Jilles’ weblog

Lately a discussion on the memcached-mailing list has started where for example the guys behind facebook.com and bloglines.com are participating and sharing some of their experiences. I’m don’t think this is rocket science, but I’d like to quote some of the things that are being said and provide some links to the relevant discussions.

About the general “would you want to bet your uptime on memcached as an infrastructure component?”-question:

We consider memcached a critical part of our infrastructure. The benefit of memcached in a typical setup is to reduce the amount of database hardware you need to support an application; if you have enough database horsepower to run unimpaired with most of your memcached servers out of service, then there¹s probably no point using memcached at all, since it without a doubt adds extra complexity to your application code. [link]

If you shard all you data, etc. etc., is memcached still worth it?

Question:
And you would split (federate) your database into 100 chunks (the remaining 100 would be hot spares of the first 100 and could even be used to serve reads), wouldn’t that take care of all your database load needs and pretty much eliminate the need for memcache? Wouldn’t 50 such boxes be enough in reality?
Answer:
Don’t forget about latency. At Hi5 we cache entire user profiles that are composed of data from up to a dozen databases. Each page might need access to many profiles. Getting these from cache is about the only way you can achieve sub 500ms response times, even with the best DBs. [link]

Also, there is a lot of talk about a FUSE (File system in user space) filesystem based on top of memcached. Not only would that make caching available for those applications you do not control (blackbox) but it would have some really great advantages for your generic PHP app:

Over the last two weeks i spent a lot of time discussing a memcachefs (fuse-based) with two fellow geeks - applications that came to mind were (a) the smarty cache (b) php sessions; for both cases, losing files (as a whole, not random parts inside) is ok and readdir is irrelevant, which allows cutting a lot of corners. [link]

Terry Chay over at “The Woodwork” has a length but nicely written blog post about a PHP vs Ruby on Rails discussion. If you’re interested in that kind of stuff, read the article: it has some juicy humor sprinkled into it as well; it’s a bit flame bait too…

Favourite quote (quoting another quote):

“First they ignore you, then they laugh at you, then they fight you, then you win.”
—Mahatma Ghandi

OSCON 2005:

“Unless you’re Ruby.”
—Danny O’Brien, “On Evil”

And:

I can’t speak for Alex, but what I’m saying is look at the top 100 websites on the internet: about 40% of them are written in PHP and 0% of them are written in Rails. (Yes, I can (and am) using this statistic to grind you Ruby fuckers into the dust.)

Just watched the Lost season finale and I must say I absolutely loved it. So many variables, plots, and personalities changing around in the matter of an hours worth of television. I am one of the Lost-fans that actually liked pretty much all the episodes since the beginning — but even those that didn’t like the last season too much were blasted away by this seasons’ finale.

One interview that I’ve spotted online with Damon Lindelof is pretty interesting if you’d like a few answers to the many questions being posed by the finale.

Only 48 more episodes to go, since the show is slated to end in 2010!