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This product reached the end of support date on March 31, 2021.

Appmon Server not running on port 8021



I am trying to install the AppMon however I am running into some issues.

I have followed these instructions to install and then start the server and collector. Everything runs fine, except that the server is not listening on port 8021 but on port 50005. This means I cannot access https://localhost:8021 but I can also not access https://localhost:8021 through any browser, where it keeps loading.

All other services run as expected i.e. port 2021, 6699 and 9998 are all being used.

Is this a firewall issue or what? I'd appreciate any help.


Dynatrace Pro
Dynatrace Pro

Are you able to connect to the dynatrace server via the client? If so you can check the server settings via the settings tab to see what services are listening on what ports. Id recommend you try localhost port 9911 in addition to localhost 50005 on your web browser to see what shows up. Hope this helps.



Yes, I can connect to localhost port 9911. Is this the client or the server?
And how come it is on 9911 rather than 8021 as mentioned in the documetntation.

Dynatrace Leader
Dynatrace Leader

There are two web interfaces. 8021 is the admin interface. 9911 is the User interface.

But you likely also want to look at the rich client, which talks on 2021 to the AppMon Server.

The 50005 port is likely an internal port, that is not something the user should worry about.

If 8021 is not working, even from localhost, then perhaps someone changed the default port. The Rich client can be used to change all these ports. I would inspect the AppMon server log files (server.0.0.log) to see if something is wrong when it trys to listen on 8021. It's possible someone disabled this listener. THere's a checkbox to easily disable this listener, via the Rich client -> Settings -> Dynatrace Server -> Services.

netstat shows that port 2021 is open and listening. However, when I try to access it through the browser, it downloads a binary file.

Here is something interesting that I found in the log files:

2016-12-12 12:08:58 INFO [SecuringJettyModule] Removing unsafe ciphers from Jetty instance at port 8021:

2016-12-12 12:08:58 INFO [SecuringJettyModule] Removing unsafe protocols from Jetty instance at port 8021: [SSLv2, SSLv3, SSLv2Hello]
2016-12-12 12:08:58

WARNING [ServerServiceTrackerCustomizer] HTTP Server listener(s) cannot be started, please edit server.config.xml for alternative ports.

FYI, port 8021 is not being used by anything else. netstat -an | grep 8021 shows nothing.


Turns out port 8020 was being used by another process due to which http server listeners could not be started. Thanks for the help 🙂

DynaMight Leader
DynaMight Leader

Dear NoorUllah,

Port # 9911 is a default port for the web dashboards.

Port # 8020 and 8021 to use from Browser to Server to access Web interface for RESTful Server administration, to start the Webstart Client.

Port # 8020 is a HTTP and 8021 HTTPS

The below documentation link is about communication connections: