gridengine.info

In my mind, one of the most under-appreciated and under-used features of the Grid Engine 6 series is the ability of the ”qstat” program to output terse or very detailed status information in XML form. For those of us used to parsing human-readable qstat output using perl regular expressions and other painful methods this is very welcome news. Grid Engine apparently also communicates internally now using XML-formatted messages but lets save that topic for a future post.

I wrote about early efforts at trying to do something useful and usable with Grid Engine XML for a Bio-IT World magazine column. A snippet of the article is reproduced here:

Where raw Grid Engine XML status data are concerned, XPATH is the technology that allows one to cut through the large volume of data to make targeted queries. Queries such as “Give me information about all pending grid jobs” would be represented as an XPATH search string: “//job_list[@state=‘pending’]”.

The use of XPATH addresses one problem: “How do I wade through lots of XML and pick out the bits that I’m actually interested in?” This is only a partial solution, as one still has to do something interesting (or at least visually pleasing) with the selected XML data. This is where another W3C recommendation comes into play: XSLT 1.0.

The full article can be read online here: http://www.bio-itworld.com/columns/inside-the-box/insidethebox0705

xml-qstat

One of my personal development projects lives at http://xml-qstat.bioteam.net. It represents an attempt to build rich Grid Engine monitoring tools that make use of XML status information. The software is released under a creative commons license and written in Perl. The actual XML handling is done by libxml2 and libxslt libraries from www.xmlsoft.org.