[Halld-online] Hall-D Online Meeting Minutes

[David Lawrence]

Hi All,

  Here are the minutes from today’s Hall-D Online meeting:

https://halldweb.jlab.org/wiki/index.php/OWG_Meeting_5-May-2016

Regard,
-David

Minutes[edit]

Attendees: David L., Sergey F., Paul L., Hovanes E., Curtis M., Sean D., Beni Z., Simon T., Eugene C.
RAID Disk Upgrade[edit]

David summarized some points of a conversation he had with Chip and Sandy the day before
With our current 800MB/s data rate, we no longer have a 72 hr buffer of disk space
Our existing servers may be coming to the end of their warranty period
Currently, we always keep some data on RAID disks and so only tend to free up 50TB when a disk is cleared out
This makes our effective current buffer ~100TB = 34 hrs of buffer
Existing drives in gluonraid1 and gluonraid2 are 3TB. Replacing them with 6TB drives would approach cost of new server with new drives
New server similar to our existing one but with 6TB drives would be an estimated $14k
Computer Center has started using 3rd party company service contracts for hardware to replace expiring warranties
Our existing raid servers will hit 3 years this Sept. and we should look at setting up such a service contract from ~$100/month
Paul is looking into identifying RAM for us to purchase to increase from 32GB to 64GB in gluonraid1 and gluonraid2
Proposal for 3rd RAID as small buffer was presented
Addresses issue of stopping and restarting DAQ so ER can be run on different node when switching disks
Can limit access to disk from other users while DAQ is running, reducing potential conflicts
We decided to explore such a scenario using the existing 2 RAIDs and the 3rd RAID described above.
Announcements[edit]

We will change the meeting time to 2pm, but keep it on Wednesdays
Hovanes noted that this can interfere with the Wed. afternoon Accelerator meeting
We decided to keep it on Wed. since we don't usually have Online Meetings during the run anyway due to daily RC meetings.
Paul will likely do the gluon01 downgrade next week. We told him there was no time pressure since people will be occupied with the Collaboration Meeting/Workshop
Collaboration Meeting Agenda[edit]

Agenda is now frozen. Naomi will speak for precisely 10 minutes. No more, no less.
Compiler Upgrade[edit]

The offline group will officially require a C++11 compliant compiler (e.g. gcc 4.9.2) starting June 1st.
The hdops account uses sim-recon for monitoring histograms and hdview2 so we will need to support this change
Hovanes argued that making the default compiler something other than the current 4.4.7 would require significant effort to not just recompile all of the controls software, but to test it all and ensure it still works correctly
Controls group has full list of high priority tasks prior to the Fall run with no significant manpower available for this testing
If the default compiler for hdops is not changed to gcc 4.9.2, then programs compiled with it will need to be outfitted with launch scripts to setup the proper environment before the program is run
No consensus was reached. Further debate was deferred to a later date
DAQ[edit]

Sergey had to leave so no DAQ report
L3 Status[edit]

New low-level EVIO parsing code is still under development, but seems to be working at roughly 3x the speed of old parser
Lower level reconstructed objects (e.g. DTrackCandidate) are produced with the same parameters, but higher level ones (e.g. DTrackTimeBased) have some discrepancies
Current best estimate is L3 will be able to process 1kHz per node (or equivalent thereof)
New nodes (to be purchased this year) should be about 2x as fast. Thus, current estimate is we will need 50 of those types of nodes for L3
Will be purchasing 8 new nodes as part of CC annual procurement
ROL Status (SYNC events)[edit]

Alex S. not at meeting so nothing was reported

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