An Amazon Elastic Load Balancer unites multiple 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 Server Cloud Builder on Amazon Web Services creates a load balancer when you build an ArcGIS Server site, and all the instances in your site are placed under it. Also, any instances created by your auto scaling rules are placed under the load balancer. You see the load balancer address when you examine the URL to your site. Similarly, if you use the Esri sample Amazon CloudFormation templates, the templates create the required load balancers and place 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 an Amazon Load Balancer.
- 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.
- Add your ArcGIS Server instances to the load balancer