The UDA channel is for Teradata’s Unified Data Architecture including the Analytical Ecosystem and other UDA influences. This channel provides information specific to the integration and co-existence of multiple systems, in particular when a mix of Aster, Teradata, and Hadoop are present. It is also meant to support information around the UDA enabling technologies so products like Viewpoint, Data Mover, Connectors, QueryGrid, etc.
• A load balancer distributes incoming application traffic across multiple EC2 instances in multiple Availability Zones. This increases the fault tolerance of your applications. Elastic Load Balancing detects unhealthy instances and routes traffic only to healthy instances. Your load balancer serves as a single point of contact for clients. This increases the availability of your application. You can add and remove instances from your load balancer as your needs change, without disrupting the overall flow of requests to your application. Elastic Load Balancing scales your load balancer as traffic to your application changes over time. Elastic Load Balancing can scale to the vast majority of workloads automatically.
• A listener checks for connection requests from clients, using the protocol and port that you configure, and forwards requests to one or more registered instances using the protocol and port number that you configure. You add one or more listeners to your load balancer. You can configure health checks, which are used to monitor the health of the of the registered instances so that the load balancer can send requests only to the healthy instances.
• To ensure that your registered instances are able to handle the request load in each Availability Zone, it is important to keep approximately the same number of instances in each Availability Zone registered with the load balancer. For example, if you have ten instances in Availability Zone us-west-2a and two instances in us-west-2b, the requests are distributed evenly between the two Availability Zones. As a result, the two instances in us-west-2b serve the same amount of traffic as the ten instances in uswest- 2a. Instead, you should have six instances in each Availability Zone. By default, the load balancer distributes traffic evenly across the Availability Zones that you enable for your load balancer. To distribute traffic evenly across all registered instances in all enabled Availability Zones, enable cross-zone load balancing on your load balancer. However, we still recommend that you maintain approximately equivalent numbers of instances in each Availability Zone for better fault tolerance.