Run a Pipeline on a Specific Commit¶

Sometimes you need to see the result of merging different commits to analyze and identify correct combinations and potential flows in data collection and processing. Or, you just want to rerun a failed job manually.

Pachyderm enables you to run your pipelines with old commits or in different handpicked combinations of old commits that are stored in separate repositories or branches. This functionality is particularly useful for cross-pipelines, but you can also use it with other types of pipelines.

For example, you have branches A, B, and C. Each of these branches has had commits on it at various times, and each new commit triggered a new job from the pipeline.

Your branches have the following commit history:

• Branch A has commits A1, A2, A3, and A4.
• Branch B has commits B1 and B2.
• Branch C has commits C1, C2, and C3.

For example, you need to see the result of the pipeline with the combination of data after A4, B1, and C2 were committed. But none of the output commits were triggered on this particular combination.

To get the result of this combination, you can run the pachctl run pipeline cross-pipe command.

pachctl run pipeline cross-pipe A4 B1 C2

This command triggers a new job that creates a commit on the pipeline's output branch with the result of that combination of data.

Because A4 is the head of branch A, you can also omit the A4 commit in the command and specify only the C2 and B1 commits:

pachctl run pipeline cross-pipe C2 B1

Pachyderm automatically uses the head for any branch that did not have a commit specified. The order in which you specify the commits does not matter. Pachyderm knows how to match them to the right place.

Also, you can reference the head commit of a branch by using the branch name.

pachctl run pipeline cross-pipe A B1 C2

This behavior implies that if you want to re-run the pipeline on the most recent commits, you can just run pachctl run pipeline cross-pipe.

If you try to use a commit from a branch that is not an input branch, pachctl returns an error. Similarly, specifying multiple commits from the same branch results in error.

You do not need to run the pachctl run pipeline cross-pipe command to initiate a newly created pipeline. Pachyderm runs the new pipelines automatically as you add new commits to the corresponding input branches.