Friday, November 06, 2009

Arc, and the installation

We've been fiddling with the NorduGrid Arc middleware a bit. Not just out of random curiosity, but more trying to get a handle on the workloads that it suits better than gLite, and vice versa. It does a number of things differently, and by running an Arc CE in parallel with an lcg-CE and CREAM, we can do some solid comparisons. Oh, and the name of the middleware is also much more amenable to puns, so expect a few groaners too.

So, consider this the first in a series. During this process, we expect to end up with a set of notes on how to install and run an Arc setup, for people already familiar with gLite.

Firstly, install. We took a blank SL5 box, added the nordugrid repo's, and then

yum groupinstall "ARC Server"
yum groupinstall "ARC Client"

Well, very nearly. There's one more thing needed, which is to add the EPEL dependancies (libVOMS is the key lib)

yum install yum-conf-epel

The next step is to configure it. That's all done in /etc/arc.conf, and is the subject for later posts.

There is a need for a filesystem shared between the CE and the worker nodes, so we fired up a spare disk server for NFS.

Startup is three systems, already configured in /etc/init.d : gridftp, grid-infosys and grid-manager.

Ta-da! A running Arc CE.

Ok, so there's a fair bit glossed over in the configuration step. Next time, I'll talk about how I configured it to work with our existing queues - and where the expectations for Arc differ from gLite.

1 comment:

Leif Nixon said...

I hope you will have a joyful ARC experience! Pool accounts are handled in a somewhat original fashion in ARC; in Swegrid we're instead using a small plugin script to accomplish the mapping.