This is version 2.3 of the AWS Elemental Delta documentation. This is the latest version. For prior versions, see the Previous Versions section of AWS Elemental Delta Documentation.
Downgrades in AWS Elemental Delta
This section describes how to downgrade the software version of an existing Delta installation.
Important
To avoid service interruptions, perform downgrades during a maintenance window! All traffic to and from an AWS Elemental Delta node stops while the node is being downgraded.
When you're downgrading AWS Elemental Delta nodes, the basic command remains the same regardless of how many nodes you have. The command you use is this:
[elemental@hostname ~]$ sudo sh ./elemental_production_delta_<version>.run –-skip-all –xeula --start --downgrade --restore-db<path/to/database/backup>
Where version is the software version that you're downgrading
to, such as 2.1.4.123456. Finding the path/to/database/backup is part
of the downgrade steps.
If you have a cluster of nodes, though, they must be downgraded in a specific order, and there might be extra steps needed. For this reason, this section includes separate topics for the different kinds of clusters.
We support downgrades up to two major versions back. With AWS Elemental Delta version 2.3.x, you can perform a standard downgrade to versions 2.2.x and 2.1.x. Note that there may be special consideration for downgrades to versions 2.1.0 through 2.1.2. For more information about these considerations, see the following section.
Downgrade Special Consideration
Because of the way the installers are configured, if the you meet the conditions for special consideration, you have to first downgrade to version 2.1.3 before going to an earlier version.
The special consideration applies to you if you're downgrading to version 2.1.2, or 2.1.1 and your nodes have previously been on version 1.7.x or earlier.
Topics
