sheila.dwyer@LIGO.ORG - posted 22:07, Friday 10 July 2015 - last comment - 18:32, Sunday 12 July 2015(19566)
EPICs freezing
We've noticed two more examples of epics channels freezing for a few seconds. Yesterday (July 9 16:25:09 UTC) and tonight (0:22:49 UTC July 11)
I have opened an FRS on this issue (#3279) which contains details of my investigation. I have seen two extended CA freeze-ups of LSC over the past two days (11 and 14 seconds in duration) with an apparent increase in CPU load on h1lsc0 at the time. The DAQ data does not show any drop-out, this only impacts CA access to LSC data. This is an inconvenience for MEDM and StripTool, but has potentially more serious implications for Guardian. Investigation is continuing. With only one large event per day it unfortunately takes some time to gather data. I'm also trying to reproduce the issue on the DTS.
https://services.ligo-la.caltech.edu/FRS/show_bug.cgi?id=3279
Just to build statistics, we observed these dropouts as well: