When should I “Release” my builds?

问题:

We just started using Visual Studio Release Management for one of our projects, and we're already having some problems with how we are doing things.

For now, we've created a single release stage, which is responsible for deploying our build artifacts to a dedicated virtual machine for testing. We intend to use this machine to run our integration tests later on.

Right now, we have a gated checkin build process: each checkin fires all the unit tests and we configured the release trigger to happen on this build also. At first, it seemed plausible that, after each checkin, the project was deployed and the integration tests were executed. We noticed that all released builds were polluting the console on Release Management, and that all builds were being marked as "Retain Indefinitely" and our drop folder location was growing fast (after seeing that, it makes sense that the tool automatically does this, since one could promote any build to another stage and the artifacts need to be persisted).

The question then is: what are we doing wrong? I've been thinking about this and it really does not make any sense to "release" every checkin. We should probably be starting this release process when a sprint ends, a point that can be considered a "release candidate".

If we do that though, how and when would we run our automated integration tests? I mean, a deployment process is required for running those in our case, and if we try to use other means to achieve that (like the LabTemplate build process) we will end up duplicating deployment code.

What is the best approach here?

回答1:

It's tough to say without being inside your organization and looking at how you do things, but I'll take a stab.

First, I generally avoid gated checkin builds unless there's a frequent problem with broken builds. If broken builds aren't a pain point, don't use gated checkin. Why? Simple: If your build/test process takes 10 minutes to run, that's 10 minutes that I have to wait to know whether I can keep working, or if I'm going to get my changes kicked back out at me. It discourages small, frequent checkins and encourages giant, contextless checkins.

It's also 10 minutes that Developer B has to wait to grab Developer A's latest changes. If Developer B needs that checkin to keep working, that's wasted time. Trust your CI process to catch a broken build and your developers to take responsibility and fix them on the rare occasions when they occur.

It's more appropriate (depending on your branching strategy) to do a gated checkin against your trunk, and then CI builds against your dev/feature branches. Of course, that opens up the whole "how do I build once/deploy many when I have multiple branches?" can of worms. :)

If your integration tests are slow and require a deployment to succeed, they're probably not good candidates to run as part of CI. Have a CI/gated checkin build that just:

• Builds
• Runs fast unit tests
• Runs high-priority, non-deployment-based integration tests

Then, have a second build (either scheduled, or rolling) that actually deploys and runs the whole test suite. You can schedule it according to your tastes -- I usually go with one at noon (or whatever passes for "lunch break" among the team), and one at midnight. That way you get a tested build from the morning's work, and one from the afternoon's work.

Using the Release Default Template, you can target your scheduled builds to just go as far as your "dev" (/test/integration/whatever you call it) stage. When you're ready to actually release a build, you can kick off a new release using that specific build that targets Production and let it go through all your stages normally.

回答2:

Don't get tripped up on the 'Release' word. In MS Release Management (RM), creating a Release does not necessarily mean you will have this code delivered to your customers / not even that it has the quality to move out of dev. It only means you are putting a version of the code on your Release Path. This version/release can stop right in the first stage and that is ok.

Let's say you have a Release Path consisting of Dev, QA, Prod. In the course of a month, you may end up releasing 100 times in Dev, but only 5 times in QA and once in Prod.

You should drive to get each check-in deployed and integration tested. If tests takes a long time, only do the minimal during (gated or not) check-in (for example, unit tests + deployment), and the rest in your second stage of Release Path (which should be automatically triggered after first stage completes). It does not matter if second stage takes a long time. As a dev, check-in, once build completes successfully (and first stage), expect the rest to go smoothly and continue on your next task. (Note that only result of the first stage impacts your TFS build).

Most of the time, deployment and rest will run fine and so there won't be any impact to dev. Every now and then, you will have a failure in first stage, now the dev will interrupt his new work and get a resolution asap.

As for the issue that every build is kept indefinitely, for the time being, that is a side effect of RM. Current customers need to do the clean up manually (or script it). In the coming releases, a new retention policy for releases/builds will be put in place to improve this. This has not been worked on yet, but the intention would be to, for example, instruct RM to keep all releases that went to Prod, keep only the last 5 that went to QA and keep only the last 2 that went to Dev.

回答3:

This is not a simple question, so also the answer must be articulated.

First of all, you will never keep all of your builds; the older a build, the less interesting to anyone; a build that doesn't get deployed in production is overtaken by builds that reaches that stage.

A team must agree on the criteria that makes a build interesting to keep around and how long to keep it. Define a policy for builds shipped to production or customers: how long do you support them? Until the next release, until the following one, for five years? Potentially shippable builds, still not in your customers' hands, are superseded by newer, so you can use a numeric or a temporal criteria (TFS implements only the first, as the second is more error-prone). Often you have more than one shippable build, when you want a safety net option and being able select from a pool which deliver (the one with more manageable bugs).

The TFS "Retain Indefinitely" should be used when you cannot automate the previous criteria, so you switch to a manually implemented policy. Indefinitely is not forever, means for an unknown time interval.