Staged HTTP > High availability staged HTTP

High availability staged HTTP

The following figure shows the staged HTTP servlet in a high availability configuration to handle inbound traffic. This involves setting up servlets on multiple web servers. A load balancer is used to direct traffic to each web server. The partner uses the virtual IP address of the load balancer in sending messages.

In this clustered example, each instance of Activator needs a staged HTTP delivery exchange for receiving messages from partners.

A high-availability inbound staged HTTP configuration for inbound message handling.

The following describes the process illustrated in the figure.

  1. Inbound documents are routed to either staged HTTP servlet.
  2. The staged HTTP servlet receives the request and persists it to temporary storage (non-clustered storage). If the message requires a synchronous acknowledgement, the inbound connection is held open.
  3. Each instance of Activator is configured to poll each staged HTTP servlet.
  4. Activator receives inbound document by issuing:
    1. HTTP GET for listing of all inbound documents.
    2. HTTP GET for each inbound document
    3. HTTP DELETE to remove the document from temporary storage.
  5. If the received message requires a synchronous acknowledgement, Activator produces the acknowledgement back to the consuming staged HTTP servlet so it can be produced back to the original inbound connection.

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