About scheduling a build with the Poll SCM build trigger
Poll SCM is a type of build trigger that is supported by HCL VersionVault. Poll SCM attempts to run a build job in Jenkins at a scheduled time.
Overview
You must enter the scheduled time in the UNIX cron format. For more documentation on how to schedule jobs, click ? on the Schedule tab.
- For the first build, there is no other job to compare with, so the build runs whenever it is manually started.
- From the second build onwards, the Poll SCM build trigger always searches for a baseline in the build history to find the most recent baseline available and compares the contents in the baseline with the current contents in the default stream. If there are changes, then it proceeds and builds the stream by creating a baseline. If there are no changes then, it does not proceed with the build.
- There is the possibility that a baseline might not be found in the build history because all the previous builds might have failed before a baseline was created or the build history is deleted. In this case, the Poll SCM build trigger proceeds with the build.
The polled builds are tied to the Create baseline option.
Scenarios
Create baseline option disabled
Create baseline option enabled
When the scheduled timer starts the job but there are no changes since the last build
Because there are no changes since the last build or the last baseline selected, the build does not start, as shown in the following sample log:
When some changes are made to the stream and the scheduler starts up