Experimental Physics and
Industrial Control System

[email protected] (Jeff Hill) · Wed, 21 Jul 1999 18:52:49 -0600

All,

Last week during testing I found a bug in the channel 
access client library which, while it should occur under 
rare circumstances, is significant because it could result 
in the failure of client side programs. If the problem 
occurs in client programs running in the IOC experimental
evidence indicates that under heavy network communication
load network communication may stall or permanently fail. 
I introduced the bug into R3.12 in August of 1995.

Symptoms on a workstation: 
o client programs stall or hang when the workstation is
experiencing heavy network communication load

Symptoms on an IOC:
o dbCaLink or sequencer task in IOC is temporarily
or permanently using all available CPU at its priority
level.
o network communication to the IOC stalls or possibly
permanently fails under heavy network communication load

A patch for R3.13 will be available soon (I have committed 
a fix to the R3.13.1 branch at APS). My apologies for any 
inconvenience that this has caused.

Jeff
______________________________________________________
Jeffrey O. Hill           Internet     [email protected]
LANL MS H820              Voice        505 665 1831
Los Alamos NM 87545 USA   FAX          505 665 5107

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System