App Services in Microsoft Azure : Logic Apps

Azure offers a set of PAAS(Platform-As-A-Service) offerings known as App Services. Logic Apps are one of the services under the App Services Category. They are similar to workflows and can be used to perform a set of connected operations. Here is an example of a logic app :

Let us say there are a set of tables on two different database servers and you are trying to replicate data from one server to the other. Your goal is to monitor the destination tables and perform two specific actions when new data comes in :

• Call a stored proc that processes the new data and returns a result set.
• Invoke an API and pass the result set from the previous step.

Within a few minutes, you can create a logic app which can be scheduled to run at specified intervals. This logic app will have two connected nodes. The first one calls a stored procedure that queries the destination tables for new data and does some business rules processing and returns a result set and the second node can then take this result set and pass it to an API.

We can also scale up (i.e. increase the processing power) or scale out (increase the number of instances) very easily via the Azure portal. We do have to deal with any concurrency issues that may arise when several instances of the logic app are running simultaneously.