Pavel Aleksandrov wrote:
Yes, I new about the new version which claims to have higher performance for the consistent method, but it's still in beta, so we don't want to experiment with production servers. On 27 Фев, 18:05, Marc Bollinger <[email protected]> wrote:We definitely saw this exact same behavior with the PHP PECL module, using consistent hashing. Weirdly enough, I was just digging around before responding, and version 3.0.4 was released a few days ago with the changelog statement: "Improved performance of consistent hash strategy." You might check that out if you're using a version more than a week old, but it sounds like you've decided against consistent hashing. We initially thought it might be a good idea because we're running memcached instances on EC2, but realized even there, the servers are static enough that having additional overhead for each read isn't worth it. - Marc 2009/2/27 Pavel Aleksandrov <[email protected]>I used "naive" for the standard method, because it's described as such in many places where they talk about this algorithms. As I said in the previous message, we don't expect the instances to go much up or down, so using the standard hashing may be OK for what we need. My question was about the overhead - apparently the module recalculates each time where everything should go and this involves a lot of hashing for each server and that translates in CPU load on the web nodes. On 27 Фев, 17:08, Brian Moon <[email protected]> wrote:On 2/27/09 9:00 AM, Pavel Aleksandrov wrote:Never mind the PHP, it's a topic I don't want to discuss :) About the changes - the only change that made this impact was changing the hash distribution method. We are currently using the new memcache instances, but with the standard, naive method and there are no negative effects on the load of the web nodes. The moment we switch to the consistent method the load jumps.Well, I don't use the consistent hashing. I guess I am naive. I also have not heard of this problem before however. -- Brian.
signature.asc
Description: OpenPGP digital signature
