Acrolinx

Author: Julia Shimanskiy

articles/virtual-machine-scale-sets/spot-priority-mix.md

@@ -16,7 +16,7 @@ ms.custom: engagement-fy23
 
 **Applies to:** :heavy_check_mark: Flexible scale sets 
 
-Azure allows you to have the flexibility of running a mix of uninterruptible regular VMs and interruptible Spot VMs for Virtual Machine Scale Set deployments. You're able to deploy this Spot Priority Mix using Flexible orchestration to easily balance between high-capacity availability and lower infrastructure costs according to your workload requirements. This feature allows you to easily manage your scale set capability to achieve the following:
+Azure allows you to have the flexibility of running a mix of uninterruptible regular VMs and interruptible Spot VMs for Virtual Machine Scale Set deployments. You're able to deploy this Spot Priority Mix using Flexible orchestration to easily balance between high-capacity availability and lower infrastructure costs according to your workload requirements. This feature allows you to easily manage your scale set capability to achieve the following goals:
 
 - Reduce compute infrastructure costs by applying the deep discounts of Spot VMs
 - Maintain capacity availability through uninterruptible regular VMs in the scale set deployment
@@ -39,14 +39,14 @@ You can set your Spot Priority Mix by using a template to add the following prop
 ```
 
 **Parameters:**
-- `baseRegularPriorityCount` – Specifies a base number of VMs that will be *Regular* priority; if the Scale Set capacity is at or below this number, all VMs will be *Regular* priority.
-- `regularPriorityPercentageAboveBase` – Specifies the percentage split of *Regular* and *Spot* priority VMs that will be used when the Scale Set capacity is above the *baseRegularPriorityCount*.
+- `baseRegularPriorityCount` – Specifies a base number of VMs that are *Regular* priority; if the Scale Set capacity is at or below this number, all VMs are *Regular* priority.
+- `regularPriorityPercentageAboveBase` – Specifies the percentage split of *Regular* and *Spot* priority VMs that are used when the Scale Set capacity is above the *baseRegularPriorityCount*.
 
 You can refer to this [ARM template example](https://paste.microsoft.com/f84d2f83-f6bf-4d24-aa03-175b0c43da32) for more context.
 
 ### [Portal](#tab/portal-1) 
 
-You can set your Spot Priority Mix in the Scaling tab of the Virtual Machine Scale Sets creation process in the Azure portal. The following steps will instruct you on how to access this feature during that process. 
+You can set your Spot Priority Mix in the Scaling tab of the Virtual Machine Scale Sets creation process in the Azure portal. The following steps instruct you on how to access this feature during that process. 
 
 1. Log in to the [Azure portal](https://portal.azure.com).
 1. In the search bar, search for and select **Virtual Machine Scale Sets**.
@@ -113,12 +113,12 @@ Some important terminology to notice before referring to these examples:
 The following scenario assumptions apply to this example:
 - **sku.capacity** is variable, as the autoscaler will add or remove VMs from the scale set
 - **Base (standard) VMs:** 10
-- **Additional Regular priority VMs:** 0
+- **Extra standard VMs:** 0
 - **Spot priority VMs:** 0
 - **regularPriorityPercentageAboveBase:** 50%
 - **Eviction policy:** Delete
 
-| Action | sku.capacity | Base (standard) VMs | Additional Regular priority VMs | Spot priority VMs |
+| Action | sku.capacity | Base (standard) VMs | Extra standard VMs | Spot priority VMs |
 |---|---|---|---|---|
 | Create | 10 | 10 | 0 | 0 |
 | Scale out | 20 | 10 | 5 | 5 |
@@ -133,24 +133,24 @@ The following scenario assumptions apply to this example:
 
 Example walk-through:
 1. You start out with a Virtual Machine Scale Set with 10 VMs.
-    - The `sku.capacity` is variable and doesn't set a starting number of VMs. The Base VMs is set at 10, thus your total starting VMs is just 10 Base (standard) VMs.
