Weird CAS hangup on IOC

[Ralph Lange via Core-talk <core-talk at aps.anl.gov>]

Dear Core-talkers,

We have been seeing an IOC lately that occasionally seems to boot fine, does not print the usual "cas warning: Configured TCP port was unavailable. [...]" messages for not being the first one on the host, but then emits a

CAS: Listen error: Address already in use
Thread CAS-TCP (0x3337a20) suspended

and becomes CA unresponsive.

We recently changed our IOC startup to be systemd controlled and are starting all IOCs in parallel.

Question: Is there a vulnerability for a race condition where two IOCs are under the impression of being able to use the original CA port, but one of them eventually fails to listen()?

Cheers,
~Ralph