Downgrade Percona Server for MySQL¶

Topic type: Concept

Review Get help from Percona for ways that we can work with you.

Need help planning a downgrade? Percona Support can assist .

Before you downgrade¶

Review the following prerequisites before starting a downgrade:

Understand the Percona Server for MySQL release model. Percona ships Long-Term Support (LTS) releases and bug-fix releases within each LTS series.
Treat hot fixes as separate releases when you plan a downgrade.
For a replication topology, perform a rolling downgrade. Apply a single-server method to each server in turn.
Take a verified backup before any downgrade attempt.
Do not attempt to downgrade below 8.4. Earlier paths are not supported.

For the underlying MySQL guidance, see Downgrading MySQL .

Identify a supported downgrade path¶

The following table summarizes supported downgrade paths from 9.7 LTS.

Downgrade path	Example	Supported methods	Notes
Within the same LTS series	9.7.y LTS to 9.7.x LTS	In-place, logical dump and load, MySQL Clone, or replication	Same-LTS downgrades have the most flexibility.
To the previous LTS series	9.7.x LTS to 8.4.y	Logical dump and load, or replication	Use this path as a rollback only. The data must contain no features from the upgraded version.

Rollback constraint

Cross-series paths fit a rollback scenario only. If you have run any feature unique to 9.7 against the data, do not use a cross-series downgrade. Restore from a pre-upgrade backup instead.

Choose a downgrade method¶

The following methods support the paths in Identify a supported downgrade path:

In-place: stop the server, replace binaries, and restart with the existing data directory. Available within the same LTS series only.
Logical dump and load: export the data with mysqldump and load the dump into the older version.
MySQL Clone: clone data between servers within the same LTS series.
Replication: configure replication from 9.7 to the older version, validate the replica, and cut traffic over.

For cutover and validation guidance during a downgrade, see Upgrade strategies.

Assess downgrade risks¶

Data loss risk

A failed downgrade can corrupt or destroy data. Create and verify a backup before any downgrade attempt. Restore the backup if the downgrade encounters issues.

The following table lists the risks of downgrading.

Risk	Description
Data loss	Data loss is possible if the downgrade encounters issues. Create a backup of your data before attempting a downgrade.
Incompatibility	Features used in the upgraded version can cause incompatibility.
Performance	Downgrading can reduce performance.
Security	Older versions lack security updates available in upgraded versions, which can increase exposure.