16 December 2007

Anyone for some dCache monitoring?

The above plots come from some new dCache monitoring that I have set up to study the behaviour of the Edinburgh production storage (srm.epcc.ed.ac.uk). This uses Brian Bockleman's GraphTool and some associated scripts to query the dCache billing database. You can find the full set of plots here (I know, it's a strange hostname for a monitoring, but it's all that was available):


GraphTool is written in python and uses matplotlib to generate the plots. Cherrypy is used for the web interface. The monitoring can't just be installed as an rpm: you need to have PostGreSQL 8.2 available; create a new view in the billing database; set up Apache mod_rewrite; ensure you have the correct compilers installed..., but these steps shouldn't be a problem for anyone.

I think you will agree that the monitoring presents some really useful views of what the dCache is actually doing. It's still a work in progress, but let me know when you want to set it up and I should be able to help.

It should be possible to do something similar for DPM in the coming weeks.


Brian Bockelman said...

Hey! Looks like you figured out how to replace the background image too.

Looks nice.

Greig A Cowan said...

Yep, thanks for your installation tips! Now I just need to try and convince all other sites to use it.

Brian Bockelman said...

The OSG Storage Activities folks are working on deploying a Gratia probe which would mine the billing DB and send the results to a central DB.

The probe currently needs a bit more packaging work and some correctness verification, but once I'm happy with its quality, I'll be writing another billing graphs interface for the central DB.

That would mean sites don't need to install the full list of dependencies - just install the Gratia probe RPM, and you get the site info from the central statistics.

OSG will have its centralized Gratia repository but it doesn't appear to be too hard to run a repo for, say, GridPP.

In addition, it would mean one only has to write a Gratia probe for DPM to add a DPM site to the monitoring, instead of another web interface.

This sort of stuff should unfold over the next 2 months.

Greig A Cowan said...

The Gratia monitoring sounds interesting. I could perhaps contribute something for DPM. Do you have any docs on writing Gratia probes and about the system in general?