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Feature #23689

Feature #23741: Improvements and clarifications for using XRootD

Opening xrootd files

Added by Herbert Greenlee 11 months ago. Updated 11 months ago.

Status:
Under Discussion
Priority:
Normal
Assignee:
-
Target version:
-
Start date:
12/03/2019
Due date:
% Done:

0%

Estimated time:
Scope:
Internal
Experiment:
MicroBooNE
Duration:

Description

Is it possible to make RootInput more robust against xrootd failures when opening xrootd files? One failure mode that I think happens is that if you try to open an xrootd file for streaming, and the root file is not staged, the time to stage the file may be longer than the xrootd timeout. There may be other kinds of glitchy xrootd failures. Here are some possible feature enhancements.

1. Check the dCache locality of a root file before trying to open using xrootd.
2. More robust retry machanisms.

History

#1 Updated by Kyle Knoepfel 11 months ago

  • Status changed from New to Under Discussion

Herb, please look at the comments in issue #21638. As ROOT is the client of XRootD in this particular case, XRootD behavior is controlled based on ROOT's use of XRootD. Hopefully there is enough flexibility described in issue #21638 to mitigate the issues you've encountered.

Also, note that roughly 1 year ago, some errors were fixed with art's handling of XRootD failures (see issue #21289). Unfortunately, there are some errors (e.g. authentication errors) where the timeout window is not configurable.

That said, I know that this can be a frustrating issue, so I will schedule a meeting in the near future with you and others to help go through the desired features/bug fixes to make the art's ROOT file-handling easier to use.

#2 Updated by Kyle Knoepfel 11 months ago

  • Scope deleted (Internal)
  • Parent task set to #23741
  • Project changed from art to art_root_io


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