From:	Ralf Palsa <rpalsa@eso.org>
Sent:	Friday, February 23, 2018 2:11 PM
To:	Reinhard Hanuschik
Cc:	Burkhard Wolff; Sandra Marķa Castro
Subject:	QC Pipeline life cycle policy

Dear Reinhard,

this is to summarize our agreement on removing old pipeline versions from the QC RPM repositories, 
resulting from our discussion on February, 1st 2018.

The current situation is that QC can have several versions of a pipeline installed on their systems and are 
able to switch between them. The pipeline versions which are available through this scheme are 
constraint by their system dependencies (DFS, CPL, Esorex), i.e. only pipeline versions which depend on 
the same version of the DFS are available simultaneously.

Since the DFS has an annual release cycle this already constrains the life cycle of a pipeline version to 
basically one year.

Old pipeline versions cannot be kept in our build and packaging system for technical reasons (resource 
limitations), but we also need a policy to phase out and remove old pipeline versions from our 
repositories.

With the basic release cycle of the DFS in mind, we agreed on the following policy on top of that DFS life 
cycle:

- If a new version of a pipeline is delivered by a pipeline developer
  to QC for a given version of the DFS, old versions of this pipeline
  for that DFS version are kept in the repositories for another year
  (provided that no DFS upgrade happens before that time).

- After that period old version will, silently, be removed from the
  repository used by IT to install pipeline packages on the QC
  machines, and thus will no longer be available for installation.

  This does *not* mean that an already existing installation of such a
  pipeline is being removed from any of the QC machines.

- If needed it will be possible to extend the life time of a particular
  pipeline version (again, provided that the DFS version is unchanged)
  by one year on request by QC since the old pipeline versions will
  still be kept in our local package pool, they will only be removed
  from the 'publicly' visible RPM repositories.

- This scheme will be implemented starting on April, 1st 2018.


If there is anything that I forgot, please let me know.

Best regards,
Ralf