Let's perform the following steps to recall an upgrade and bring your application status to a previous revision:

1. List the revision history for your release, in our example, coy-jellyfish:

$ helm history my-mysqlrelease
REV UPDATED                 STATUS     CHART       DESCRIPTION
1   Tue Oct 1 22:47:37 2019 SUPERSEDED mysql-1.3.3 Install complete
2   Tue Oct 1 22:57:32 2019 SUPERSEDED mysql-1.3.3 Upgrade complete
3   Tue Oct 1 23:00:44 2019 SUPERSEDED mysql-1.2.0 Upgrade complete
4   Tue Oct 1 23:07:23 2019 SUPERSEDED mysql-1.3.3 Upgrade complete
5   Tue Oct 1 23:10:39 2019 DEPLOYED   mysql-1.2.0 Upgrade complete

2. Let's say you need to roll back from the last upgrade to revision 4. Roll back to a specific revision:

$ helm rollback my-mysqlrelease 4
Rollback was a success.

3. The revision history will be updated to reflect your rollback:

$ helm history my-mysqlrelease
 REV UPDATED                  STATUS     CHART       DESCRIPTION
...
 5   Tue Jul 30 22:44:07 2019 SUPERSEDED mysql-1.2.0 Upgrade complete
 6   Tue Jul 30 23:11:52 2019 DEPLOYED   mysql-1.3.0 Rollback to 4

Now you have learned how to review the release history and roll back a Helm release when needed.