Split CloudFormation Stacks

This page tells you how to convert a master stack system into a split stack system.

Rationale

A Datomic Cloud system comprises at least 2 CloudFormation stacks per AWS best practice guidelines:

  • one storage resource stack
  • one or more compute stacks

In the AWS Marketplace install, these stacks are nested under a master stack. This master stack is necessary for Marketplace integration, but it is not necessary for Datomic itself. More importantly, the master stack makes various operational tasks more difficult.

For production operation, you should use a split stack system, i.e. separate top-level storage and compute stacks.

There are two ways to run a split stack system:

  • Create a split stack system from scratch.
  • Convert a master stack system into a split stack system, per the instructions below.

How To Split Datomic Stacks

The following steps convert a Datomic system from the master stack setup to the split stack setup. There are three steps:

Delete the master stack

Deleting the master stack will make your system temporarily unavailable, but does not harm your data!

  1. Select the root stack for your system in the CloudFormation console. The root stack will have a Stack Name that is the same as your system name.
  2. Click "Delete" from the menu bar. Confirm this in the Delete Stack popup, then wait for the stack deletion to complete. This can take 10 minutes or more.

Recreating Stacks

The process of recreating the stacks is the same as starting a new split stack system with the following exceptions:

  • Storage stack name is the name of the system which you just deleted.
  • Reuse existing storage must be set to "True"

The split stack instructions are annotated where necessary for recreating your stack.