Lazy Garbage Collection Question

Adam Hiatt adam.hiatt at
Sun Apr 30 00:32:24 UTC 2006

I've noticed a couple threads in the mailing list archives with  
questions concerning the lazy garbage collection for expiring  
entries. One user attempted to write a 'reaper' agent that  
specifically cleaned up their cache. Now this clearly should not be  
necessary, but from what I read it appears that they felt that it was  
critical because the memcached processes kept using memory until it  
had to swap to disk. I wasn't able to determine this from the  
threads, so, is the consensus that these deployments of memcached are  
configured to use more memory than the system will provide to it and  
that when the configured level is approached the OS is forced to swap  
to disk? Or, is there some actual problem that prevents deallocation  
and causes memory leaks force these swaps. I am concerned because I  
am looking into using memcached in a production environment and on at  
least one of the threads I referenced, I noticed that the  
administrators had to restart the boxes every couple of days or so.

Adam Hiatt (adam.hiatt at

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