August 18, 2006

Attending

• Blackwell (SFA)
• Hagewood (Nevoa)
• Beck, Moore (UTK)
• Brown, de Ledesma, Sheldon, Tackett (VU)
• Swany (UDel/CERN)

Current Agenda

Application Communities

• Update on work with Electron Microscopy (Micah/Chris)
• News from CERN (Martin)?

Deployment and Operations

• Visit to Fermi (Bobby)
• Deployment to ORNL (Bobby)
• Status of AMPATH testing (Surya/Hunter)
  • Progress on Brazilian depot deployment at well connected locations
  • Plans for future tests

News from the AMPATH Runs:

I am in Seattle, so am sending my side of things by email. If you do need further clarifications, you can call me on my cell (6152758519).

1. So far we have had two machines that have been available to us at Rio. I have used both lors and lstore to do test runs. Since the c lors library is about 1.5 times faster than the java lors library i have been using the c library for the test runs.

2. The network set up at Rio is something i do not quite understand. Initially i was able to get about 110 Mbits/sec per box thus filling about 25 % of the pipe. Each machine was running anywhere between 6-8 clinets transfering a 250 MB file with 20 MBytes block sizes. The TCP window size on the depots were configured to 256MBytes where as on the clients were set to 128 MBytes. The weirdness lies in the fact that we have seen occasional peaks of about350 MBits/sec with the two machines. Infact this week i have seen sustained around 160 MBits/sec using just one client. This result was coincidental with a infrastructure failure at the rio end. At the time we saw this burst only the machine i was using was running with a very limited number of other things going on on their campus network.This leads to me towards a thought: their must be something going on during other times that is limiting the performance of the individual machines. We are definitely sharing these boxes so its hard to identify whether it is a network issue or something else. Iperfs have though established that we do see about 600 Mbits/sec so we are no where close to that figure.

3. In any case right now they have a major infrastructure breakdown (no airconditioning) so we hae only one box.

4, Ofcourse no root access to the box also means that it takes time to tweak anything on that side.

5. Thanks to takeo we have a box. But i have been seeing only 17Mbits/sec(yes it is bits and not bytes). There is something that needs to be adjusted. I have asked Takeo to change the TCP window size to 128 MBytes. Haven't heard back.

6. Plans: Rio has promised 6 machines. And once i get sau paulo i will keep running tests and update this group. My gut feeling is that its is a set up issue on that side. There is no question regarding whether we can saturate a 1 gig pipe or not.

Again call me if you need some more details.

Thanks

Surya

Technology: Hardware, Software

• lodn_cp (Micah)

Events, Education, Outreach

• Upcoming OSG meeting (Paul, Surya)
• SC06?
  • Status of Ultralight plans (Alan)
• Plans for Internet2 Side meeting (Terry, Micah)