MySQL replication stopped due to a disk full situation on MySQL server. Here are notes on how I repaired it.
How to purge old unnecessary MySQL binary log files on DB master, after checking replication status.
Notes on how to set up MySQL replication.
If a MySQL application uses many tables containing TEXT columns, then for various JOIN and GROUP BY operations on these tables, MySQL cannot use in-memory temporary tables and need to resort to using on-disk ones. The in-memory vs on-disk speed difference is considerable in these cases. Introducing a special in-memory temporary file system can speed performance by a factor of 10x or more.