Viewer Integration and Release Processes

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This page describes how Viewer development projects are organized, including the Mercurial (hg) repositories, builds, and the integration and release processes through which changes move to get from the developer (either inside or outside Linden Lab) to the Second Life Viewer.

The ultimate arbiter of these processes is the Viewer Product Team, which is composed of the product managers from Linden Lab groups that are engaged in viewer development. The Viewer Product Team is chaired by the Product Manager of the Snowstorm Team.

There are three core hg repositories (each repository is in effect a branch; the processes described here do not rely on using the hg branching features within a repository):

  • Development is the integration trunk
  • Beta is used to test and stabilize releases and build beta releases
  • Release is used to build official stable releases

all three of these repositories are used by both Linden Lab development teams and open source developers; they are accessible at hg.secondlife.com, but only the specific Linden team responsible for each one has commit access to it. Detailed descriptions of each, and the processes for moving changes between them, are below.

Development

caption="Project and Development repositories/branches"

Location: http://hg.secondlife.com/viewer-development

This is the conceptual ‘trunk’ from which all development, both inside and outside Linden Lab, should be derived.

It is built continuously, with the resulting viewers being publicly available. There are official builds from this repository posted approximately bi-weekly on the “Second Life Development Viewer” channel for the brave or curious, and nightly builds (location TBD) for the really adventurous.

Ordinary development, whether for feature development or bug fixes, pulls from this repository to a Project repository, and tracks all changes made in Development as work is done in that Project repository. Code is pulled back to this repository for integration (see Development Integration Criteria below).

Ideally, any bi-weekly official build from this repository is a candidate for the creation of a new official viewer release.

Project

Location: determined by the development team, but somewhere at hg.secondlife.com is encouraged

Any development, whether a single engineer fixing a minor bug or a large team building a major feature, is done in a Project repository that pulls from Development. Large projects will likely have individual repositories pulling from and pushing to their team Project repository; how this is managed and tracks changes made to Development is under the control of the developer(s) on the project.

There may be any number of other repositories created by project teams or developers either inside or outside Linden Lab; these are Project repositories. The default channel identifier built from these repositories is "Second Life Developer" (projects that plan to make test viewers publicly available, which is encouraged, should change this to a project-specific value in those viewers).

Project repositories may be built as needed by the developers; viewers produced from Project repositories may be made available for public testing at times chosen by the development team.

When development is complete, or reaches an appropriate milestone, changes from a Project repository are pulled back to the Development repository by the Snowstorm Team; see Development Integration Criteria below.

Development Integration Criteria

In order to be eligible to be pulled into the Development repository, the changes in a Project repository must satisfy all of the following criteria:

  1. Functionality must have been reviewed and accepted by the Product Owner
    Review is based on the requirements/user stories defined at the beginning of a sprint, and then at the end of a sprint during Acceptance Testing. For Linden development teams, these checks are the normal sprint reviews, not an additional step. For open source developers, the Snowstorm Team will coordinate these reviews with the appropriate Linden reviewers.
  2. Design and code must have been reviewed by competent reviewers.
    In this context, “competent” means appropriate subject matter experts for the code that is modified. Linden development teams determine for themselves who the competent reviewers are; for open source contributions, the Snowstorm Team will determine the appropriate reviews.
    • If there are changes to code or protocols shared between the viewer and the simulator, those changes must include unit tests that at minimum validate that the behavior before and after the change is compatible. If that is not possible due to the nature of the change, then the change must include documentation on how the interfaces are changed, and the relevant simulator developers must review and approve them (for open source contributions, the Snowstorm Team will coordinate and facilitate these reviews).
  3. There must be a test plan
    The test plan must describe in detail how Integration QA can validate the modified behavior.
  4. The Project repository must have merged in the latest changes from Development.
    The results must be validated by building viewers for all platforms and doing at least minimal viewer testing. Breaking the Development build is considered bad practice and may incur karmic debt.
  5. There must be Contribution Agreements on file from all contributors to the change if the Project repository contains changes made by non-Lindens.

When these criteria have been met, the development team requests that changes be integrated into the Development repository; see How To Submit A Viewer Change.

Beta and Release

When the Viewer Product Team decides that a Development build is a good candidate for creating a general release version, the changes for that build are moved from the Development repository through the Beta and Release repositories following the Beta and Release Process.

caption="Development through Beta to Release"

Beta Repository

Location: http://hg.secondlife.com/viewer-beta

The Integration and QA team pulls from Development into the Beta repository (since the Beta repository will contain only change sets that are already in Development, this pull does not require any merges).
Final QA and stabilization are done using builds from the Beta repository; builds from this repository selected by the Viewer Product Team are released on the “Second Life Beta Viewer” channel.
Any bug fixes on this repository are immediately pulled to the Development repository by the Snowstorm Team.

Release Repository

Location: http://hg.secondlife.com/viewer-release

When the Viewer Product Team decides that a Beta branch is ready for release, the Integration team pulls changes from Beta into the Release repository (this is the only path into the Release repository, so this does not require any merges), where it is tagged and built to produce the viewer released on the “Second Life Release” channel.

Beta and Release Process

When the Viewer Product Team determines that one of the official “Development” builds appears to be ready (low crash rate, general acceptance by the community) it is promoted to an official numbered Viewer release via the following process:

  1. The Snowstorm Team adds a release candidate tag to Development.
  2. The Release Manager
    1. Pulls changes from the release candidate tag on Development to the Beta repository (this should not require any merge).
    2. Builds branch on Beta
    3. Creates a release document that includes test plan information and the list of all the changes included in the build (list of JIRAs, etc). Proper attention to detail during development should make this simple.
    4. Offer build to QA for testing and evaluation
  3. In QA, the integration test team:
    1. Executes the set of test plans for all of the changes included
    2. Performs a general smoke test on overall functionality
    3. Identifies overall quality and level of risk for release
  4. The Viewer Product Team evaluates quality, risk and feature set and decides whether or not to release the build as Beta. Options are:
    • Fail: this beta candidate is rejected and the process starts over at some different tag on Development (step 1).
    • Fix First: specific bugs / issues are identified that must be fixed before ship. These bugs are fixed in the Beta repository.
      • Fixes made to the Beta repository are merged to Development by the Snowstorm Team as soon as they are found to be complete.
    • Ship: the Beta is ready as-is.
  5. Once a build is approved for ship, the Release team does its magic to get the build into the field as a Beta build on the “Second Life Beta Viewer” channel.
  6. Once a Beta is in the field, we watch for new bugs, crash rate, performance, and other data. If the Beta needs further iteration, we might iterate multiple times on the Beta branch (return to step 4).
  7. Once the Viewer Product Team decides the Beta is of sufficient quality to ship as an official viewer, the Release team:
    1. Tags the Beta branch
    2. Pulls from the tag on Beta to Release
    3. Tags and builds from the Release repository.
    4. Releases on the “Second Life Viewer” channel.