Monday, December 12, 2022

Free Page Consumption by InnoDB Table Compression (Percona backoff Algo. part #2)

In my previous post about InnoDB Stalls on Empty Free List, I used a test environment that might look a little artificial : a table larger than the InnoDB Buffer Pool but fitting in the Linux Page Cache.  This configuration allows serving very quickly what MySQL thinks are IOs because these are hit in the filesystem cache.  In this post, I explain why this environment is not totally artificial and can be a good representation of another more complex environment.  I also explain how an Empty Free List backoff stall can occur when no IO is done.  You have probably already guessed what this post is covering from the title, so let's dive in.