I am using below code receive the events from Azure Event-Hub
I want to Handle the requests coming to event-hub Sequentially. For example someone sent 5 events in very quick time, I want to complete request 1 processing then i want take the second request to process.
How can i handle the events coming to event-hub Sequentially?
Event Hub uses partitions to enable horizontal scaling of event processing. You can specify number of partitions during the event hub creation from 1 to 32. Message order is guaranteed only within a partition but not across all partitions.
If you need the order to be maintained, you need to write events only to a specific partition and read only from the same partition. In Azure Event Hub, partitions are distributed across different instances for high availability. Which means, a partition may go offline for maintenance and come online later. So if you wanted to manage order, you need to write and read to a single partition and you may need to manually manage situations such as partition go offline from your application logic.
If you need to manage order, I would recommend using Azure Service Bus queue which order & availability is managed by Service bus it self.
From the docs,
In order to make it sequential you need to select the proper partitionKey
If you don't specify a partition key when publishing an event, a round-robin assignment is used. In many cases, using a partition key is a good choice if event ordering is important. When you use a partition key, these partitions require availability on a single node, and outages can occur over time; for example, when compute nodes reboot and patch.
