Recently we had encountered a strange issue with replication and temp directory(tmpdir) change while working for one major client.
All the servers under this were running with Percona flavor of MySQL versioned 5.6.38 hosted on a Debian 8(Jessie)
The MySQL architecture setup is as follows one master with 5 direct slaves under it
Through this blog, we will take you through the issue we had faced and how we fixed ultimately.
There was a simple request from our client to add a column and index to a 16GB production table since the table had foreign keys, to avoid complications we decided to go with online DDL instead of pt-online-schema.
When we started to alter, it got failed due to insufficient space in “tmpdir”.MySQL by default would be using “/tmp” for temp table creating, sorting and other temp operation, Since we had only 5.7G left on the “/” …[Read more]