Brian Moon brianm at
Thu May 24 03:49:21 UTC 2007

Ian wrote:
> 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.


Brian Moon
Senior Developer
It's good to be cheap =)

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