This topic describes considerations in planning the availability and scalability of the Application Object Server (AOS).

In Microsoft Dynamics AX 2009, you can create a single or multiple named AOS clusters and place one or more AOS servers in a named cluster. All AOS servers in a named cluster serve clients based on total number of client connections. The number of AOS servers you place in a cluster depends upon the workload created by the Microsoft Dynamics AX application and the performance objectives you have set.

Whether you create a single cluster or multiple clusters depends upon your requirements. For a sample topology with a single AOS cluster, see Large-scale deployment. For a sample topology with two clusters, see Large-scale distributed deployment.

Note Note

The load balanced clustering does not take into consideration the server resources used by active clients and other Microsoft Dynamics AX components. If you have an application like BizTalk Server processing a large volume of transactions, it is still considered one connection for load balancing. Therefore, you need to consider placing high-volume applications on a cluster separate from online clients.

An AOS server is usually part of a named cluster and participates in one of the following server roles. Each server role is covered in a separate topic in this section:

  • Dedicated load-balancer:When configured as a dedicated load balancer, an AOS server does not participate in servicing client requests as an active AOS or as a batch server. It responds only to initial client requests and provides a list of AOS servers that will serve client requests.

  • AOS server in a cluster without a dedicated load balancer:When an AOS server is placed in a cluster without a dedicated load balancer, the AOS server acts as a load balancer and an AOS. Therefore, it will respond to initial client queries and provide a list of AOS servers. It will also serve client requests for all clients connected to it.

  • Batch server:When configured as a batch server, the AOS server can run batch jobs. Only an active AOS server can be configured as a batch server. You cannot configure a load-balancer AOS server as a batch server.

The following topics are included in this section:

Standalone AOS server

Batch server

AOS clusters with a dedicated load balancer

AOS clusters without a dedicated load balancer

For additional information

The following table provides descriptions of forms you can refer to for more information.

Form or help file


Online usersform ( Administration > Online users)

Allows you to configure the AOS server to reject new clients. The Server Instancestab in the form also provides a list of clients connected to this AOS server.

Cluster configurationform ( Administration > Cluster configuration)

Allows you to change the load balancer option as well as the maximum concurrent sessions allowed for the AOS server.

Server configurationform ( Administration > Server configuration)

Allows you to configure AOS settings including settings for clustering and batch server.