Date: 04/28/08 (MySQL Communtiy)    Keywords: mysql, database, sql

Greetings,

We will be upgrading to MySQL 5.0 (either 5.0.58 or 5.0.60 when it becomes available) 4.1 this summer and we are considering using DRDB. My concerns, as the dba are:

1. Failover time. We are currently running a single, monolithic InnoDB database that has grown to 342G. When I shutdown the server it has taken as long as 40 minutes for InnoDB to flush all data to disk. My concern is that with DRDB, if we have a hardware failure on the DRDB master, with DRDB block-level replication, the DRDB slave's datadir and logdir files will be in the same state as the master when it failed and startup of MySQL could take a long time. Currently we are handling failover with replication and scripts to redirect who the master is.

2. Table Maintenance. Some of our tables are quite large. One is at 90GB. To rebuild indexes and defrag tables, I would run ALTER TABLE blah ENGINE=InnoDB on the slave and then failover to it. With DRDB, if I understand it correctly, this would not be possible.

My concerns are that due to the size of our database DRDB may not be the optimal choice. I would appreciate anybody's comments on this.

Source: http://community.livejournal.com/mysql/127896.html