ArcGIS Server architectures on Amazon Web Services

ArcGIS Server Cloud Builder on Amazon Web Services gives you various options for your ArcGIS Server site architecture. For example, you can choose to put multiple GIS server instances in your site to handle large processing loads, and you can choose to put the geodatabase on its own instance to isolate it from the GIS server tier. This topic discusses the architecture options available when building your site with Cloud Builder. It also explains architecture guidelines and limitations if you're building your site manually using the AWS Management Console.

Architectures available with Cloud Builder

ArcGIS Server Cloud Builder on Amazon Web Services allows you to build a simple site with one GIS server to a complex site with many GIS servers. It also allows you to include an enterprise geodatabase and determine where the enterprise geodatabase is placed.

ArcGIS Server without an enterprise geodatabase

You can use Cloud Builder to create an ArcGIS Server site running on Windows or Linux without an enterprise geodatabase. Such a site can have one or many GIS servers. All the participating GIS servers must use the same operating system. In all cases, the GIS server or servers are placed beneath an Elastic Load Balancer (ELB).

ArcGIS Server with an enterprise geodatabase on the same EC2 instance

You can optionally choose to create a site that has an enterprise geodatabase running on the same EC2 instance as ArcGIS Server. If the site contains multiple GIS servers, the enterprise geodatabase runs on just one of those servers.

If you built your ArcGIS Server site on Linux, the enterprise geodatabase runs on PostgreSQL. If you build your ArcGIS Server site on Windows, the enterprise geodatabase can run on Microsoft SQL Server Express or SQL Server Standard.

Running the enterprise geodatabase on the same EC2 instance as ArcGIS Server can help you save hardware costs (the hourly fees you pay to Amazon for use of the instances). This architecture also reduces latency between the server and the database. However, when you run the server and the database on the same EC2 instance, you are sharing hardware resources and run a greater risk of site disruption if either component is overloaded or goes offline.

ArcGIS Server with an enterprise geodatabase on its own EC2 instance

You can choose to create a site that has an enterprise geodatabase running on its own EC2 instance, separate from the ArcGIS Server EC2 instance(s). If you built your ArcGIS Server site on Linux, the enterprise geodatabase runs on PostgreSQL. If you built your site on Windows, the enterprise geodatabase runs on SQL Server Standard.

Running the enterprise geodatabase on a separate instance from ArcGIS Server can result in increased fees for instance usage. However, separating the GIS server and database tiers gives you more freedom to adjust or fix one tier without affecting the other.

Architectures available when building your site manually

When you build your site manually using the AWS Management Console, you can launch one or many EC2 instances running ArcGIS Server. If you launch multiple instances, you must also launch an ELB and add the instances to it. All ArcGIS Server instances you add beneath the ELB must be identical.

Each ArcGIS Server instance beneath the ELB operates independently of the other instances beneath the ELB. In other words, each instance has its own configuration store, server directories, logs, and so forth. This limits the types of things you can do with the server, such as asynchronous geoprocessing or distributed map caching jobs. If you want a genuine distributed architecture that can do those types of things, use Cloud Builder to create your site.

There are three Amazon Machine Images (AMIs) you can choose when launching instances for your site, or you can use a custom AMI that you have derived from one of these three AMIs. For descriptions of the AMIs, see The ArcGIS Server AMIs. All the AMIs include ArcGIS Server and an enterprise geodatabase. If you want to run the enterprise geodatabase on a separate instance from ArcGIS Server, it's recommended that you use Cloud Builder to create your site.

Do I need to install the ArcGIS Web Adaptor?

ArcGIS Server Cloud Builder on Amazon Web Services does not install or configure the ArcGIS Web Adaptor because the Elastic Load Balancer (ELB) plays many of the same roles, distributing incoming requests among the GIS servers in your site. However, after you create your site, you can optionally log in to your instance and download the Web Adaptor setup from the Esri Customer Care website. This is necessary if you'll be hosting ArcGIS API for JavaScript applications on a Windows instance. See Deploying a web application on a Windows site for more details.

12/10/2013