Running WVCtrl.sh fails to launch WebView.

Document ID : KB000032748
Last Modified Date : 14/02/2018
Show Technical Document Details

 Summary:

  In the later releases of WebView (from APM 9.7 and later), we provide a WVCtrl.sh script for stopping, starting or querying the status of WebView.

  The script relies on checking for the availability of the Enterprise Manager. So, WebView will only be started if the Enterprise Manager is responding.

  This is a tip from personal experience where the script was not starting up WebView successfully.

  I  was working specifically on APM 10.1.

 

 Instructions:

 WVCtrl.sh will either look for nc or telnet installed on the OS in the /usr/bin directory.

  I refer below to telnet as this is what I chose to resolve the problem.

 

  By default, the script will try to connect 50 times to the Enterprise Manager with a one minute sleep interval.

  On a machine where telnet is not installed, the script will cycle through the 50 attempts posting this message "Reconnect attempt to EM: 1, 2 etc." Then you will    have this error - the example is taken from the script so the variables will be replaced by values found in IntroscopeWebView.properties:

 "Error: Unable to connect to MOM/EM on $MOM_HOST : ${MOM_PORT}"

 

  Debugging the script

  As a general troubleshooting tip for the script, you can use the sh -x command prefix to see exactly what is happening:

  [root@apm bin]#sh - x ./WVCtrl.sh start

  A request with telnet not installed will have a section looking like below with nothing in the RESP entry

  ++ /usr/bin/telnet apm 5001
  + RESP=
  ++ echo
  ++ grep Connected
  + success=
  + '[' -n '' ']'
  ++ expr 0 + 1
  + count=1
  + echo 'Reconnect attempt to EM: 1'

 

  This is the section of the script showing it working, we can see it trying to connect then connecting successfully

  ++ /usr/bin/telnet apm 5001
  + RESP='Trying 1.2.3.4...
  Connected to apm

 

  Successful startup

 

  With telnet installed you should then get a successful startup like this

  [root@apm bin]# ./WVCtrl.sh start
  Using APMHOME: /opt/Introscope10.1.0.15
  Using JAVA_HOME: ../jre

  Using EM Host: apm

  Using EM Port: 5001
  MOM/EM is running..
  JVM PID is  15700
  ./WVCtrl.sh start: Starting APM WebView...
  WebView running on port 8180
  Successfully started WebView server. Please check log file for more details.

  I did also test by having nc installed instead of telnet. This resolves the problem in the same way.