Remove internal load balancer

Please note that this workshop has been archived and is not actively maintained. On September 30, 2026, AWS will discontinue support for AWS App Mesh. For more information, visit this blog post.

Now that we could see that the Crystal backend service is working without using the Load Balancer, we can shift 100% of the traffic to it and delete the old service and the internal LB.

To do so, let’s start shifting 100% of the traffic to the virtual node with the Cloud Map integration:

# Define variables #
SPEC=$(cat <<-EOF
  { 
    "httpRoute": {
      "action": { 
        "weightedTargets": [
          {
            "virtualNode": "crystal-sd-vanilla",
            "weight": 1
          }
        ]
      },
      "match": {
        "prefix": "/"
      }
    },
    "priority": 10
  }
EOF
); \
# Update app mesh route #
aws appmesh update-route \
  --mesh-name appmesh-workshop \
  --virtual-router-name crystal-router \
  --route-name crystal-traffic-route \
  --spec "$SPEC"

After redirecting all the traffic to the new virtual node with the service discovery attributes, let’s delete the old ECS service and the internal Load Balancer:

# Define variables
CLUSTER_NAME=$(jq < cfn-output.json -r '.EcsClusterName');
INTERNAL_LB_ARN=$(jq < cfn-output.json -r '.InternalLoadBalancerArn');
# Delete ecs service
aws ecs delete-service \
  --cluster $CLUSTER_NAME \
  --service crystal-service-lb \
  --force
# Delete load lalancer
aws elbv2 delete-load-balancer \
  --load-balancer-arn $INTERNAL_LB_ARN
  • Update the CNAME record in Route53 to crystal.appmeshworkshop.pvt.local
# Define variables
HOSTED_ZONE_ID=$(aws route53 list-hosted-zones-by-name \
    --dns-name appmeshworkshop.hosted.local \
    --max-items 1 | \
  jq -r ' .HostedZones | first | .Id');
RECORD_SET=$(aws route53 list-resource-record-sets --hosted-zone-id=$HOSTED_ZONE_ID | \
 jq -r '.ResourceRecordSets[] | select (.Name == "crystal.appmeshworkshop.hosted.local.")');
cat <<-EOF > /tmp/update_r53.json
{
  "Comment": "UPDATE crystal.appmeshworkshop.hosted.local",
  "Changes": [
    {
      "Action": "DELETE",
      "ResourceRecordSet": $RECORD_SET
    },
    {
      "Action": "CREATE",
      "ResourceRecordSet": {
        "Name": "crystal.appmeshworkshop.hosted.local",
        "Type": "CNAME",
        "TTL": 300,
        "ResourceRecords": [
          { "Value": "crystal.appmeshworkshop.pvt.local." }
        ]
      }
    }
  ]
}
EOF
# Change route53 record set
aws route53 change-resource-record-sets \
  --hosted-zone-id $HOSTED_ZONE_ID \
  --change-batch file:///tmp/update_r53.json

You can now go ahead and test your application again to make sure everything is still working.