Hi I have a couple other ideas I'll share in case anyone likes them...
1.) Let the application decide when an object is "too stale." Currently memcached is setup so an expired element is never available, even though it's still in memory. Perhaps another way memcached could work is to report pack, with the data, the age of the data. Then the app can decide if that is too old or not, based on it's needs, and refresh as necessary. 2.) Rather than having a dog pile, you could set a magic "I'm getting that" which is written to the cache on a miss. (best if it's even part of the original get request actually) Other processes, rather than jumping to the database just wait in a loop with some random timeouts calling memcached repeatedly until the data is available. Now, for the big question I've been sitting on for months... Has anyone worked out a system using memcached that guarantee's memcached has the most recent data? Essentially, tying memcached to the database so memcached is never allowed to contain any stale data? I've looked at some soutions involving a timestamp with every record, a revision code, database row locking, etc. I think I've determined that it can be made to work work with the data itself, by disabiling caching when multiple writes are being processed, however I was hoping to find out if anyone's actually made it work. >From what I understand, a system like this can only work if every application that accesses data does it part, but I haven't seen any proven examples, and it seems to be a highly complex interface that would require some real amazing programming magic. Thanks Dan On Thu, 2008-06-19 at 00:04 -0400, Stephen Johnston wrote: > Thank you. I figured that something of that nature was involved. It's > good to hear some approaches that are actually being used. > > -Stephen
