Hi, I am looking into using memcached for our project. We are not a big web site like many of your users. Instead we are a "scale out" architecture for financial processing.
Our systems use lots of processes (think 100 or more) to crunch away at DB jobs. We currently cache something like 400 MB of data into each of these processes. I would like to move this 400 MB into memcached to reduce our memory footprint. We get a fixed time window to process thousands of jobs. If the cached data needs to be gotten from the DB, we will blow out the time window and have unhappy accountants. One instance of memcached could handle our tiny 400 MB with no problem. It can probably even handle the load of 100 processes hitting it. But I am concerned if memcached went down then we would miss our fixed time window. Ideally we would like to have a few memcached instances each with a full copy of the 400 MB. The Wiki says memcached does not do replication. It seems to me, the client side could send all changes to all instances. Of course the fun starts when an instance goes down, or the network partitions. (Someone mentioned the Amazon Dynamo paper. It gives lots of issues to consider.) Has anyone tried replication with memcached? What has been your experiences? Thanks! Brian Beuning
