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 serves as the single point of contact for clients. The load balancer distributes incoming application traffic across multiple targets, such as EC2 instances, in multiple Availability Zones. This increases the availability of your application. You add one or more listeners to your load balancer.
• A listener checks for connection requests from clients, using the protocol and port that you configure, and forwards requests to one or more target groups, based on the rules that you define. Each rule specifies a target group, condition, and priority. When the condition is met, the traffic is forwarded to the target group. You must define a default rule for each listener, and you can add rules that specify different target groups based on the content of the request (also known as content-based routing). Each target group routes requests to one or more registered targets, such as EC2 instances, using the protocol and port number that you specify. You can register a target with multiple target groups. You can configure health checks on a per target group basis. Health checks are performed on all targets registered to a target group that is specified in a listener rule for your load balancer.
An Application Load Balancer functions at the application layer, the seventh layer of the Open Systems Interconnection (OSI) model. After the load balancer receives a request, it evaluates the listener rules in priority order to determine which rule to apply, and then selects a target from the target group for the rule action using the round robin routing algorithm. Note that you can configure listener rules to route requests to different target groups based on the content of the application traffic.
Routing is performed independently for each target group, even when a target is registered with multiple target groups. You can add and remove targets 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.
You can configure health checks, which are used to monitor the health of the registered targets so that the load balancer can send requests only to the healthy targets.