Well its not really a race but I thought it would be interested to see how the rates to and from the Tier2 with
RAL.
So the clear winner is ( and probably
always going to be)
RALPPD. This should seem obvious since they are co-located so various factors (small
rtt, large bandwidth link for examples;) which would lead to a high rates. This lead to the rate plot as shown below:
Here you can see the rate has got to over 250MB/s
A close second I thought was going to be Glasgow, (they have a longer
rtt and lower bandwidth pipe so you would expect them to fair worse) :
This shows that they have got to 140MB/s
Sometimes it is unfair to compare these numbers since the number of concurrent transfers on the
FTS channels varies,. Glasgow actually have more concurrent transfers ( ~140MB/s with 42 concurrent transfers compare to ~250MB/s with
fewer concurrent transfers.) It is because Glasgow had the most
concurrent transfers that I thought it would have the highest rates:
But the peak rates I see for the sites appears to be the following (in the last month at least). If a site thinks they have seen better rates then comment on this Post!!!
(
rtt time between
SEs is shown in brackets after each record. Well its actually the
rtt to the closest router that
traceroute can resolve.)
RALPP 250 MB/s ( .2ms)
Imperial 250 MB/s (5.0ms)
Manchester 200MB/s (8.0ms)
Glasgow 140Mb/s (10.9ms)
Lancaster 100MB/s (6.4ms)
QMUL 100MB/s (5.7ms)
Birmingham 90MB/s (8.8ms)
Brunel 90MB/s (6.4ms)
Oxford 90MB/s (8.9ms)
Sheffiled 80Mb/s (9.1ms)
Liverpool 75MB/s (9.3ms)
RHUL 40MB/s (8.2ms)
Cambridge 30MB/s (10.3ms)
ECDF 20MB/s (12.9ms)
Bristol 17MB/s (4.0ms)
UCL 15MB/s (7.3ms)
Durham 12 MB/s (14.8ms)
For some sites the limiting factor seems to be the link (
ie transfers are running at line speed.) For other sites the limiting factor is the number of concurrent transfers currently set in
FTS. Some thing to tweak further....( Something really
interesting is that the top two sites are the only
dCache we have, but this could
just be coincidence since they are also the shortest and close to second shortest
rtt times of any site.
ATLAS have also started their sonar T2-T2 mesh of testing inter cloud T2 transfers. this made
me think of
the work I had done (bu
t not reported) about work I had done in looking in splitting STAR-T2 channels at
RAL into a slow
medium and fast channels. the rough split is western
European sites in fast channel, north
America in the
medium channel and south
America/
Asia-pacific in slow channel ( going from
rtt time) . This would be an initial split and
then some tweaking if
some sites were slower than their
rtt would suggest.
Interesting to see if ATLAS list of slow transfers
for UK sites match mine.
my list of slow sites would be:
Australia-ATLAS |
| BEIJING-LCG2 |
| CBPF |
| EELA-UTFSM |
| LCG_KNU |
| MA-01-CNRST |
| NCP-LCG2 |
| SDU-LCG2 |
| TOKYO-LCG2 |
| UNIANDES |
| TW-FTT |
| TR-10-ULAKBIM |
| INDIACMS-TIFR |
Medium sites ( North America)would be:
| Canadian |
| CA-ALBERTA-WESTGRID-T2 |
| CA-SCINET-T2 |
| CA-VICTORIA-WESTGRID-T2 |
| SFU-LCG2 |
| VICTORIA-LCG2 |
|
| American |
| UST3 |
| BUATLAS |
| UMICH |
| IUT |
| UTA |
| OU |
| UIUC |
| UCTP |
| STU |
| UCT2 |
| SMU |
| AGLT2 |
| WIS |
| UMFS |
| SWT2UTA |
| SWT2CPN |
Plus I am working with Glasgow to
see how much of their 6
Gbps can be used; but more on that in my next post.
What this calendar does not take into account are early datasets and defunct reprocessing datasets which have been deleted. I would love know what makes October 3rd and June 9th so popular??? Of course some of my children are alot bigger in terms of size and files ( and importance) which is lost in this plot.
