Setting Change: Provisioning Concurrency Mode (Adaptive or Fixed)

Provisioning Concurrency Mode: Adaptive builds more session hosts at once while Azure has room and slows down when it throttles; Fixed keeps a set number.

Before you begin

  • A Super Administrator or platform operator, to decide in Review settings or to change the Global value
  • Tenant administrators can still set the mode for their own tenant or host pool in the Configuration Matrix

What changes if you choose Adaptive

With Fixed, an Add VMs batch keeps exactly Provisioning Concurrency builds running (3 by default, up to 20). With Adaptive, the batch starts at that same number and then:

  • Adds one more build at a time while your subscription's Azure write budget is healthy and nothing is throttled
  • Holds steady when the write budget is getting low
  • Halves the number of builds when Azure throttles, then waits before speeding up again
  • Never cancels a build that is already running. It just waits for one to finish before starting the next
  • Stops at a ceiling sized from the App Service plan Atlas runs on (its CPU cores and memory), at most 50 VMs at once and never below your Provisioning Concurrency

Why it matters

A fixed number has to be low enough for the busiest moment, so it is usually far below what a subscription can take. At 3 VMs at once, a 500-host rollout takes about a day. Adaptive reads what Azure reports on every change, so the same rollout finishes in a few hours without pushing the subscription into throttling.

Before you switch

  • Regional vCPU quota still applies. A faster rollout reaches the quota limit sooner, so check Adaptive Quota™ first
  • Each build also uses a domain join or Intune enrollment and a Run Command session, which have their own limits
  • If you run Atlas on a small App Service plan, Adaptive keeps the ceiling low on its own (at least 4 VMs at once)

Not sure? Keep Fixed at Global and set Adaptive on one large host pool in the Configuration Matrix. Watch its next Add VMs batch, then decide for the rest.

How to decide

  1. Open Settings → Matrix. If the update left settings for you to review, the Review settings page opens on its own (or follow the banner at the top of the app).
  2. Under Provisioning Concurrency Mode, choose Keep current behavior to stay on Fixed, or Use the new default to switch to Adaptive.
  3. Click Save decisions. The choice is saved at Global, so every tenant and host pool that inherits picks it up. Tenants and pools with their own value keep it.

You can change your mind later: edit Provisioning Concurrency Mode in the Global column of the Configuration Matrix. New deployments start on Adaptive.

Next steps