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.
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:
[[email protected] 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
[[email protected] 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.
Release: CEMUGD00200-10.1-Introscope to CA Application-Performance Management-Upgrade Mai
Component: