Communications between apps

Inter app communications

Http

REST

Contents

• XML

• Json

GraphQL

Webservice/SOAP

• Envelopes

Files

FTP/SFTP

Database

Messaging

• jms

  • https://dzone.com/articles/java-message-service-jms

• Hessian

how it gets the data

• pulling from the app/intermediary(message broker)

  • Making a request

    • on demand

    • scheduled (quartz)

  • https://en.wikipedia.org/wiki/Pull_technology

• Pushed from app/intermediary(message broker)

  • subscribed to it and when updates occurs (ie to database or event or in flow) it will send a request to who needs it

    • Can do this on a schdule

    • if receiving app is down, then it will not lose the request as it will still be on message broker. So when back up it can start to get these messages/data and process them. This prevents lost messages/data.

      • If app has high availability (ie via kubernetes), then can expect all messages to be sent and received, without losing any. Thus can rely on http as a means to communciate.

  • https://en.wikipedia.org/wiki/Publish%E2%80%93subscribe_pattern

  • observer pattern

• Sockets

sync or async

• request - response

• async req-response

• fire and forget

• publish subscribe

• message routing

-3 Message Exchange Patterns in Application Integration To Know About

Intra app communications

• Sending messages to objects

  • Delegating to dependencies