Checking node connections (AEN 4.2.1)

When the AEN nodes cannot communicate with each other as intended, it can cause issues with you AEN platform installation.

Verifying server to gateway connectivity

1. On the server, in the AEN navigation bar, click Admin to open the Admin Settings page.

2. In the Site Admin menu, select Data Centers:

   
   
   

3. For each data center in the list, check connectivity from the server to that gateway.

   EXAMPLE: The gateway in this example is http://gateway.example.com:8089:

   root@server # curl --connect-timeout 5 http://gateway.example.com:8089 > /dev/null
   

Verifying gateway to compute node connectivity

1. On the server, in the AEN navigation bar, click Admin to open the Admin Settings page.

2. In the Providers menu, select Enterprise Resources:

   
   
   

3. Open each compute node in the Resources section.

4. Verify that the contents of the URL field begin with either http or https.

   
   
   

5. Check connectivity to that URL from the corresponding gateway.

   EXAMPLE: The gateway in this example is http://gateway.example.com:8089:

   root@gateway # curl --connect-timeout 5 http://compute.example.com:5002 > /dev/null
   

Verifying gateway to server connectivity

The gateway-to-server path is used by the gateway configuration command wk-gateway-configure.

1. Verify that the gateway is linked to the correct server in the configuration file.

2. Verify that the full server URL is specified.

3. Check connectivity to the server:

   root@gateway # grep WAKARI_SERVER /opt/wakari/wakari-gateway/etc/wakari/wk-gateway-config.json
     "WAKARI_SERVER": "http://wakari.example.com",
   
   root@gateway # curl --connect-timeout 5 http://wakari.example.com > /dev/null
   root@gateway # curl --connect-timeout 5 http://error.example.com > /dev/null
   curl: (7) Failed to connect to error.example.com port 80: Connection refused
   

4. If a connection fails:

   1. Ensure that gateways (data centers) and compute nodes (Enterprise Resources) are correctly configured on the server.

   2. Verify that processes are listening on the configured ports:

      $ sudo netstat -nplt
      Active Internet connections (only servers)
      Proto Recv-Q Send-Q Local Address   Foreign Address State  PID/Program
      tcp        0      0 *:80            *:*             LISTEN 26409/nginx
      tcp        0      0 *:22            *:*             LISTEN 986/sshd
      tcp        0      0 127.0.0.1:25    *:*             LISTEN 1063/master
      tcp        0      0 *:5000          *:*             LISTEN 26192/python
      tcp        0      0 127.0.0.1:27017 *:*             LISTEN 29261/mongod
      tcp        0      0 *:22            *:*             LISTEN 986/sshd
      tcp        0      0 127.0.0.1:25    *:*             LISTEN 1063/master
      

   3. Check the firewall setting and logs on both hosts to ensure that packets are not being blocked or discarded.