Friday, January 30, 2009

ESB internal topics

One of the queries I used to get in ESB was on the role of different JMS topics used in ESB.

I am listing down the main topics used in ESB.

There are 2 parts of the ESB engine - ESB designtime server & ESB runtime server

The ESB designtime server (ESBDT) provides interfaces for all metadata changes from JDeveloper, ant-based import/export or browser-based ESB Control changes.

The ESB runtime server (ESBRT) loads an in-memory cache at startup that contains all service metadata and artifacts such that services run straight from memory.

Async Topic - used for storage of messages that are delivered asynchronously.

Error Topic - will have the messages that could not be delivered due to an error.

Monitor Topic – ESBDT subscribes to this topic to get tracking messages from ESBRT

Control Topic ESB runtime servers listen on the control topic to get notified of any metadata changes

Resub Topic – This topic stores the payload for esb instances where retryable error has occured.

The primary mechanism of interaction between ESBDT and the ESBRT nodes is through

JMS topics. The ESBDT subscribes to both a monitor and error topic to which all ESBRT instances publish their monitoring and error messages. ESBDT then persists that information to the database. The ESBDT also publishes administration messages to a control topic to which all ESBRT instances subscribe.

thats it for today cheers :)

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