For those not in the know - Livejournal is an extremely large weblogging site. They were purchased by SixApart not long (as of April 2005) ago.
slides here
"We'll go into what jesus does now, which isn't much." - Brad was talking about one of their servers.
MyISAM does the logging for the site.
InnoDB
wants 64 bit architecture (they're just starting to implement this in November - had a couple of boxes, much trouble to acquire them).
They also use BigIP and mod_proxy for load balancing.
Perlbal - all asynchronous file i/o, load balancer written in Perl. Intended only as proof of concept (he was going to write the implementation in C) but it worked so well they kept it. It's persistent: just send options request to Apache so it doesn't block on kernel accepting a tcp/80 request with no children available.
MogileFS - thumbnails aren't replicated because you can't just regenerate them. Uses sendfile because less CPU - no kernel -> userland -> back to kernel.
Use tmpfs or ramfs to eliminate 32 bit memory allocation issues (??)
They like
this vendor.
Brad really really hates the 2.6 kernel megaraid driver (yeah, so do I, look at swag). He can't tell if a disk is really alive when he's using it.
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MikePatterson - 26 Apr 2005