Hello! On Fri, Oct 22, 2010 at 02:51:05PM -0700, amix wrote:
> Have done some more debugging and here is what I have found. > > The general main differences for these two servers seems to be: > 'curr_items': '132819', (memcached 1.4.5) > 'curr_items': '3907837', (memcached 1.2.2) > > Total items seem to be very similar, i.e. > 'total_items': '62899221', (memcached 1.4.5) > 'total_items': '68416527', (memcached 1.2.2) > > Testing memcached 1.2.2 and memcached 1.4.5 and filling it up with > sample data it seems like memcached 1.4.5 is much better at using > memory that has been allocated by expired items. Is this correct? > > If so, it would mean that our cache is way underutilized in general > and that 1.4.5 is much better at managing memory (i.e. it won't > allocate memory if it does not need to). > > Could someone that's familiar with memcached internals please confirm > this. Yes. Re-use of expired items before allocating new items was done by Trond Norbye[1][2] (in 1.4.0+). Note that "reclaimed" stats shows how many times memcached re-used expired items. [1] http://code.google.com/p/memcached/issues/detail?id=14 [2] http://github.com/memcached/memcached/commit/d3807d06f0693b0435545d35462de2829a61a7d1 Maxim Dounin
