Sentinel Control Centre does not launch

  • 7012887
  • 17-Jul-2013
  • 16-Dec-2013


Sentinel 7.1


When accessing Sentinel Control Centre from the Web UI, the following error was returned:

Unable to obtain web server host from configuration

Examining the control_center*.log files in ~/.novell/sentinel/log may show more information like:

SEVERE: Element ./web not found within GUI node in configuration.xml


There are several possible solutions to this issue.

1. Make sure that TCP port 10013 is open on the firewall. Confirm this with
netcat -zv <ip addr> 10013
telnet <ip addr> 10013

2. Make sure you are using a supported browser and using the latest Java Webstart.
  for supported versions.

3. Make sure you have the correct control_center.jnlp downloaded from the Sentinel server and not a newer or older version from another server.

4. Access the web UI via the DNS name (e.g. rather than the IP address. You may need to add this entry to your workstation hosts file if your DNS server is not yet updated.

5.  Use a java version prior to Oracle Java 7 update 45. See below

Over the last few months, Oracle has been rapidly making security changes to their Java Webstart technology with the goal of tightening up the overall level of security that they provide. They have informed us that this process will continue, with major changes to come.

Sentinel and Sentinel Log Manager leverage Java Webstart as a way to deliver our Java-based user applications — the Sentinel Control Center, Solution Designer, and Event Source Manager — to desktop systems. This has been a successful approach that eliminates the need to permanently install the user application software locally. Unfortunately, this also means that if Oracle changes the behavior of Java Webstart, those changes could affect the behavior of our user applications up to and including preventing them from starting entirely. We have already seen issues like this happening:

-    Oracle Java 7 update 40 made unannounced changes to the Webstart logging framework that prevented our user applications from starting properly.  There is a workaround for this issue by opening the Java Control Panel and then going to the Advanced Tab > Debugging > select Enable Logging.

-    Oracle Java 7 update 45 made unannounced changes to restrictions placed on the .jnlp file that prevented our user applications from starting properly.  There is no known workaround for this issue on Sentinel versions before 7.1.1 other than downgrading to Java 7 update 40. Upgrading to Sentinel 7.1.1 will correct issues with this version of Oracle Java.

6.  Update Sentinel Control Centre to 7.1.1 or later. Sentinel 7.1.1 will work correctly with current versions of Oracle Java.