The Beauties of BLAH

Francesco Prelz (

INFN - Sezione di Milano

Condor Week 2007, Madison, May 2, 2007


Premise, by way of introduction: INFN has been collaborating with the Condor group for more than 10 years, and this long history, plus the long history of Condor, were the basis for trying to address together some of the big-G challenges: One of the few things we know for sure is that long-term maintainability will be needed.

Why BLAH ? (1)

Why BLAH ? (2)

Current BLAH operation.

Main pros and cons.


Practical and workable abstraction to map the job lifecycle onto a different system.
Still a reasonably simple component with little dependencies ('new' Classads and Globus GSI for proxy renewal - batch system are interfaced to via CLI).
Hard to resist pressure to add more functionality to this supposedly thin layer (various schemes for proxy renewal, information collection for accounting purposes, etc.)
Porting to new batch systems could be simpler. Current Bourne shell interface scripts are already pretty stratified, and would benefit from a cleanup.
Needs some tracking with new versions of batch systems to synchronize with changes in client functionality and log formats. No change needed here in the past 3 years - we now have an official liaison with Platform to handle 'surprises'.

Condor+BLAH in the 'gLite-CE'.