An Amazon Elastic Load Balancer unites multiple Amazon Elastic Compute Cloud (EC2) instances under a common web address. The load balancer plays the role of the web gateway in the ArcGIS Enterprise architecture and prevents any one of the ArcGIS Server machines from being overwhelmed with incoming requests. This allows you to use all the ArcGIS Server machines under the load balancer to respond to requests.
ArcGIS Enterprise Cloud Builder Command Line Interface for Amazon Web Services and Esri sample Amazon Web Services (AWS) CloudFormation templates create load balancers when you deploy and place ArcGIS Server instances under them.
If you build your site using the AWS Management Console, you need to create load balancers yourself and add your AWS instances to it.
Use a load balancer to direct traffic to different ArcGIS Server machines
Follow these steps to use a load balancer with stand-alone ArcGIS Server sites:
- Create a classic Elastic Load Balancer in the AWS Management Console.
- Launch one EC2 instance running ArcGIS Server.
- Load your data and applications on the instance.
- Launch more ArcGIS Server instances, either manually or through auto scaling.
It's recommended that you add instances from a variety of availability zones. This way you still have a running instance if a zone becomes weakened or disabled for any reason. Amazon recommends maintaining the same number of instances in each availability zone because the load balancer distributes traffic equally across availability zones.
- Add your ArcGIS Server instances to the load balancer.