Thanks to all for the suggestions. I didn’t have the idea that memcache uses the clean-up algorithm to clean the items from the cache.
Any way we are planning to store some historic data in the cache for faster access. I agree, we have to plan for the no of instances required and start them based on the data type that we want to store. I know that using the memcache status binary (memstat) we can see the bytes written and limit of max bytes. To test this condition I executed one small program which will keep on adding the items to memcache. Deliberately I started memcache server to assign small amount of memory (./memcached -d -m 1 -l localhost -p 11211). The server allocate only 1048576 bytes of memory. But I found that the bytes_written it not going above 910610 and it is deleting the items from the cache. So I can’t know what is the actual limit where I have to stop. Appreciate any suggestions on this regard. Thanks in advance. Vipin Kalra wrote: > I'll second with the opinion that other people have posted and will not > recommend to add Memcache on the fly. Rather best practice would be forecast > your capacity and plan accordingly for the number of Memcached server which > will provide better scalability. > > To answer to your original question of how to check if memcahced is full is > by checking memcahed status and compare "bytes" with "limit_maxbytes". Pls > note that doing it this way can have performance implications depending on > how often you write into memcache. > > Displaying the cache stats: > pid: 17476 > uptime: 2950218 > time: 1225921019 > version: 1.2.5 > pointer_size: 32 > rusage_user: 0.185971 > rusage_system: 5.735128 > curr_items: 1321 > total_items: 2964 > bytes: 29910319 > curr_connections: 6 > total_connections: 59 > connection_structures: 20 > cmd_get: 3487 > cmd_set: 2964 > get_hits: 2535 > get_misses: 952 > evictions: 0 > bytes_read: 33846167 > bytes_written: 30810647 > limit_maxbytes: 1073741824 > threads: 1 > > > On Wed, Nov 19, 2008 at 7:39 AM, Jose Celestino <[EMAIL PROTECTED]> wrote: > > > > > Words by Jitendra [Wed, Nov 19, 2008 at 01:42:28AM -0800]: > > > > > > Hi, > > > We are planning to implement memcached as part of our project.As the > > > data is huge, we are expecting it will go beyond the size of cache. So > > > how can we know that the cache is full, hence we can start another > > > instance of memcache. > > > > Look for the number of evictions growing when you to stats. > > Evicions happening means memcached is removing active objects from cache > > to make space for new ones. > > > > -- > > Jose Celestino | http://japc.uncovering.org/files/japc-pgpkey.asc > > ---------------------------------------------------------------- > > "One man's theology is another man's belly laugh." -- Robert A. Heinlein > >
