brianm at dealnews.com
Thu May 24 03:49:21 UTC 2007
> I do have one more question, but feel free to ignore it if I'm bugging you.
> What is the point of the automatic failover php has by default?
> If there is an error getting/adding to the memcached server, and it
> fails over to another, wouldn't there be duplicates then? Because it
> would be adding the same key to more than 1 server in the connection pool?
Well, yes, there would be two copies assuming the failed server is still
up and running. Usually, when we have hit this issue, a server has
died. Also, we don't cache anything more than a day and most things no
more than an hour. So, at worst, there are two copies out there for an
hour. If you have a system that is actively adding and deleting data
from memcached, this could be an issue. You could write a custom script
that connects to all servers and deletes the key on each server. If
your application can deal with a downed node, you can set
memcache.allow_failover in your php.ini to No.
It's good to be cheap =)
More information about the memcached