On a Hudson master node, what are the .tmp files created in the workspace-files folder?

Question

Question:

In the path HUDSON_HOME/jobs/<jobname>/builds/<timestamp>/workspace-files, there are a series of .tmp files. What are these files, and what feature of Hudson do they support?

Background

Using Hudson version 1.341, we have a continuous build task that runs on a slave instance. After the build is otherwise complete, including archiving the artifacts, task scanner, etc., the job appears to hang for a long period of time. In monitoring the master node, I noted that many .tmp files were being created and modified under builds//workspace=files, and that some of them were very large. This appears to be causing the delay, as the job completed at the same time that files in this path stopped changing.

Some key configuration points of the job:

• It is tied to a specific slave node
• It builds in a 'custom workspace'
• It runs the Task Scanner plugin on a portion of the workspace to find "todo" items
• It triggers a downstream job that builds in the same custom workspace on the same slave node

Answer 1

In this particular instance, the .tmp files were being created by the Task Scanner plugin. When tasks are found, the files in which they are found are copied back to the master node. This allows the master node to serve those files in the browser interface for Tasks.

Per this answer, it is likely that this same thing occurs with other plug-ins, too.

Plug-ins known to exhibit this behavior (feel free to add to this list)

1. Task Scanner
2. Warnings
3. FindBugs

Answer 2

There's an explanation on the hudson users mailing list:

...it looks like the warnings plugin copies any files that have compiler warnings from the workspace (possibly on a slave) into a "workspace-files" directory within HUDSON_HOME/jobs//builds/

The files then, I surmise, get processed resulting in a "compiler-warnings.xml" file within the HUDSON_HOME/jobs//builds/

I am using the "warnings" plugin, and I suspect it's related to that.