RE: same PV on multiple IOC's - side effect

["Jeff Hill" <johill@lanl.gov>]

> Before I try and for those of us who use non-standard an dmultiple
> ports, can I simply set
> EPICS_CA_ADDR_LIST="<broadcast>:<port#1> <broadcast>:<port#2>"
> ?

Yes, that configuration option is supported. You might also decide to set
EPICS_CA_AUTO_ADDR_LIST=NO.

It's a bit more complicated when more than one port is in use to make
certain that the client sees all of the server beacons because the CA
repeater configuration is more complex.

What is the downside of the client not seeing all of the server beacons?
First, a long lifespan client might be slower connecting to a newly
introduced server(clients search a bit faster for awhile shortly after a new
beacon is seen). Second, the client might use a small amount of additional
network bandwidth periodically checking idle TCP circuits for responsiveness
(if the beacon isn't seen the client periodically verifies the idle tcp
circuit with a roundtrip message).

Jeff

> -----Original Message-----
> From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-
> bounces@aps.anl.gov] On Behalf Of Emmanuel Mayssat
> Sent: Thursday, September 27, 2007 10:26 AM
> To: Andrew Johnson
> Cc: TechTalk EPICS
> Subject: Re: same PV on multiple IOC's - side effect
> 
> Andrew,
> 
> On Thu, 2007-09-27 at 10:48 -0500, Andrew Johnson wrote:
> > To tell the client library to only search the control network, set
> the
> > following two environment variables
> >    EPICS_CA_AUTO_ADDR_LIST=NO
> >    EPICS_CA_ADDR_LIST=<broadcast address of control subnet>
> > The broadcast address is shown on the output from /sbin/ifconfig -a
> and
> > is probably 172.16.4.255 but it may have different numbers in the 3rd
> or
> > 4th positions.
> 
> Before I try and for those of us who use non-standard an dmultiple
> ports, can I simply set
> EPICS_CA_ADDR_LIST="<broadcast>:<port#1> <broadcast>:<port#2>"
> ?
> 
> --
> Emmanuel