Planning Your Upgrade
AEM Upgrade Overview
AEM is often used in high impact deployments that might serve millions of users. Usually, there are custom applications that are deployed on the instances, which add to the complexity. Any effort to upgrade such a deployment needs to be handled methodically.
This guide helps with establishing clear goals, phases, and deliverables when planning your upgrade. It focuses on overall upgrade execution and guidelines. While it provides an overview of the actual upgrade steps, it refers to available technical resources where suitable. It should be used with the available technical resources referred to in the document.
The AEM Upgrade process needs carefully handled planning, analysis, and execution phases with key deliverables defined for each phase.
NOTEIt is important to ensure that you are running a supported operating system, Java™ runtime, httpd, and Dispatcher version. For more information, refer the technical requirements for AEM 6.5 LTS. Upgrading these components must be accounted for in your upgrade plan and should take place before upgrading AEM.
Upgrade Phases
Much work goes into planning and running an AEM upgrade. To clarify the different efforts that go into this process, Adobe has broken down the planning and execution exercises into separate phases. In the sections below, each phase results in a deliverable that is often used by a future phase of the upgrade.
Creating a Test Plan
Each customer’s implementation of AEM is unique and has been customized to meet their business requirements. As a result, it is important to determine all the customizations that have been made to the system so that they can be included in a test plan.
The exact production environment needs to be duplicated and testing should be performed on it after the upgrade to make sure all applications and custom code still run as desired. Regress all your customization and run performance, load, and security testing. When organizing your test plan, make sure to cover all customizations that have been made to the system in addition to out of the box UIs and workflows that are used in your day to day operations. These can include custom OSGI services and servlets, integrations to the Adobe Experience Cloud, integrations with third parties through AEM connectors, custom third-party integrations, custom components and templates, custom UI overlays in AEM, and custom workflows. Aditionally, custom queries should still be tested to ensure that their indexes are continuing to work effectively after upgrading.
Assessing Upgrade Complexity
Due to the wide variety in the amount and nature of customizations that Adobe customers apply to their AEM environments, it is important to spend some time up front to determine the overall level of effort that should be expected in your upgrade. AEM Analyzer for AEM 6.5 LTS can help you in assessing the complexity of the upgrade.
The AEM Analyer for AEM 6.5 LTS should give you a fairly accurate estimate of what to expect during an upgrade for most cases. However, for more complex customizations and deployments where you have incompatible changes, you can upgrade a development instance to AEM 6.5 LTS according to the instructions in Performing an In-Place Upgrade. Once complete, perform some high-level smoke testing on this environment. The goal of this exercise is not to exhaustively complete the test case inventory and produce a formal inventory of defects, but to give us a rough estimate of the amount of work that will be required to upgrade the code for AEM 6.5 LTS compatibility. When combined with the AEM Analyzer and the architectural changes that were determined in the previous section, a rough estimate can be provided to the project management team for planning the upgrade.
Building the Upgrade and Rollback Runbook
While Adobe has documented the process for upgrading an AEM instance, each customer’s network layout, deployment architecture, and customizations require fine-tuning and tailoring of this approach. For this reason, Adobe encourages you to review all the provided documentation and use it to inform a upgrade-specific runbook that outlines the specific upgrade and rollback procedures that you will be following in your environment.
Adobe has provided upgrade and rollback procedures in Upgrade Procedure and step-by-step instructions for applying the upgrade in Performing an In-Place Upgrade. These instructions should be reviewed and considered with your system architecture, customizations, and downtime tolerance to determine the appropriate switch-over and rollback procedures that you will be executing during the upgrade. Any changes to architecture or server sizes should be included when drafting your customized runbook.
Developing an Upgrade Plan
The output from the previous exercises can be used to build an upgrade plan covering the expected timelines for your test or development efforts, and actual upgrade execution.
A comprehensive project plan should include:
- Finalization of development and test plans
- Upgrading development and QA environments
- Updating the custom code base for AEM 6.5 LTS
- A QA test and fix cycle
- Upgrading the staging environment
- Integration, performance, and load testing
- Environment certification
- Go live
Performing Development and QA
Adobe has provided procedures for Upgrading Code and Customizations to be compatible with AEM 6.5 LTS. As this iterative process is run, changes should be made to the runbook as needed.
The development and testing process is usually an iterative one. As issues are discovered that require adjustments to the upgrade process, make sure to add them to your custom upgrade runbook. After several iterations of testing and fixing, the code base should be fully validated and ready for deployment to the staging environment.
Final Testing
Adobe recommends a final round of testing after the codebase has been certified by your organization’s QA team. This round of testing will involve validating your runbook on a staging environment followed by rounds of user acceptance, performance, and security testing.
This step is vital as it is the only time that you are able to validate the steps in the runbook against a production-like environment. Once the environment has been upgraded, it is important to allow end users some time to log in and go through the activities they do when using the system in their day-to-day activities. Finding and correcting issues in these areas before go-live can help to prevent costly production outages.
Performing the Upgrade
Once final sign-off has been received from all stakeholders, it is time to execute on the defined runbook procedures. Adobe has provided steps for upgrade and rollback in Upgrade Procedure and installation steps in Performing an In-Place Upgrade as a reference point.
Adobe has provided some steps in the upgrade instructions for environment validation. These include basic checks like scanning the upgrade logs and verifying that all OSGi bundles have properly started, but Adobe recommends also validating with your own test cases based on your business processes. Adobe also recommends checking the schedule of AEM’s Online Revision Cleanup and related routines to ensure that they will be occurring during a quiet time for your company. These routines are essential to the long-term performance of AEM.
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