Experimental Physics and
Industrial Control System

Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov> · Tue, 10 Nov 2020 10:40:58 -0800

On 11/10/20 9:28 AM, Wlodek, Jakub via Tech-talk wrote:
> Hi all,
> 
> I am currently working with an areaDetector IOC I am running in a container, and I am running into
> some issues getting the PVA Image display working correctly. When I start the IOC, I don't see
> any errors around the startPvaServer call, other than a note that it will use a dynamically
> assigned TCP port. I can see the pva server using this port via `pvlist`, and I can see the
> PV name for the Image PV through the IOC shell using `pval`, however, I can't seem to see
> the PV in any of the PVA clients. In CSS it shows as disconnected, while if I run pvget, I get the following error
> message when trying to communicate with the server from within the container (actual server IP replaced with 11.11.11 just in case):

...

> Here is what I get when I run pvlist:
> 
> GUID 0x42F0685F000000003BA10E0B version 1: tcp@[ 11.11.11.3:58739 ]
> GUID 0x6EB8685F000000006EEF252B version 1: tcp@[ 11.11.11.3:5075 ]
> GUID 0x7BC9AA5F00000000CA5B0023 version 2: tcp@[ 11.11.11.3:60307 ]
> 
> The PVA server created by this IOC is the one marked as version 2. I'm guessing I am doing something wrong when it comes to the network
> configuration - if anyone has an idea what that could be please let me know. All other (Channel Access) PVs seem to be visible just fine
> both inside and outside the container.

I've not seen this error before.  The "failed to be validated" error occurs when
a new connection expires a 5 second timeout (unfortunately hardcoded) without
completing the authentication step.

I doubt that this is configuration problem.  The UDP search step succeeds, and
the TCP connection is established.

Are you able to run and connect to the softIocPVA executable started with some dummy records?

Also, if you connect connect to the (dynamically assigned) TCP port with telnet,
do you see something like:

> $ telnet localhost 5075
> Trying ::1...
> Trying 127.0.0.1...
> Connected to localhost.
> Escape character is '^]'.
> �A�@D   anonymousca^]

Going beyond that, if you are so inclined, you can run a packet capture
and analyze it with pva.lua from:

https://github.com/mdavidsaver/cashark

What you see can be compared against some known working sessions.
eg. test/pva-connect.pcapng and test/pva-ops.pcapng

> wireshark -X lua_script:pva.lua test/pva-connect.pcapng

I'm interested to know if you see the CONNECTION_VALIDATION messages
being exchanged.  There should be one from server to client (telnet
shows this), which should be followed by another from client to server.
You will see your user account name in the body of this one.

If all were going well, the server would then respond with CONNECTION_VALIDATED.
But since both ends are timing out, presumably this isn't happening.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System