How to monitor partition count currently in use for event hub namespaces?

Hi @Sander van de Velde | MVP

Our concern is that we have hundreds of event hubs in our dozens of event hub namespaces with more being onboarded every day in many different environments. They all have differing amounts of partitions being used so it's very hard to keep track of how many total partitions in the namespace have been used. We would like to be notified when the total number of partitions in use for an event hub namespace has reached 80% or so. This way we can avoid running into any allocation issues in the future.

Thanks for your response!

Hi @Sander van de Velde | MVP

Just to confirm, there's no metric for number of partitions currently in use for an entire event hub namespace? For example, our premium tier event hub has 16 PU which would allocate 3200 partitions to it (16 PU * 200 = 3200). Our concern is that we have dozens and dozens of event hub namespaces with hundreds of entities in each namespace. It's very hard for us to keep track of the number of partitions being used and we would like to monitor and notify us when 80% or so of those 3200 partitions are used up. So if there's no metric then we'd like to use logs to do that but from what I've seen the event hub logs don't provide that information either.

Thanks for your response!

Hello @Aaron Turcott ,

I see, I was not expecting you used a eventhub namespace with a dynamic amount of partitions.

You are limited to the amount of partitions used by alle eventhubs in a namespace because it is related to the number of processing units due to the used of the premium tier:

I tried the CLI on an eventhub:

az eventhubs namespace show --resource-group iot-enrich-test-rg --name iot-enrich-test-ehns

This does not return the maximum amount of partition but it gives me the tier and capacity units:

...
  "sku": {
    "capacity": 1,
    "name": "Standard",
    "tier": "Standard"
  }, 
...

From here, I could calculate the maximum number of partitions.

I can see that a maximum of 32 partitions us supported from the documentation diagram.

I can also see the number of partitions in use:

az eventhubs eventhub list --namespace-name  iot-enrich-test-ehns --resource-group iot-enrich-test-rg 

This returns a list of eventhubs in the namespace, each with the number of partitions:

...
    "name": "enricheh",
    "partitionCount": 4,
    "partitionIds": [
      "0",
      "1",
      "2",
      "3"
    ],
...
    "name": "testeh",
    "partitionCount": 1,
    "partitionIds": [
      "0"
    ],
...

I expect these two number must be added, then four plus one makes five.

So, I know this eventhub namespace has used 5 partitions out of the 32 at this moment.

Could this work for you?

Thinking out of the box, I expect you also use Bicep regarding the resource creation.Changes to resources then are updated by Bicep changes?

Then you could check the Bicep for the same settings.

Can this work for you too?

@Sander van de Velde | MVP we looked at using the az cli for this but don't have a way of alerting with it. If Azure doesn't provide a native solution for notifying us when 3000 of 3200 partitions are used for an event hub namespace then we'll have to figure out a workaround. Thank you so much for your help though!

Hello, I don't have a query yet because Azure doesn't let me query event hub topics to find out how many partitions they are currently using. Here I tried querying from just the event hub topics that are hosted in an event hub namespace using the type = microsoft.eventhub/namespaces/eventhubs. I found that type from the event hub topic in the Azure portal. It doesn't seem that I am able to query this information.

I see, we have to implement a custom solution. I will update you tomorrow. After my simulation repo