August 7, 2008 1 Comment
The High Scalability blog has a good summary of a presentation given by Farhan Mashraqi of Fotolog.
As I have written before, I am really, really, really ambivalent about using memcached to cache data coming out of MySQL.
Fotolog has 51 instances of memcached on 21 servers with 175G in use and 254G available.
I can’t help but wonder how MySQL would perform if given 21 extra servers with all that memory.
They also mention MySQL’s cache, my advice on that is don’t even bother with it, it is worse than useless.
One place where I was interested in their use of memcached is in caching filesystems accessed via NFS. Again I have to ask whether they are solving the wrong issue. It is a bit like saying “my car is slow therefore I will buy a faster car to tow it with, and my slow car will now go faster.” The real solution is to see why your car is slow in the first place, and then trade it in for a faster one if need be.