Connection issues frontend server
When there are any connection issues, the status of the frontend server should be checked first. To check, go to the URL http://myServer/frontend-server
.
The illustrations to the right give an overview of possible connection status that page might display.
Fehlerhafte Verbindung: ERROR
Fehlerhafte Verbindung: NOT_CONNECTED
Fehlerfreie Verbindung: CONNECTED
Connection status
| connected | note |
|---|---|
| true | A connection to the master server could be established successfully. |
| false | There is no connection to the master server. |
Logical status of the frontend server
| Status | Description |
|---|---|
| CONNECTED | The connection has been established and opened. |
| NOT_CONNECTED | No connection could be established. |
| ERROR + Fehlermeldung | An error has occurred while trying to establish a connection. Usually an error message with details will be shown. |
| DISCONNECTING | The connection is about to be closed. |
| WAIT_FOR_CONNECTION | The frontend server has been started successfully and is listening on the configured port for an initial connection attempt by the master server. |
Possible errors
Initial connection fails
- Check whether the frontend server has been started successfully and whether it is listening on the correct port.
- When it is: Check whether the frontend server can be reached from the master server, for example via Telnet. Possibles reasons it may not be reachable include:
- The firewall is blocking any connection attempt on the configured port.
- The network architecture prevents the servers from seeing each other.
- When the above applies: Check whether a key has already been assigned to the frontend server. When a key has already been assigned, an error message as shown in the screenshot to the right indicates this. Change the configuration.
- Sometimes restarting the application or the server may solve the issues.
Connection closed (Connection could be established before)
When the connection to the frontend server cannot be established again automatically, it can be opened manually from the master server.
This requires the following steps:
- Open the configuration interface of the master server in a web browser
- Login to the master server with a valid administrator (sadmin) account.
- Go to System > frontend server and try to establish a connection manually by clicking on the chain icon with a red frame to the right.
- When the chain icon appears to the left, the connection has been established successfully.
Other issues
Should all these measures fail, try the following:
- Connect to the frontend server
- Restart the Tomcat application of the frontend server
- Open the status page of the frontend server in a browser with the following URL: http:~~/~~/localhost/fs
- When the status displays as NOT_CONNECTED or WAIT_FOR_CONNECTION, the connection to the master server