Moving Sharded Redis Servers

Redis Database

This morning I found that I really needed to move some of my shared redis servers. Due to the needed bandwidth, I've got eight redis servers on one 196GB RAM box, but this morning, I saw that the total RAM in use was over 170GB, and it was causing issues when redis tried to fork and save the data.

This is what I love about redis and this sharding - I can simply shut things down, move the redis dump.rdb files, fire up the servers on the new machines, and everything will load back up and be ready to go. A simple change in the sharing logic to point to the new machine for those moved servers, and everything is back up and running. Very nice.

Yes, it's very manual as well, but sometimes, the costs of that manual configuration are really worth it. Today it paid off. Big.