Connection Problems

If the Test Connection button returns an error, or a server shows as unreachable after saving, use this guide to diagnose the issue.

Checklist

1. Is the broker running?

Verify the broker process is up before anything else.

• RabbitMQ: open http://localhost:15672 in your browser — the management UI should load.
• ActiveMQ Classic: open http://localhost:8161/admin.
• ActiveMQ Artemis: open http://localhost:8161.

If the UI does not load, the broker is not running or the port is different.

2. Is the management API enabled?

HZN Queue Console connects to the broker’s HTTP management API, not the AMQP or OpenWire port.

• RabbitMQ: the rabbitmq_management plugin must be enabled. Run rabbitmq-plugins enable rabbitmq_management and restart the broker.
• ActiveMQ Classic / Artemis: the web console / Jolokia API must be enabled (it is on by default in most distributions).

3. Is the hostname and port correct?

If the broker is remote, check the port first: 15672 and 8161 are the broker’s own ports and are usually closed to the outside. A hosted or reverse-proxied broker publishes its management API on 443 — see Brokers published only on 443.

Enter only the hostname (without trailing slash) and the port as a separate field.

4. Firewall or VPN blocking the port?

If connecting to a remote broker:

• Confirm the management port is open in the server’s firewall.
• If using a VPN, ensure the VPN is connected and routes traffic to the broker host.
• Test from the command line: curl http://<host>:<port>/api/overview -u guest:guest

5. Wrong credentials?

The default credentials for RabbitMQ are guest / guest, but the guest user can only connect from localhost by default. Create a dedicated management user for remote access:

rabbitmqctl add_user hzn <password>
rabbitmqctl set_user_tags hzn administrator
rabbitmqctl set_permissions -p / hzn ".*" ".*" ".*"

6. TLS / HTTPS connection

If the broker uses HTTPS:

• Use https:// as the scheme in the hostname field.
• Self-signed certificates are supported. If the connection fails due to an untrusted certificate, add the certificate to your OS trust store.
• Make sure the TLS port is open (RabbitMQ TLS management default: 15671).

7. Reverse proxy

If the broker is behind a reverse proxy (nginx, Traefik, etc.):

• Enter the proxy URL including any path prefix, e.g. http://myhost/rabbitmq.
• Put the proxy’s port in the port field — usually 443 or 80, not the broker’s own 15672. The app inserts the port in front of the path, so https://myhost/rabbitmq with port 443 is requested as https://myhost:443/rabbitmq/api/overview.
• Make sure the proxy forwards the Host header and does not strip the management API path.
• WebSocket upgrades are not required — the app uses plain HTTP/HTTPS.
• Spy Mode does not go through the proxy: it opens a direct AMQP connection to the same host on the AMQP port, which therefore has to be reachable from your machine as well. If the broker is published only as https://myserver/, AMQP may be routed through 443 too — enter 443 as the AMQP port, but note that it works only when the proxy forwards plain AMQP, since Spy Mode does not negotiate TLS. See Brokers published only on 443.
• If that AMQP port is simply not reachable from your machine, leave the field empty. Spy Mode and AsyncAPI recording then stay off for this server — the console does not fall back to 5672 — and everything else keeps running over the management API.

Error Messages

Related

• Server Connections — adding and editing server connections
• Getting Started — default connection values