wiki:developers-meeting-20090602
Last modified 12 years ago Last modified on 06/02/09 18:29:24

dCache Tier I meeting May 5, 2009

Present

dCache.org(Paul), IN2P3(), Sara(Ono), Triumf(Simon), BNL(), NDGF(Gerd), PIC(Gerard), GridKa(Doris/Silke?), Fermi(), CERN()

Agenda

  • Site reports,
  • Issues tuning SRM,
  • Trash feature in dCache,
  • FTS and GridFTP-2,
  • DTNM.

Site reports

GridKa

Nothing to report.

FZK is not taking part in STEP due to an issue with their tape back-end. This is not dCache related. The issue may be resolved by the end of the week and FZK's participation in STEP may be updated.

PIC

Everything is fine.

PIC had an issue with the gsidcap door in v1.9.2-5; upgrading to v1.9.2-7 for the gsidcap door fixed this issue. All other components are running v1.9.2-5, including PnfsManager. So far, there's been no sign of the performance issue with v1.9.2-5.

NDGF

No issues to report.

Last week NDGF upgrade to FTS v2.1. Everything is still working.

Triumf

Still having some problems with the SRM. Have been adjusting some of the parameters, but it is unclear what to change. For example, what does XXX mean? How does this affect the SRM?

Gerd: this affects the internal assignment of tasks to thread-pool. However, almost everything in SRM is done asynchonously. This meaning that limiting certain values (such as XXX) doesn't affect the SRM much. For srmPut and srmGet, altering this value doesn't make much difference.

Simon reported that he doesn't changes the parameters in SRM much partly due to a lack of documentation.

As a general question: What are people's usage for SRM parameters: do people take the default values or customise the values? What do the dCache team recommend?

[discussion as a later agenda item.]

SARA

We are running without problems.

Sara are now running v1.9.0-10. This seems to be rock solid: dCache was sustaining a bandwidth of 1GB/s for a day without any issues: the bigger issue was with network congestion.

Sara is planning on staying with v1.9.0-10 for at least the medium-term. It will be certainly after STEP and (very likely) after summer before Sara will consider upgrading dCache.

SRM

Continuing from earlier discussion: have sites updated their SRM configuration or do they use the default values?

FZK: have changed them significantly.

Gerard: it could be useful to upload dCache config. files to a common website. This was an agreement from the Karlsruhe dCache workshop. For today, perhaps we could send the files around via email.

Doris: upload to a common area is a good idea.

Gerd: Is dCache trac publicly writeable?

Paul: don't know, but I think it's not.

Could we use subversion?

(no real clear answer)

Gerd: how about publishing the configuration files on a public website?

Sites could ensure that they provide up-to-date information and only the information that they're happy with making public.

Question to all participiants: are people happy to do this?

  • Triumph: OK.
  • FZK: need to discuss this, but shouldn't be a problem.
  • NDGF: need to discuss, but should be OK.
  • PIC: Yes.

Consensus view was that sites should place a copy of their dCache configuration on a publicly accessible website and to send an email to dCache SRM/Tier-1 support mailing list with the URL(s).

The trash feature PNFS

A question from Gerard: what is the status of the trash feature in PNFS?

Gerd: support has been in dCache since v1.9.0.

We're waiting on a new version of PNFS.

FTS and GridFTP 2?

Gerd asked which sites have upgraded to FTS v2.1 and have enabled dCache's GridFTP v2 support for passive FTP?

PIC

We have deployed FTS v2.1 and enabled GridFTP v2 support.

There have been several issues, so the decision was to disable it. The issues were mainly when talking to Tier-2 sites. These haven't been fully investigated so we don't know the actual cause.

The plan is now to deploy a single test-instance of dCache with GridFTP-2 support. We will then validate each Tier-2 centre in turn.

Gerd suggested that a likely cause was Tier-2 centres that have enabled passive transfers to pool without realising the requirements.

Triumf

GridFTP v2 was enabled last week: both within FTS and dCache. Everything is OK so far.

There has been a big difference transfers: seeing ratios of 1:3 (sometimes to 1:2) transfers now using GridFTP v2.

DTNM

Proposed: Tuesday 9 June 16:15 CEST

http://timeanddate.com/worldclock/fixedtime.html?year=2009&month=6&day=9&hour=14&min=15&sec=0