if item expired it will not be counted as evicted. So you need to look into "stats items" (https://dev.mysql.com/doc/mysql-ha-scalability/en/ha-memcached-stats-items.html) and look for evictions. If you have evictions this means that you do not have enough memory (or memory was allocated in other slabs: memcached does not free slabs by default, so if you for example allocated all memory for 4K slab and do not use it anymore, e.g. everything is expired in 4K slab - you wont be able to allocate memory for 1MB slab)
On Wednesday, December 9, 2015 at 11:46:06 AM UTC-8, Bill Moseley wrote: > > We store some items with a 60 minute expires, yet are seeing a few log > entires in our app that indicate that they are missing from Memcached much > sooner (like 10 to 15 minutes). > > We are also running a quite old version of Memcached: 1.4.4. > > Are there any stats that would tell me if items are being evicted before > their expires time? > > What else should I look at to understand why they might be removed from > the cache? > > Do evictions only happen when a new page cannot be created? That is > limit_maxbytes - bytes is not enough for a new page for the given slab > size? Is expires time considered with LRU? > > > Thanks, > > > At the high level I'm seeing this: > > About 100 evictions/second, 1K sets/sec and 200K reads/sec. > > > STAT limit_maxbytes 8,589,934,592 > STAT bytes 7,438,136,137 > STAT curr_items 51,229,586 > STAT total_items 878,415,745 > STAT evictions 267,995,993 > > > > -- > Bill Moseley > mos...@hank.org <javascript:> > > -- --- 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/d/optout.
