there was supposed to be a rebalancing functionality but i am not sure if it went into stable already? lately i was busy doing other things.
can anyone confirm what is the status of reclaiming slabs please? I am also interested is it available. thanks art On 30 November 2010 14:49, Kaiwang Chen <[email protected]> wrote: > Is there any way to shrink slab class so that space allocated at peak > time can be reused for other slab classes later? > > Thanks, > kc > > 2010/11/5 Artur Ejsmont <[email protected]>: >> Mikael can be right. >> >> Each slab is 1mb and its designated to hold items of particualr size. >> So if you had 5000 items over 500KB inserted into the cache at some >> time ( at the beginning ) they would consume 5GB (they would take 1MB >> each even if they were 501KB). >> >> So after some time caching patterns change and you dont insert big >> items any more. This 5GB is wasted if you are not using such big items >> any more. So distribution changes and big items are not needed any >> more but more smaller items cant fit into the cache as memcached cant >> put small items into slabs designated for big items. >> >> Sorry if my explanation is not super good :) >> >> checkout this tool out though >> http://artur.ejsmont.org/blog/content/first-version-of-memcache-stats-script-based-on-memcachephp >> >> i took a open source stats scripts and added detailed view of slabs. >> It should tell you how many slabs you have allocated per size and how >> many items are there. I guess this should give you good idea what is >> really happening. >> >> :- ) >> >> art >> >> >> >> On 5 November 2010 05:59, vishnu <[email protected]> wrote: >>> What is slab distribution? >>> >>> How can i resolve this issue? >>> >>> Thanks. >>> >>> On Thu, Nov 4, 2010 at 10:40 PM, dormando <[email protected]> wrote: >>>> >>>> reclaims are good, evictions are bad >>>> >>>> On Thu, 4 Nov 2010, Kate Wang wrote: >>>> >>>> > We are experiencing high reclaims instead of evictions. Could slab >>>> > distribution shift cause that as well? >>>> > >>>> > If the slab distribution shifted could cause high eviction rate, what's >>>> > the best way to fix it or avoid it? >>>> > >>>> > Thanks! >>>> > >>>> > On Thu, Nov 4, 2010 at 5:52 PM, Mikael Fridh <[email protected]> wrote: >>>> > On Nov 4, 6:32 pm, rahul_kcle <[email protected]> wrote: >>>> > > >>>> > > From last 2 weeks i am seeing evictions happening on our >>>> > memcached >>>> > > boxes even though there is lot of memory left . Here are the >>>> > stats >>>> > > from memcached >>>> > > >>>> > > STAT bytes_read 434627188758 >>>> > > STAT bytes_written 357821569260 >>>> > > STAT limit_maxbytes 23622320128 >>>> > > STAT accepting_conns 1 >>>> > > STAT listen_disabled_num 0 >>>> > > STAT threads 5 >>>> > > STAT conn_yields 0 >>>> > > STAT bytes 14573115225 >>>> > > STAT curr_items 1853350 >>>> > > STAT total_items 66439158 >>>> > > STAT evictions 7000591 >>>> > > >>>> > > Bytes is much lessser than limit_maxbytes. >>>> > >>>> > See stats slabs, possibly your slab distribution profile have shifted >>>> > over time. >>>> > >>>> > Mikael >>>> > >>>> > >>>> > >>>> > >>> >> >> >> >> -- >> Visit me at: >> http://artur.ejsmont.org/blog/ >> > -- Visit me at: http://artur.ejsmont.org/blog/
