Thursday, April 14, 2016

OSG GRAM Support Ending November 2016

As part of the OSG transition from GRAM to HTCondor-CE technology, OSG Operations and Software teams will stop supporting GRAM CE installations in early November. A site that requests support for GRAM or GRAM-based software will be asked to upgrade to HTCondor-CE instead. However, GRAM packages will remain available for sites that accept full responsibility for operation of GRAM.

Toward that goal, OSG CE convenience meta-packages (e.g., osg-ce-condor) will drop GRAM components starting with the April 12 release of OSG 3.3. The change will affect only new installations that use the osg-ce-* packages — OSG will still ship GRAM software, will document how to install GRAM, and will support GRAM in tools like osg-configure.

Other milestones that will likely occur in early 2017:

* Ending support for GRAM CEs at the OSG pilot factories, which will leave many VOs unable to run at GRAM sites
* Dropping GRAM software from the OSG software stack (starting in OSG 3.4.0)
* Removing GRAM-based code from OSG tools like osg-configure


An OSG CE is the entry point for the OSG to your local resources. At the heart of the CE is the job gateway software, which accepts incoming jobs, authorizes them, and delegates them to your batch system for execution. These days, OSG jobs come from the OSG factories and are really pilot jobs, which in turn run actual end-user jobs. Since OSG started, the Globus GRAM gatekeeper has managed grid jobs, but starting in May 2014, the OSG added another job gateway option — HTCondor-CE — that is built on core HTCondor technology. For many reasons, OSG has decided to migrate all CEs to HTCondor-CE and is today in the midst of this change.

Since August 2014, new CE installs included both HTCondor-CE and GRAM, and since December 2014, HTCondor-CE is the default job gateway software for a new site. Today, HTCondor-CE is on 60 CEs and is the sole job gateway software on many of them; the list of sites that have already migrated includes some of the largest OSG sites, as well as medium and small ones.

This is a significant technical change for OSG, but the good news is that it is well underway and has been going very smoothly for most sites. If you are still running GRAM, please consider migrating to HTCondor-CE as soon as possible (you can run both for a while, if you like). Then, once your HTCondor-CE is running well, decommission the GRAM software.