SOLACE REDELIVERY DELAYER

Overview

The purpose of this microservice is to implement an exponential backoff from a Solace DMQ back to the original queue.

Getting started quickly

1. Edit src/main/resource/application.properties with values for your environment.

2. Ensure that your configured SOURCE_QUEUE has a maximum redelivery configured:

3. Then run mvn spring-boot:run

You should see the following message:

c.s.j.protocol.impl.TcpClientChannel     : Client-1: Connecting to host 'orig=tcp:solacehost:port, scheme=tcp:, host=solacehost, port=port' (host 1 of 1, smfclient 1, attempt 1 of 1, this_host_attempt: 1 of 1)
c.s.jcsmp.impl.JCSMPBasicSession         : Client-1: AdCtrl version changes: 2->4
c.s.j.protocol.impl.TcpClientChannel     : Client-1: Connected to host 'orig=tcp:solacehost:port, scheme=tcp:, host=solacehost, port=port' (smfclient 1)
c.s.r.api.ISolaceMessagingService        : Starting consumer on #DMQ

Documentation

If a consumer fails to process a message, it is immediately sent back to the queue and re-delivered back to the consumer. This could potentially result in a DoS-like attack against the endpoint. Perhaps you want to retry processing a message after a certain interval, have an exponential backoff in case of further failures and have a threshold after which you will stop processing messages all together.

The diagram above describes the flow of this application. You will have a SOURCE_QUEUE, a DMQ (for the SOURCE_QUEUE) and an optional ERROR_QUEUE.

1. A message on the SOURCE_QUEUE can be redelivered N number of times before it is expired to the DMQ
2. The redelivery delayer microservice listens to the DMQ and injects a configurable header that counts the number of times it has been sent for reprocessing. It will use a configurable exponential backoff factor before send it back to the SOURCE_QUEUE
3. If the message exceeds the threshold of the MAXIMUM delay, the microservice will either discard the message or send it to an optionally configured ERROR_QUEUE for processing

Resources

For more information try these resources:

• The Solace Developer Portal website at: https://solace.dev
• Ask the Solace Community

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Authors

See the list of contributors who participated in this project.

License

See the LICENSE file for details.