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Meeting Info

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Access Code: 840-709-413
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Meeting ID: 840-709-413





  • Go over agenda items

Discussion items

10 minBringing new Board membersAll
  • Q: people from ORNL maybe interested; they can present the case why they don't use HDF5
  • M: we would like to have people with technical knowledge of HDF5
  • M: Have a discussion item with the current TAB if technical knowledge of HDF5 is necessary.
40 minTechnical discussion:SubfilingJohn M.

Goal of sub-filing will be reduce contention of parallel FS. Caller uses HDF5 parallel interface.

One of the approaches is to write things quickly to the disk, keep track of where things are, and reconstruct when reading back.

M: Groups of processes writing to an HDF5 file, there only serial access to the files. Applications should be aware how they need to operate. Is there any things HDF5 can done better? Almost everything is done.

2 phase I/O - both proposals aggregate data.

NERCS 10 is focusing more on workflows: creating a file that will be read in the next stage. Mark agreed that work-flow is important.

Keep in mind node local storage when designing sub-filing, also file per-processor.

Usually executables are write-only. When reading back, application is re-launched with the same # of ranks most often, but applications can run from other # of ranks.

Don't disregard file-per-process, but there will be no code changes if application writes file per 10 processes, etc. But this not a design goal.

M-to-N when M/=N

Suren: aggregation should be part of the design.

Suggestion: discussion of new technical ideas - slides for the last 10-15 minutes and then decide for more deep technical discussion.

Function of TAB to create "committees" that will look into technical discussions.

Ask TAB to look into reviews from Tutorial submissions well in advance of submission to SC.


Decision made

Have the meetings on the first Monday of the month at 11:30 am Central (the first 3 minutes of recording)