Sunday, June 03, 2007

Transfer Tests

Continuing with transfer tests between RAL-T2 and Glasgow over the weekend to investigate the effect of the Streams setting within glite-transfer-channel-set. Turns out it's not a very clear effect - negligible at best. As Greig has already noted that -T 1 is best for dcache, I propose we leave them at that.

However, totalling up the traffic for the weekend, I've moved 6.3 TB since friday afternoon (41h) which gives us a sustained average bandwith of 343Mb/s

But... Thats only 6.3 out of a requested 7.5. Only 7/15 transfers completed sucessfully with all 500 files being transferred. The others copped out with:

(mostly) FTS Reason: Failed on SRM get: Failed To Get SURL. Error in srm__get: service timeout.
(some) FTS Reason: Failed on SRM get: SRM getRequestStatus timed out on get
(twice) FTS Reason: Failed on SRM put: Failed SRM put on httpg:// ; id=... call. Error is File exists

So, considering I was transferring the same 50 seed files, thats quite alot of crapness on behalf of the dCache source. Not sure what caused the two false "file exists" failures. I severely doubt that more than 10% failure rate is acceptable to the experiments.

I'll present the full findings (once I've plotted them) at the GDB Meeting on Tuesday

Worth noting that Pauls MonAMI data was v useful in keeping an eye on the dteam specific data pool usage, together with the health of the DPM service at Glasgow.

No comments: