App Versions

When you update an application by pushing new code or modifying settings, Helion Stackato keeps track of the changes and allows you to rollback to previous versions using the App Versions interface in the Management Console or stackato rollback command.

Each change is assigned a version number, starting with "v1" for the first push, and a short description summarizing the change (for example, pushed new code, changed memory to 512MB). The number of versions available for rollback will depend on the number of code changes made and the Total Droplets limit in the organization's quota plan.

Using App Versions

To view the list of tracked versions for an application:

To rollback to a previous version:

App Version Cutover

When a code push, a settings change, or a rollback happens the current version of the application continues serving requests until the new version is up and able to respond. There is no down time during the switch to the new version.

Saved Droplets

Each code change to an application (stackato push) results in the creation of a new "droplet" containing the packaged application. The system keeps a certain number of these droplets (5 per application in the "default" quota plan) in a "most recently used" list.

When the droplet limit is exceeded, the oldest (least recently used) droplet is removed to make way for the new droplet.

If an admin reduces the number of saved droplets in the quota plan, excess droplets for each application will be culled (starting with the oldest) when a code change is next pushed for that application.

Version Rotation

An app's version is the combination of its droplet and its settings.

Helion Stackato can track an infinite number of settings changes, but keep only a finite number of droplets. When a droplet is removed from the MRU list, app versions which depend on it are also removed from the list.