23 June 2011

A Little or a lot. How many transfers should an SRM be handling??

The new atlas dashboard (version 2.0) now allows for better analysis of data flows. For the RAL T1 ATLAS endpoint of Castor, the breakdown for number of successful transfers from across the world both to and from RAL is as follows.
Firstly into RAL (over the last four weeks:)
TOTAL-
1966315

CA+
12191

CERN+
140494

DE+
27543

ES+
15085

FR+
31555

IT+
15514

ND+
10891

NL+
23515

TW+
6505

UK+
1636099

US+
46923

Unsurpisingly; the majority of transfers are from with the UK; (due to the UK Tier 2s. ) However , 16.8% of transfers in are from outside the UK. (3% or 59k are transfers are internal RAL-RAL transfers.)

The number of transfers for when RAL is a source are:
TOTAL-
872941

CA+
39604

CERN+
150286

DE+
66500

ES+
17848

FR+
78635

IT+
57309

ND+
19585

NL+
22602

TW+
37437

UK+
303770

US+
79365


( NB. There is a small amount of double counting as the 59299 RAL-RAL transfers appear in both sets of figures in the "UK" values.) average filesize was 287 MB and took 80.43 seconds to copy.
100k per day at RAL for ATLAS.
320k per day at BNL for ATLAS.
140k per day at FZK for ATLAS.
150k per day IN2P3 for ATLAS.

Now the SRM also has to handle files being written into it from the WNs at a site. The number of completed jobs for a selection of T1s is:
18k per day at RAL for ATLAS.
50k per day at BNL for ATLAS.
27k per day at FZK for ATLAS.
15k per day IN2p3 for ATLAS.

Now each job on average produces two output files; meaning that for RAL, ~35/135 of its SRM transfers (~1/4) come form its worker nodes.

UK T2s do approximately 80k transfers per day for ATLAS ( and complete ~50k jobs per day).

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