> Are there any benchmark comparisons between apache::dbi and mysql relay?
I've never heard of this "mysql relay" before. A Google search found this: http://www.firstworks.com/sqlrelay.html Is that it? Looks interesting! > We're planning on having four sql servers, one of them will do all of the > writes to the db and the other three will only be used for reads from the db. > > The data in the db that is doing the writing will be constantly replicated > across the other three machines. Which would be better to use to initiate a > persistent database connection? The main concern we have is having to have > two different database handles open for one script, one to the machine that > does the writing and the other to do the reads. Can Apache::DBI detect this? Apache::DBI can certainly tell the difference between two database handles. It caches based on your connection parameters. For raw performance, you can't beat Apache::DBI. It simply does a hash lookup, and uses an already open connection if there is one. SQL Relay appears to need at least one socket connection to be created at the beginning of each request and torn down at the end. SQL Relay looks like it would scale further though, in situations where the number of open database connections becomes an issue. This is generally not a problem for small sites or sites running databases like Oracle on big iron, but it could be in your situation, using MySQL. Also, SQL Relay claims to have load balancing features between multiple replicated databases. With Apache::DBI, you would need to configure your mod_perl servers to point to specific databases. If you try this thing out, please report back to the list on how it works for you. I think a lot of people here might be interested. - Perrin
