Using Azure Container App Jobs as a substitute for AWS Fargate tasks: what's the max concurrent execution limit?

Question

Hello,

I am using Azure Container App Jobs in an effort to migrate off of AWS Fargate tasks. One question I am trying to determine is how scaling works. The way I've currently configured this is to have a single Container App Job and simply launch multiple executions (often concurrently).

With Fargate I often have 100-1,000 tasks running concurrently. Can Azure Container App Job executions handle a similar load?

I see that the workload profile (I believe it's the consumption profile), maxes the available CPU + RAM to 4 CPUs / 8gb of RAM. Is that per execution? Or is this a global limit? Meaning if I try to run 10 executions all requesting 2 CPU / 4gb of RAM, I'll be limited to 2 concurrent executions? From my testing so far that doesn't seem like the case.

Additionally, how many executions can I launch concurrently? Reading online it seems there is no hard cap set by Azure, but the amount of resources available can be a limiting factor. With Fargate I was able to simply increase the quota by submitting a support ticket.

Any guidance on how to handle this would be greatly appreciated. Thanks!

Answer 1

Hello Hassan Syyid •,

Azure Container Apps Jobs are a good match for running ephemeral, on-demand container workloads, similar to AWS Fargate tasks. You're on the right track using them to replace Fargate.

Here's how concurrency and resource limits work:

1.Per-Execution Resource Limits: The limit of 4 vCPU / 8 GiB RAM in Consumption workload profile is per job execution, not global.

• So, if you run 10 job executions each requesting 2 vCPU / 4 GiB RAM:
• You can run them concurrently, provided Azure has the capacity in your region.
• This limit does not cap total resource usage across executions — it’s a per-execution container spec limit.

2. Concurrency (Parallel Executions)

Azure does not enforce a fixed hard cap on concurrent job executions.

However:

• There may be soft regional quotas (e.g., total concurrent cores, memory, number of jobs).
• If you hit a limit, Azure will queue executions or throw an error depending on the cause.
• You can request quota increases through Azure Support — similar to how you did with AWS Fargate.

3.Scaling Behavior

• Azure Container App Jobs scale independently per execution — unlike apps, jobs don’t scale replicas automatically.
• You trigger one job execution at a time, and each becomes a new container instance.
• Azure manages provisioning, so you can run many jobs in parallel, assuming no quota/resource block

4.Best Practices for Large Concurrency

• To safely run 100–1000 concurrent executions:
• Use Consumption or Dedicated (Premium) plans based on performance needs.
• Review your subscription quota limits in Azure (CPU, memory, job executions).
• Pre-test for your target scale and monitor for any rate-limiting, throttling, or capacity delays.
• If needed, file a quota increase request via Azure Portal:
• Azure Portal → Help + support → Create a support request → Quotas → Container Apps.

For your reference, please follow the below documentation:

Azure Container Apps Jobs - Overview

Workload Profiles and Limits

Azure Quotas for Container Apps

Hope this helps!