Sniffing out the VOs

Fri 15th February 2013

Today the GridPP team at the University of Liverpool release the latest version of their VomsSnooper tools. The toolkit tracks changes and manages user’s software making it easier for grid site administrator to keep their software up to date for every person that uses their machines.

All researchers working on the grid will have particular software requirements and the systems administrators have to keep on top of these. One way the grid simplifies this is by grouing people working on similar experiments or science together into Virtual Organisations (VO), This helps simplify communication, requirement requests and software announcements, however it’s not a cure-all solution.

When you are looking after a computer cluster with a massive number of users and applications, automation is the name of the game. If a sys admin had to manually check every user, every data source and every application running on their machines they’d need more than 24 hours in a day. Unsurprisingly a lot of these processes are automated but when it comes to VO software it’s not the updating that’s a problem, it’s knowing that it needs to be updated.

“The tools we use to configure the software at our sites is pretty good at keeping everything up to date” says Stephen Jones at the University of Liverpool “but it first has to know an update is available. This all hinges on the correct information being available to sys admins and them doing a manual update”. For GridPP sites this information is on a wiki page, a page which was updated by hand, adding extra unreliability.

dog nose by Mark Watson
dog nose by Mark Watson

However Stephen realised that the EGI Operations Portal could hold the key. The portal is a large database containing a wide variety of information about every VO on the grid, including what users are part of it, what resources they have access to and what software it uses. “All the information we need is there” explains Stephen “but it needs to be trawled through, converted manually and the sys admin has to actually remember to do it regularly. This makes the task labour intensive and unreliable. I knew we could do better than that”.

When Stephen started to investigate he discovered that the information was available in a flexible format that can be used to present data so both machines and humans can understand it. “This was important” says Stephen “if a machine can read it, then it can be automated”.

VomsSnooper Logo

By June last year Stephen had developed the VomsSnooper toolkit so it could keep the wiki page up to date, check that a sites software configuration matched those in the Operations Portal and if it did not create the correct new files for the sys admin. “I was very happy with my progress” says Stephen “but once the application could ‘read’ the information on the Portal I realised I could do a lot more so started adding functionality and thinking of different use cases. Now VomsSnooper can actually perform 10 different tasks“.

This latest release includes updates to extend VomsSnooper to make introducing new VOs easier and simplifying a roll back if any problems happen with newly installed software. “As new, small VOs become common, we need a decent way to bring them into the grid quickly and with the minimum fuss. ” says Stephen “I hope VomsSnooper can make this a reality and would like to more sites adopting the toolkit”. Stephen will be presenting his work at the EGI Community forum, which is in Manchester from April 8th to 12th.

More information on deploying and using the VomsSnooper tools is available on the wiki page http://www.gridpp.ac.uk/wiki/VomsSnooper_Tools.


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