If you have deployed Platform on more than one host you may need to make changes to firewalls for the application to connect successfully. Firewalls can block connections to the Kx Control Application from the Web Tier (AppServer/Tomcat) if it is deployed on a separate host.
If you are having problems with your Dashboards connecting to the Control back end, it is sometime best to simplify the problem. This can be done by using netcat (
nc) to take the platform stack out of the equation and debug at a connection level.
To run this test, shut down Platform and all its components.
On the Control host run the following command to listen for TCP connections. The port used should be the port you are running Control on (
grep DELTACONTROL_PORT delta.profile).
$ nc -l 2001
On your AppServer host attempt to connect to the listening process on the Control host as follows:
$ nc <controlhost> 2001
The host name above should be the hostname or IP address where you are running the
nc -l command.
If a firewall is blocking the connection the command above will fail (
Ncat: Connection refused) or hang and eventually time out.
If this happens then you need to try and diagnose what is blocking the connection.
If the connection is successful, you should be able to enter text in the AppServer nc terminal and when you hit Return it should appear on the Control terminal. If the connection is successful but you are still having issues with the Dashboards then you need to reach out to Support.
The most common issues seen with fresh installations is that a software firewall (
firewalld) is running on the deploy host.
You can check the status of
firewalld by running the following:
$ systemctl status firewalld firewalld.service - firewalld - dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled) Active: active (running) since Sat 2013-04-06 22:56:59 CEST; 2 days ago Main PID: 688 (firewalld) CGroup: name=systemd:/system/firewalld.service
If the firewall is active you can disable and stop it by running the following commands as root:
$ systemctl disable firewalld $ systemctl stop firewalld
If you don’t have root access you will need to contact your Unix team to either disable
firewalld for you or add rules for the ports you are trying to connect to.
If you have confirmed that a software firewall is not blocking connections on a certain port then you should talk to your network team and ensure that there are no network firewalls running which may block access to your application.