Experimental Physics and
Industrial Control System

On Jul 26, 2021, at 11:27 AM, Yendell, Gary (DLSLtd,RAL,LSCI) <gary.yendell at diamond.ac.uk> wrote:

I will look into that. I also tried running caSnooper:

$ caSnooper -t60 -p10 -c5

Jul 26 15:26:18:

There were 15078 requests to check for PV existence for 1960 different PVs.

  Max(Hz):   5.58

  Mean(Hz):  0.13

  StDev(Hz): 0.36

I have found many instances of a db expansion where the macros are not substituted correctly, so there are multiple records requesting the PV " CP" (and maybe "CP" - although I can't find those, so maybe it is just the output formatting)

e.g.

record(longout, "BL07I-EA-DET-10:OVER:1:PositionXLink")

{

    field(DOL,  " CP MS")

    field(OMSL, "closed_loop")

    field(OUT, "BL07I-EA-DET-10:OVER:1:PositionX PP")

    info(autosaveFields, "DOL")

}

Is it possible these requests are putting significant extra load on the IOCs?

It is possible, the best way to find out may to clean up the subnet if you can. If you can’t reboot the IOCs that are making the requests you could use caput to change the link field to a number or an empty string which will stop them running CA searches at least until they do next reboot (they will never connect to the current names, so you won’t be doing any harm to those IOCs anyway).

HTH,

- Andrew