Notes

At the moment, my top 3 tools to tune MySQL are:

• mysqlreport: a friendly report about the status of your MySQL server (or SHOW STATUS for real persons);
• innotop: a top-like program to see what's going on with your MySQL server (works with multiple servers);
• mysqlsla: analyses MySQL statement logs (including slow queries).

Other tools are also useful sometimes:

• Duplicate Index Checker: checks your indexes to see if you have multiple indexes covering the same information, in the same order;
• MySQL Query Profiler: reports on what work MySQL will have to do for a given batch of queries.

I discover most of this tools reading the Xaprb blog, recommended.