Establish and Document the Application's Deployment, Instantiation, and Rollback Procedures

This chapter explains how to establish and document how an Application is deployed into an environment, how it is started, and how a Deployment is reversed if it fails.

Definitions

Deployment is the governed technical movement, installation, configuration, activation, publication, or implementation of Release content into a target IT Operating Environment.

Instantiation is the act of starting an Application’s deployed content within an IT Operating Environment Instance so that it runs as one or more in-computer-memory processes, thereby creating or activating an Application Instance.

One Release, Many Deployments

A single Release is typically deployed many times on its way to Production: into test, staging, and Production environments, and into each Instance within them.

Establish the Deployment, Instantiation, and Rollback Procedures

Establish, with the IT Application Owner, the Development or Engineering Organization, and the Operations and Support Team(s):

• Deployment procedure: the steps to deploy a Release into each type of environment, including prerequisites, the packages to deploy, the environment-specific configuration to apply, data changes such as database migrations, and the order of steps where the Application has several components.

• Instantiation procedure: how the Application is started, stopped, and restarted in each Instance, in what order its components start, and how to confirm it is running correctly.

• Verification: the checks that confirm a Deployment succeeded, such as smoke tests and health checks.

• Rollback and remediation: how to reverse a failed Deployment, including how to restore the previous Release and any data it changed, the conditions that trigger rollback, and who decides. Where a change cannot be rolled back, for example an irreversible data migration, establish the alternative remediation in advance.

Rehearse the procedures in Pre-Production Staging before they are used in Production.

Document and Share the Procedures

Record the Deployment, Instantiation, verification, and rollback procedures in the Release and Deployment section and the Operational section of the Application Documentation, with Instance-specific differences recorded explicitly. Where procedures are automated, link to the automation and document what it does and how to intervene if it fails. Update the procedures with every Release that changes them.

Best Practice: Establish and Document the Application’s Deployment, Instantiation, and Rollback Procedures

It is a best practice to both establish and document the solution for getting each Release safely into, and if necessary out of, every environment: define how the Application is deployed, started, verified, and rolled back, rehearse those procedures before Production, and record them with their Instance differences.

Benefits: Documented and rehearsed procedures make Deployments predictable and failures recoverable, reducing both the likelihood and the duration of Deployment-related outages. Establishing rollback and remediation in advance means that when a Deployment fails, the team acts on a known plan instead of improvising under pressure.

Common Antipatterns

Connections to Related IF4IT Practices and Inventories

The Release Management Best Practices addresses the distinction between a Release and its many Deployments, and rollback and remediation planning. The IT Operating Environments Best Practices addresses how Releases are promoted across environments.