You can update the Edge-LB pool configuration to reflect changing requirements for a service without any service disruption. Making changes to an Edge-LB pool configuration does not affect any existing load-balancing operations in the cluster. You can also make changes to the pool configuration without editing the same .json file you have previously deployed. For example, you can expose and deploy a service using the app-lb-1.json pool configuration file, then update the Edge-LB pool configuration for that service by deploying different settings in a new app-lb-2.json pool configuration file.

If you need to update pool configuration settings after deployment, you can choose to do either of the following:

• Update and maintain a single pool configuration file for a service to simplify pool management.
• Keep different pool configuration settings in separate files for a service to simplify how you respond to and adapt load balancing operations to address changing network traffic patterns or cluster requirements.

Before you begin

You must have:

• Edge-LB installed as described in the Edge-LB installation instructions.
• The core DC/OS command-line interface (CLI) installed and configured to communicate with the DC/OS cluster.
• The edgelb command-line interface (CLI) installed.
• An active and properly-configured DC/OS Enterprise cluster.

To update a pool configuration

1. Copy and paste the following sample Edge-LB pool configuration to create the nginx-lb.json file:

   {
   "apiVersion": "V2",
   "name": "nginx-lb",
   "count": 1,
   "haproxy": {
       "frontends": [
       {
       "bindPort": 15002,
       "protocol": "HTTP",
       "linkBackend": {
           "defaultBackend": "nginx-backend"
       }
       }
   ],
       "backends": [
       {
       "name": "nginx-backend",
       "protocol": "HTTP",
       "services": [
           {
           "marathon": {
           "serviceID": "/nginx"
           },
           "endpoint": {
           "portName": "nginx-port"
           }
       }
       ]
       }
   ],
       "stats": {
       "bindPort": 0
       }
   }
   }
   

   This sample Edge-LB pool configuration file deploys one Edge-LB pool instance using the "count": 1 setting.

2. Change the count pool instance variable to 3 to scale up the number of Edge-LB pool instances.

   "count": 3
   

3. Update the Edge-LB pool:

   dcos edgelb update nginx-lb.json
   

4. Verify that the pool configuration was updated:

   dcos edgelb status nginx-lb
   

5. Verify the endpoints that Edge-LB pools are deployed on the public agents:

   dcos edgelb endpoints nginx-lb