Database Upgrade Methods

Dump and Restore

This upgrade method is relatively simple and reliable and often allows upgrades across multiple major versions at once. However it also tends to require the most downtime to complete.

It works by dumping the data from the existing Database and restoring it to a target Database, running the desired version.

Supported Database Types

All database types support this upgrade method in some form.

Process

  1. Create a new target Database running the desired version.
  2. Scale Services that use the existing Database down to zero containers. While this step is not strictly required, it ensures that the containers don't write to the Database during the upgrade.
  3. Dump the data from the existing Database to the local filesystem.
  4. Restore the data to the target Database from the local filesystem.
  5. Update all of the Services that use the original Database to use the target Database.
  6. Scale Services back up to their original container counts.

Guides

Replication

Upgrading using replication is a little more complex than the dump and restore method but only requires a fix amount of downtime regardless of the Database's size. This makes it is a good option for large, production Databases that cannot tolerate much downtime.

It works by creating an upgrade replica of the existing Database and updating all Services that currently use the existing Database to use the replica.

Supported Database Types

PostgreSQL Databases are currently the only ones that support this upgrade method.

Guides

Upgrading In-Place

Upgrading Databases in-place is similar to a "traditional" upgrade where, rather than replacing an existing Database instance with a new one, the existing instance is upgraded itself. This means that Services don't have to be updated to use the new instance but it also makes it difficult or, in some cases, impossible to roll back if you find that a Service isn't compatible with the new version after upgrading.

Additionally, in-place upgrades generally don't work across multiple major versions so the Database must be upgraded multiple times in situations like this.

In-place upgrades must be performed by an Aptible team member.

Supported Database Types

MongoDB and Redis have good support for in-place upgrades and, as such, can be upgraded fairly quickly and easily using this method.

ElasticSearch / ElasticSearch 7+ can generally be upgraded in-place but there are some exceptions:

  • ES 6.X and below can be upgraded up to ES 6.8
  • ES 7.X can be upgraded up to ES 7.10

ES 7 introduced breaking changes to the way the Database is hosted on Aptible so ES 6.X and below cannot be upgraded to ES 7.X in-place.

PostgreSQL supports in-place upgrades but the process is much more involved. As such, in-place upgrades for PostgreSQL Databases are reserved for when none of the other upgrade methods are viable.

Guides


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