Corporate Makeover

Thanks to Neasan O'Neill, the Planet GridPP page now has a shiny new stylesheet to match the main GridPP site.

planet.gridpp.ac.uk

I'd been trialling planet, the RSS aggregator for a few months now, and I'm fairly pleased with it. So much so that it's now official :-)

http://planet.gridpp.ac.uk should now show you, in a single place all the various Tier-2, operations and storage blogs. If there are any others that people want adding, drop me a note.

srm-advisory-delete

OK, I'll admit I occasionally rant about some things I consider "bad", but I'm afraid deleting files from grid storage is just Painful.

to delete 490 (I nuked the first ten within the inner $i loop as a test of xargs) files I ended up with this nasty nasty hack:

for j in `seq -w 2 49 ` ; do for i in 0 1 2 3 4 5 6 7 8 9 ; do echo -n "srm://$DPM_HOST:8443/dpm/gla.scotgrid.ac.uk/home/dteam/rt2-gla-5-1/tfr000-file00$j$i " ; done ; done | xargs srm-advisory-delete

I mean, even altering for a `seq -w 20 499` single loop, just, well, is Bad and Wrong[*]

/rant

Mind you, it worked, as demonstrated by Paul's MonAMI plot of dteam storage use:

iperf between Gla-Bristol

In preparation for some serious testing of Bristol's StoRM implementation, Jon and I worked together to run some iperf tests so we know what our target is for FTS tests. Plot below - looks like we've got a 500Mb/s maximum.

Wouldn't it be cool if....

Someone could hack something like flickrvision into the realtime monitor. hmmmm.

Transfer Channel wiredness

As I still haven't completed this quarters round of transfer tests I decided to set up all the scripts and prereqs for doing each T2. Ran my little perl script to get the current (pre-tuned) values for the transfer channels and noticed that they were all set to 5. Nope, my script hadn't broken (more than originally designed anyway) - it looks like someone changed 'em. Why?

Site           From RAL  Star    To RAL
UKI-NORTHGRID-SHEF-HEP  5       5       5
UKI-LT2-IC-LESC         5       5       5
UKI-SOUTHGRID-BHAM-HEP  5       5       5
UKI-SOUTHGRID-OX-HEP    5       5       5
UKI-LT2-IC-HEP          5       5       5
UKI-SOUTHGRID-CAM-HEP   5       5       5
UKI-LT2-UCL-HEP         5       5       5
SCOTGRID-EDINBURGH      5       5       5
UKI-LT2-UCL-CENTRAL     5       5       5
UKI-NORTHGRID-MAN-HEP   5       5       5
UKI-SCOTGRID-GLASGOW    5       5       5
UKI-NORTHGRID-LANCS-HEP 5       5       5
UKI-SOUTHGRID-BRIS-HEP  5       5       5
UKI-LT2-BRUNEL          5       5       5
UKI-SCOTGRID-DURHAM     5       5       5
UKI-SOUTHGRID-RALPP     5       5       5
UKI-LT2-RHUL            5       5       5
UKI-LT2-QMUL            5       5       5
UKI-NORTHGRID-LIV-HEP   5       5       5

You're only supposed to blow the bloody doors off!

Apart from the Spring HEPiX 2007 meeting last week (which was excellent BTW - I'll do a proper writeup soon) I have been pushing on with Transfer tests. Rather than risk stressing the RAL CASTOR service too much while we work on improving the individual T2 sites, Chris Brew (RAL T2) was v helpful and we've been using their dCache pool (lots of beefy disk servers and some spare capacity) to push out to the T2 sites.

I have knocked up a simple "template" based script for performing the tests now so that I can run serveral sites serially automatically. This means I can set up a screen session to do all sites within a T2 then come back later and look at logs. What we've discovered is that we can set the glite-transfer-cheannel settings much more aggressively than we have been.

Some Examples
* GLA to RALT2 1TB transferred in 3:09:29, Bandwidth = 703.63 Mb/s
* RALT2 to GLA 618G transferred in 2:11:48, Bandwidth = 625.13 Mb/s

As CMS were also doing tests from the T1, we managed to saturate the 1G connection at Imperial College. Whoops. However we also set a new record for HEP Throughput at that site (previous record was ~800Gb/s overnight)