SIMCA-online 14 clients stop updating, display Not Responding in window title (Q859)

The information in this article applies to: 
SIMCA-online 14
Symptoms: 

All SIMCA-online clients connected to a server become unresponsive. Plots can no longer be opened, already opened plots are no longer updated, it is not possible to connect to the server, "Not Responding" is shown in the caption of the client, the client is disconnected from the server.

At the same time the CPU usage for the SIMCA-online server service drops to near 0%, the only thing written to the server log is "Tested all (N) client connections" if the server log level is set to Debug.

This happens in rare circumstances when the following conditions are true;

  • SimApi function calls to access data are very slow (typically more than a second for each function call, as can be seen in debug-level server logs). This can happen when the SIMCA-online server is located far from the data source and the resulting network connection has a high latency and low bandwidth.
  • Two or more clients are connected to the SIMCA-online server, both with an administrator logged on and with the Project Administration window open.
  • A reprediction is started from the Project Administration window in one client.
Cause: 

The SIMCA-online server has encountered a full system deadlock when a client updates the Project Administration window at the same time as the reprediction starts.

Resolution: 

When this happens the server process has to be stopped and restarted. Note that no data-loss occurs because of this problem, the server will catch-up any previous activity when it is restarted, following the settings for catch-up of the configurations on the server.

Workaround: 

Close the Project Administration window after using it to reduce the risk of hanging the server.

Instead of repredicting from the Project Administration window, perform the reprediction from the opened configuration on the Administration-tab of the ribbon.

Status: 

This is fixed in SIMCA-online 14.0.1.

Date modified: Feb 23, 2017
Article type: 
Problem