-1. You then scale out 5 times, with 50% Regular priority VMs and 50% Spot VMs.
-    - Note, because there's a 50/50 split, in the fourth scale out, there is one more Spot VM than Regular priority. Once it's scaled out again (5th scale out), the 50/50 balance is restored with another Regular priority VM.
-1. You then scale in your scale set with the eviction policy being delete. This will delete all the Spot VMs.
-1. With the scale out operations mention in this scenario, you will restore the 50/50 balance in your scale set by only creating Spot VMs.
-1. By the last scale out, your scale set is already balanced, so one of each type of VM will be created. 
+    - The `sku.capacity` is variable and doesn't set a starting number of VMs. The Base VMs are set at 10, thus your total starting VMs are just 10 Base (standard) VMs.
+1. You then scale-out 5 times, with 50% standard VMs and 50% Spot VMs.
+    - Note, because there's a 50/50 split, in the fourth scale-out, there's one more Spot VM than standard VM. Once it's scaled out again (5th scale-out), the 50/50 balance is restored with another standard VM.
+1. You then scale in your scale set with the eviction policy being delete, which deletes all the Spot VMs.
+1. With the scale-out operations mentioned in this scenario, you restore the 50/50 balance in your scale set by only creating Spot VMs.
+1. By the last scale-out, your scale set is already balanced, so one of each type of VM is created. 
 
 ### Scenario 2
 
 The following scenario assumptions apply to this example:
 - **sku.capacity** is variable, defined by autoscaler; starting with 20
 - **Base (standard) VMs:** 10
-- **Additional Regular priority VMs:** 2
+- **Extra standard VMs:** 2
 - **Spot priority VMs:** 8
 - **regularPriorityPercentageAboveBase:** 25%
 - **Eviction policy:** Deallocate
 
-| Action | sku.capacity | Base (standard) VMs | Additional Regular priority VMs | Spot priority VMs |
+| Action | sku.capacity | Base (standard) VMs | Extra standard VMs | Spot priority VMs |
 |---|---|---|---|---|
 | Create | 20 | 10 | 2 | 8 |
 | Scale out | 50 | 10 | 10 | 30 |
@@ -160,15 +160,15 @@ The following scenario assumptions apply to this example:
 
 Example walk-through:
 1. With the initial creation of the Virtual Machine Scale Set and Spot Priority Mix, you have 20 VMs.
-    - 10 of those VMs are the Base (standard) VMs, 2 Additional Regular priority VMs, and 8 Spot priority VMs for your 25% *regularPriorityPercentageAboveBase*. 
-    - Another way to look at this is you have 1 Regular priority VM for every 4 Spot VMs in the scale set. 
-1. You then scale out twice to create 90 more VMs; 23 Regular priority VMs and 67 Spot VMs.
+    - 10 of those VMs are the Base (standard) VMs, 2 extra standard VMs, and 8 Spot priority VMs for your 25% *regularPriorityPercentageAboveBase*. 
+    - Another way to look at this ratio is you have 1 standard VM for every 4 Spot VMs in the scale set. 
+1. You then scale-out twice to create 90 more VMs; 23 standard VMs and 67 Spot VMs.
 1. When you scale in by 10 VMs, 10 Spot VMs are *stop-deallocated*, creating an imbalance in your scale set.
-1. Your next scale out operation creates another 2 Regular priority VMs and 8 Spot VMs, bringing you closer to your 25% above base ratio.
+1. Your next scale-out operation creates another 2 standard VMs and 8 Spot VMs, bringing you closer to your 25% above base ratio.
 
 ## Troubleshooting 
 
-There is only one error that is specific to Spot Priority Mix. To avoid it, be sure to configure the `priorityMixPolicy` to specify a *Spot* priority in the `virtualMachineProfile`. All other potential errors are either the normal Virtual Machine Scale Set, Spot, or Autoscale errors.
+There's only one error that is specific to Spot Priority Mix. To avoid it, be sure to configure the `priorityMixPolicy` to specify a *Spot* priority in the `virtualMachineProfile`. All other potential errors are either the normal Virtual Machine Scale Set, Spot, or Autoscale errors.
 
 ## Next steps