The pt-online-schema-change issue had a high importance. The bug fix is bug 1188002: pt-online-schema-change causes “ERROR 1146 (42S02): “Table ‘db._t_new’ doesn’t exist”. This happens when the tool’s triggers cannot be dropped. If that occurred, it still dropped the new table, which meant triggers were referencing a missing table, causing errors on write to the original table.
This is handled properly now: if triggers can’t be dropped, then the new table isn’t dropped either. This leaves a half-finished new table, but that’s better than write errors on the original table. Those using pt-online-schema-change should definitely upgrade.
The “pt-query-digest –output json” change now delivers more information. The previous JSON output was minimal; the output as of 2.2.3 is much more extensive and, consequently, has a new structure. This means 2.2.3 pqd –output json is not backwards-compatible (but we warned in the first 2.2 release that –output json would be in flux).
See https://launchpad.net/percona-toolkit/+milestone/2.2.3 for the full list of bugs fixed in Percona Toolkit 2.2.3.
Visit https://www.percona.com/software/percona-toolkit to download Percona Toolkit 2.2.3; it’s also in our main repos.