mc performance tuning; was: taint mode: insecure dependency in
dormando at rydia.net
Sun Jun 29 21:55:20 UTC 2008
Jeff McCarrell wrote:
> re: contention for memcache
> Well, we don't have a very standard kind of web app.
> The data show that running 8 memcaches is better for us than 1:
No no, I believe you see benefit when doing so :) I'm just not positive
something else isn't going on here :) I've yet to see a single instance
host actually overpower a memcached instance and not have it be some
It might be those multiget's, I guess.
> The graph shows the avg time to process the complete request.
> The X axis shows concurrent streams of requests being sent to apache.
> Each request makes several to small tens of memcache gets, and 1 multi-get.
> My next set of tests will compare 8 vs 16 memcaches and scale up the number
> of concurrent requests.
> re: localhost:12211 vs unix domain sockets
> Um, yes, I can test tcp sockets vs. unix domain sockets if there is a good
> reason to. My belief is that unix domain sockets are the fastest in
> general; is there something specific to memcache that suggests otherwise?
They're actually the same speed on linux these days, or thereabouts. Was
curious to rule it out, is all.
> re: multi-threaded memcache
> I read about multi-threaded mc with interest.
> In general, I'm leery of threading, but I would be willing to look further
> into it with a little encouragement. :-)
> We are running LAMP on linux 2.6 64-bit where the p is perl 5.8.5.
> Is there a consensus view that memcache threading works well on that
Threaded mode is the new default. It works well enough for most of us.
Should be more (memory) efficient for you than multiple independent caches.
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