RE: IOC PVs intermittently flicker between values and LINK INVALID

[Mark Rivers via Tech-talk <tech-talk@aps.anl.gov>]

Have you run diagnostics like “top” to look at the CPU and memory usage of the IOC process, as well as the system as a whole?  It sounds like it could be a memory leak or CPU saturation issue?

 

Mark

 

 

From: Tech-talk <tech-talk-bounces@aps.anl.gov> On Behalf Of Tran, Phi Dung via Tech-talk
Sent: Thursday, August 21, 2025 11:36 AM
To: tech-talk@aps.anl.gov
Subject: IOC PVs intermittently flicker between values and LINK INVALID

 

Hello Tech-Talk,

I’m running into an issue where one of my IOCs behaves normally after a reboot, but after several days of uptime all PVs begin to flicker — they alternate between their correct values and LINK INVALID.

Some details:

• Rebooting the IOC clears the issue temporarily, but the flickering returns after a few days.

• This affects all PVs in the IOC, not just specific ones.

• I’ve observed the problem using camonitor as well as in client GUIs (CS-Studio).

Please advise thank you,

Alex