Part 6: BizTalk Migration: Correlation in logic app
Correlation is a frequently used approach in BizTalk to manage interface where the downstream system takes non-deterministic time to process messages and respond back. BizTalk provides correlation configuration as part of Orchestration and many things are managed in the background using the MessageBox SQL database. But the key point is we have promoted property that is matched for incoming message and waiting for orchestration, to link correlated message.
How to achieve this in LogicApp where there is no MessageBox SQL database?
We can use Blob storage to solve this as described below:
Step1: LA01 — Before sending messages to downstream we will send a message to BobStorage — Container( specific for the logic app) with a name that contains value as correlated id corr01.json
Step2: Send a message to downstream for processing and complete logic app LA01 instance.
Step3:LA02 ( blob triggered or HTTP triggered ) as part of response processing from Downstream.
Step4: LA02 extracts correlated id from the response message and uses that value to find the message/blob [corr01.json] in blob storage.
Step5: LA02 Delete correlate message/blob from blob storage
Thus we are able to achieve correlation without using MessageBox Database
Functionally integration requirements and scenario will remain the same we just need to find how to implement those in new technology platforms…