Experimental Physics and Industrial Control System

I have observed the same behaviour. In addition, I have observed that
it depends on the -no_cache option. I can't think of an a priori
reason why caching would affect monitors (apart from storing their
value, of course), but it goes beyond just the first monitor after
subscription.

With caching enabled:

  - first subscription yields just one monitor, as expected;
  - subscribing with event mask set to 'a' works as expected;
  - caput command returns the old value (which is understandable, if
    annoying).
  
With the -no_cache option:

  - first subscription yields two monitors;
  - subscribing with event mask set to 'a' results in no monitors when
    the record changes alarm status.
    
Log events behave as expected as long as the -archive option is
given. I hope these observations will help with tracking down the
issue.

Best,
Jure

On Friday, May 31, 2019 6:50:05 PM CEST William Layne via Tech-talk wrote:
> I ran two tests with two different PV types, ENUM and LONG. I saw the same
> behavior as before.
> 
> In each test I ran cainfo followed by a camonitor in two different
> terminals, one directed at the gateway and one at the direct network.
> 
> Cainfo for terminals directed at gateway we're using localhost:5064. The
> cainfo for terminals directed at direct network were using
> <broadcast>:<random port that ioc was using for tcp>.
> 
> Camonitor for terminals directed at the gateway saw duplicate values in
> camonitor. The terminals directed at the direct network did not.
> 
> 
> 
> 
> On Wed, May 29, 2019, 5:59 PM William Layne <[email protected]>
> 
> wrote:
> > I left out the other environment variables, but we have
> > EPICS_CA_AUTO_ADDR_LIST and do not see any exceptions or warnings for
> > duplicate IOCs. The logfile for the gateway does have one exception for
> > an unrelated PV (which I know is duplicated between two servers).
> > 
> > I can also confirm that I only see one update on the main network.
> > 
> > When I get in tomorrow, I will run cainfo and camonitor with main
> > network/localhost side by side.
> > 
> > On Wed, May 29, 2019, 5:51 PM Johnson, Andrew N. <[email protected]> wrote:
> >> I agree that setting EPICS_CA_AUTO_ADDR_LIST to NO may be important, but
> >> if that's the only issue it should only result in Duplicate PV warnings
> >> from camonitor, not in duplicated heartbeat monitor values on the
> >> connected
> >> channel.
> >> 
> >> What hostname does the "cainfo" program tell you the PV is found on, and
> >> have you been seeing any warnings about duplicate PVs found?
> >> 
> >> Is your Gateway generating any warnings about duplicate PVs? I suspect
> >> they'd go into a logfile but I forget exactly how that is configured.
> >> 
> >> Can you run camonitor connected to the main network and report whether
> >> you see the same duplicate heart-beat values? Repeat that with cainfo
> >> too...
> >> 
> >> - Andrew
> >> 
> >> 
> >> On 5/29/19 4:36 PM, Mooney, Tim M. via Tech-talk wrote:
> >> 
> >> You probably want to set EPICS_CA_AUTO_ADDR_LIST to "NO".  Setting
> >> EPICS_CA_ADDR list doesn't restrict attention to the named IP addresses,
> >> it
> >> just adds them to the list of addresses already found in the init
> >> process.
> >> 
> >> Tim Mooney ([email protected]) (630)252-5417
> >> Beamline Controls Group (www.aps.anl.gov)
> >> Advanced Photon Source, Argonne National Lab
> >> 
> >> ------------------------------
> >> *From:* [email protected] <[email protected]>
> >> <[email protected]> on behalf of William Layne via Tech-talk
> >> <[email protected]> <[email protected]>
> >> *Sent:* Wednesday, May 29, 2019 4:14 PM
> >> *To:* Jemian, Pete R.
> >> *Cc:* [email protected]
> >> *Subject:* Re: Receiving duplicate monitor values using CA PV Gateway
> >> 
> >> Forgot to CC tech talk. Oops.
> >> 
> >> Yes, we have a few interfaces. I guess it would help to give some info on
> >> that. We have it setup with client and gateway both on the same machine:
> >> 
> >> Client environment settings:
> >> EPICS_CA_ADDR_LIST=localhost; EPICS_CA_SERVER_PORT=5064;
> >> 
> >> Gateway settings:
> >> -cip <network broadcast>
> >> -sip localhost
> >> 
> >> IOC settings:
> >> EPICS_CA_ADDR_LIST=<network broadcast>; EPICS_CA_SERVER_PORT=5064;
> >> 
> >> 
> >> [Client] <--> ||localhost|| <--> [Gateway] <--> ||network broadcast||
> >> <--> [IOC]
> >> 
> >> On Wed, May 29, 2019, 4:33 PM Jemian, Pete R. via Tech-talk <
> >> [email protected]> wrote:
> >> 
> >> Does your workstation have two active network interfaces?
> >> Some modern Linux distributions install with a hypervisor that runs the
> >> Linux OS as a guest to that hypervisor.  The hypervisor has a management
> >> network interface and the linux OS has a separate one.  Each are on the
> >> same physical network connection.
> >> 
> >> On 2019-05-29 3:28 PM, William Layne via Tech-talk wrote:
> >> > Hey all,
> >> > 
> >> > We are seeing duplicate values when first creating our subscriptions
> >> > through the CA Gateway. Is this normal? If not, does anyone know what
> >> > might be causing it?
> >> > 
> >> > Note: We are on EPICS V3.14.12.8 and Gateway 2.1.0
> >> > 
> >> > We see this in our applications and in tools such as camonitor. Here is
> >> > an example output from camonitor, for a heartbeat PV updating every
> >> 
> >> second:
> >> > $ camonitor IOC1_HEARTBEAT
> >> > IOC1_HEARTBEAT               2019-05-29 20:19:51.038659 7651
> >> > IOC1_HEARTBEAT               2019-05-29 20:19:51.038659 7651
> >> > IOC1_HEARTBEAT               2019-05-29 20:19:52.038654 7652
> >> > IOC1_HEARTBEAT               2019-05-29 20:19:53.038657 7653
> >> > ^C
> >> > 
> >> > Thanks,
> >> > William 'Casey' Layne
> >> 
> >> --
> >> ----------------------------------------------------------
> >> Pete R. Jemian, Ph.D.                 <[email protected]>
> >> Beam line Controls and Data Acquisition (BC, aka BCDA)
> >> Advanced Photon Source,    Argonne National Laboratory
> >> Argonne, IL  60439                    630 - 252 - 3189
> >> -----------------------------------------------------------
> >> 
> >>        Education is the one thing for which people
> >>        
> >>           are willing to pay yet not receive.
> >> 
> >> -----------------------------------------------------------
> >> 
> >> 
> >> 
> >> --
> >> Complexity comes for free, Simplicity you have to work for.

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