Experimental Physics and
Industrial Control System

Ralph Lange <[email protected]> · Tue, 11 Dec 2007 17:25:56 +0100

Hello Pete,
Leicester, PJ (Pete) wrote:

A have a few gateway question:-

1) We have just configured a couple of new gateways. When we first ran
them they repeatedly wrote the following error message to the gateway
log file every 15 seconds even though the gateway appeared to be
working OK.

../../../../src/cas/io/bsdSocket/casDGIntfIO.cc: CA beacon socket
disconnect error was "Network is unreachable"

Dec 11 12:02:34 !!! Errlog message received (message is above)

After some experimentation we found we could get rid of the error by
adding a 'default' route to the routing tables on the host machine. We
actually set up a default route to a non-existent IP address.

Is this a problem with the gateway software or have we missed
something in our gateway configuration? (We are running gateway
version 2.0.0.0)

I've never seen this message - looks to me as if the server side of the
Gateway is not able to send UDP broadcasts (beacons). That would
probably make it a network configuration issue of the host machine
rather than a Gateway software or configuration problem.

But I better leave this for Jeff to answer.
2) I notice that a '-archive' option has appeared in the latest
gateway. We currently run a separate additional gateway exclusively
for our archiver with the '-mask l' option to ensure we don't archive
anything based on MDEL (a parallel gateway serves PV's to edm and
other clients). What is the difference between '-archive' and '-mask
l'? Should I now revert to having a single 'gateway -archive' for
both the archiver and other (edm) clients? Would I gain/lose anything?

We did make this transition recently - there should not be a noticeable
functional difference.

The '-mask' options sets the flags for all client connections of the
Gateway, the '-archive' flag tells the Gateway to open a second client
connection using the archive flag as soon as a client connects that uses
the archive flag. So, '-archive' does more or less automatically what
you've been doing manually so far.

In both cases will regular clients get the regular (MDEL based) updates,
while archiver clients will get the archive (ADEL based) events.
The only difference I can see right now:

With an existing regular (archive) connection, the first archiver
(regular) client connecting to the same channel would issue a new name
resolution broadcast on the client side and open a new tcp connection in
the two-process layout, while the single process would not broadcast the
name and only set up a new event subscription using the existing tcp
connection (as it already is connected to the channel).
3) Where do I find a summary of the changes between gateway version
2.0.0.0 and the two later versions 2.0.2.0 and 2.0.2.1?

Dirk's slides of the April 2007 EPICS meeting at DESY
(ftp://ftp.desy.de/pub/EPICS/meeting-2007/ChannelAccessGatewayUpdate.pdf)
should cover the main changes.
Hope this helps,
Ralph

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System