Problems with connecting Desktop UI

[ask]

Hello,

I still have problems with connecting Desktop UI.

In main location we have a pair of redundant servers and several workstations with Desktop UI.
I have also workstations with Desktop UI's in some differrent geographically localizations connected via our own WAN network.
servers nad workstations are using double LAN connections.
There is no problem with network connections (servers and workstations can ping each other on both LANs.
Response time is stable and less than 10ms.
There is no special configuration for aliveTimeout, so I suppose (after the Help) the aliveTimeout is set to default it means =-10.

On this distant workstations we observe problems with connecting UI to the servers:

When WCCOAui starts (or restarts) from time to time UI does not connect to servers.
After several restarts of UI, it connects. Number of tries varies from 1 to 8.

I turned on debug and there is what I found:

1.Unsuccessful connection attempt:
a) In starting procedure UI tries to connect to both servers on both LANs = 4 connections
b) After that there is info, that workstation is connected to primary server, mxPROXY Tunnel is open,
c) Then appears info: "Closing secondary lan connection to (SYS: 0 .....)
d) Then UI sends SYS_MSG_INIT (but only to primary server do DATA manager and on first LAN only) and receives such message from server
with info about setting alive timeout to 100s. !!!
e) Then there are messages about changing source and target (but as I see there is no any change)
f) Then appears messages about new alive connectins to both servers on first LAN ony
and immediately about closing connection wihout reason
g) Procedure ends with message: "mxPROXY Tunnel is now open

But even this las message UI is not connected and is not making any further attemps.

Then I make several restarts of UI and after that


2. Successful attempt:
points a, b, c, like before.
d) Then UI sends SYS_MSG_INIT to both servers to DATA manager (but on first LAN only and receives such message from servers
with info about setting alive timeout to 100s. !!!
e) Then UI sends SYS_MSG_INIT to both servers to EVENT manager [ (but on first LAN only) and receives such message from servers
with info about setting alive timeout to 10s. !!! - it match with parameter sended by UI.
f) UI establishes connection to both servers, but on first LAN only!


Why managers sends responses to UI with different aliveTimeout parameters?
Is that reason why first attempts are failed?
Why UI does not retry to connect in case of failure?
Why UI sometime does not sending SYS_MSG_INIT to EVENT manager?

I also observe, that in case of restart secondary server, UI does not connecting to it anymore until restart UI.

Where is the problem?


Best Regards

Adam

[leoknipp]

Only with the description we cannot see where the problem is. The value for the aliveTimeout is defined by the entries on the server and the client, possibly the server has different settings than the client and therefore you see at the client an aliveTimeout which does not match the local settings.
The initialization of a WinCC OA manager connected to both redundant servers is only made by the active server, therefore the connection to the passive server is closed during the initialization.

For a detailed analysis we would need the log files with activated debug flags and the config files for the projects.
If you need further assistance please get in contact with your common WinCC OA support.

Best Regards
Leopold Knipp
Senior Support Specialist