Keeping two jenkins server in sync

Question

I have

• a usual jenkins master jettysburg:8888/jenkins,
• and a failover jenkins master jettyperry:8888/jenkins.

I am planning to use mercurial to keep the jobs directory of the two masters in sync.

Usually, most of the time, new jobs and builds are defined and executed at jettysburg:8888. Then I would need to sync jettyperry:8888 with whatever took place in jettysburg:8888, and I plan to perform the push once a day.

Which means, after a failover to jettyperry:8888, the push would be performed the converse direction.

I have been using mercurial for my non-programming/coding files (like word, excel and text files) for that purpose, as a means to perform incremental and redundant backup of my "mission critical" files, as well as versioning them.

I am also hoping to depend on mercurial to backout from changes made to jenkins jobs.

Is using mercurial to sync two Jenkins masters a good idea? Is there a better way to keep two Jenkins servers in sync? In this case, I am syncing only the jobs tree.

Answer 1

As long as you don't need shared job state between the servers (they run in their own little universes) and you keep the same plugin modules and libraries on both Jenkins servers, using some form version control to keep the actual job definitions is fine.

My office does this with git. We have a development and a production set of jenkins servers. We maintain a base linux image with jenkins install with all necesarry modules and locally install libraries (like nodejs and such). We then spin up an instance of the image and pull down the jobs.

The one thing that can be a challenge is keeping in sync things like credentials and Jenkins config settings--you might need to keep them as part of the base image.

If you need the job queues to persist and be shared (like a master-master setup) you can look at this plugin, which allows multiple jenkins masters to share the same job queue: https://wiki.jenkins-ci.org/display/JENKINS/Gearman+Plugin