On Wed, Jan 17, 2007 at 10:58:09AM -0500, Mark Stosberg wrote:
> 
> Unfortunately, I found the pgmemcache docs lacking. I think I need
> something like a flow chart with the application, the cache store and
> the DB, showing how data gets in and out of the cache and is used by the
> application.

I think Elein (valena.com) has used this; perhaps you should talk to
her.  She might be able to help you out with this.

> Consider the 'memcache' instance gets a machine of its own, I'm also led
> to wonder: Could it make sense to use pgmemcache on it's own for a
> web-app, in place of slony+load-balancing, which seems more complex?

I think that they're solving different problems, really, since slony
is intended as much for insurance as for load reduction.  I have no
doubt that using memcache for some cases is going to be a better
answer than adding another database.

> with synchronization seem like they are less tenuous:  A broken cache
> can always be fixed by deleting it and starting fresh. With slony, there
> seems like a bigger penalty for that.

Yes, but slony also is designed for safety, so that breakage should
be harder to achieve.  (That is not historically true of all the
replications systems, BTW.)  Since its use cases are different than
pgmemcache, though, it's unlikely to be as fast as the single-purpose
tool.

A

-- 
Andrew Sullivan  | ajs at crankycanuck.ca
This work was visionary and imaginative, and goes to show that visionary
and imaginative work need not end up well. 
		--Dennis Ritchie