Can Azure EventHub be used for critical transactional data in production?

Question

Reading the documentation, Azure EventHubs is meant for:

1. Application instrumentation
2. User experience or workflow processing
3. Internet of Things (IoT) scenarios

Can this be used for any transactional data, handling revenue or application sensitive data?

Based on what I read, looks like it is meant for handling data that one should not be worried about any data loss. Is this the case?

Answer 1

It is mainly designed for large scale ingestion of data. That is why typical scenario's include IoT solutions which consists of a multitude of devices sending mass amounts of telemetry data.

To allow for this kind of scale it does not include some features other messaging service, like Azure Service Bus, do have. I think this blog does a good job of listening the differences. Especially the section Use Case explains things very well:

From a target use case perspective if we consider some of our typical enterprise integration patterns then if you are implementing a pattern which uses a Command Message, or a Request/Reply Message then you probably want to use Azure Service Bus Messaging.  RPC patterns can be implemented using Request/Reply messages on Azure Service Bus using a response queue.  These are really about ESB and EAI style messaging patterns where you want to send messages between applications and probably want to use other features such as property based routing.

Azure Event Hubs is more likely to be used if you’re implementing patterns with Event Messages and you want somewhere reliable to send them that is capable of dealing with a massive scale but will allow you to do stuff with the events out of process.

With these core target use cases in mind it is easy to see where the scale differences come into play.  For messaging it’s about one application telling one or more apps to DO SOMETHING or GIVE ME SOMETHING.  The alternative is that in eventing the applications are saying SOMETHING HAS HAPPENED.  When you consider this in typical application scenarios and you put events into the telemetry and logging space you can quickly see that the SOMETHING HAS HAPPENED scenario will produce a lot more traffic than the other.

Now I’m not saying that you can’t implement some messaging type functions using event hubs and that you can’t push events to a Service Bus topic as in integration there are always different requirements which result in different implementation scenarios, but I think if you follow the above as a general rule then you will usually be on the right path.

That does not mean however, that it is only capable of handling data that one should not be worried about any data loss. Data is stored for a configurable amount of time and if necessary, this data can be read from an earlier point in time.

Now, given your scenario I do not think Event Hub is the best fit. But truth to be told, I am not sure because you will have to elaborate more on what you want to do exactly.

Addition The idea behind Event Hubs is that you will get at least once delivery at great scale. (Source). See also this question: Does Azure Event Hub guarantees at least once delivery?