On Thursday, February 14, 2013 1:31:45 PM UTC+4, Dormando wrote: > > > Hello All !))I have a some problem. > > We have 3 memcached nodes cluster (memcached version: 1.4.5). > > Average loading on every node is about 300-350 req/s. > > We are interacting with memcached throw JAVA-API (net.spy.memcached) > > But sometimes (very rarely) we gets error lines in our application log, > as folowing: > > > > 01:00:59 ERROR Error: �Out of memory > > 01:30:01 ERROR Error: �Out of memory > > 03:30:25 ERROR Error: �Out of memory > > 11:11:16 ERROR Error: �Out of memory > > > > > > I can't found any dependencies between these errors and software > environment.� > > And anything: > > I found "outofmemory" errors on some slabs (stats slabs and stats items > requests) as folowing: > > > > server 1: > > > > ........ > > STAT items:39:number 1 > > STAT items:39:age 27457197 > > STAT items:39:evicted 3720 > > STAT items:39:evicted_nonzero 3 > > STAT items:39:evicted_time 10 > > STAT items:39:outofmemory 41 > > STAT items:39:tailrepairs 0 > > STAT items:39:reclaimed 0 > > .......... > > > > stats slabs > > ... > > STAT 39:chunk_size 493552 > > STAT 39:chunks_per_page 2 > > STAT 39:total_pages 1 > > STAT 39:total_chunks 2 > > STAT 39:used_chunks 1 > > STAT 39:free_chunks 1 > > STAT 39:free_chunks_end 0 > > STAT 39:mem_requested 415638 > > STAT 39:get_hits 562215 > > STAT 39:cmd_set 568308 > > STAT 39:delete_hits 0 > > STAT 39:incr_hits 0 > > STAT 39:decr_hits 0 > > STAT 39:cas_hits 0 > > STAT 39:cas_badval 0 > > .... > > STAT active_slabs 42 > > STAT total_malloced 2151880632 > > You should upgrade to the latest version. It might mitigate this a bit > better. > > The problem is most likely that this is a very high slab class. You cans > ee it's big enough that it can only fit two items per page. It only has > one page assigned to the slab class. So there can be only *two* items of > that size stored in your memcached instance. > > Memcached can only store a new item if it has free memory to work with, or > if it can evict a previous item. However, if you're in the process of > fetching or storing an item, the item might be locked. If that happens it > simply says "out of memory". > > You can cause this pretty easily by uploading 3 items in parallel. The > first two will work but the third won't be able to get memory. > > New versions work a bit better, or you can enable slab rebalancing to > allow more memory to be put into the higher slab class when necessary. > > Sorry. It's a bit of an obscure tradeoff. :/ > > -Dormando
Thank you very much ))) As I understand this problem takes place always and there are a few customizations as follow: - increase memory - slab rebalancing Is it true ? -- --- You received this message because you are subscribed to the Google Groups "memcached" group. To unsubscribe from this group and stop receiving emails from it, send an email to memcached+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
