Understand Azure polling limits

The SolarWinds Platform sends API requests to Azure to monitor Azure VMs managed as nodes in the SolarWinds Platform, cloud services, and cloud applications. For example, SAM includes predefined Azure templates that you can assign to nodes to pull metrics for Azure Blob storage accounts and event hub namespaces. Requests may also be consumed by third-party products and custom code in your environment.

Azure has a polling limit of 1 million free API requests per subscription per calendar month and considers a single API request (also known as a "call") to be one that returns 1,440 data points.

• If an API request returns more than 1,440 data points, Azure counts it as multiple API requests.
• If an API request returns less than 1,440 data points, Azure counts as less than one API request.

Azure constantly checks incoming requests against account limit settings. To calculate the number of API requests per day, Azure aggregates the number of data points consumed each day and divides that total by 1,440 — the total number of data points that can be stored per metric per day. To learn about increasing polling limits, review Azure subscription and service limits from Microsoft.

Azure applies throttling after reaching 12,000 read-requests per hour, by default.

To manage polling to avoid exceeding limits and incurring charges, you can:

• Edit cloud account properties to toggle monitoring on and off for an entire cloud account or individual VMs.
• Ensure that the Azure Resource Polling Frequency is the same or less frequent than the granularity of data provided by Microsoft. As of February 2020, Azure provides statistics in 5 minutes intervals. Each poll uses a request and if you poll the statistics more frequently, you get the same information multiple times.
• Configure polling alerts for throttling, exceeded limits, health status, and more.
• Request a limit increase from Microsoft.
• Disable the Azure Monitor API.
• Proactively track Azure resource usage, as described next.

To consolidate Azure payments into a single bill, download the free Cost Calculator for Azure.

Track Azure resource usage

There are many ways to track Azure usage and proactively adjust capacity before exceeding limits and incurring charges, including:

• Log into the Azure Portal and display usage statistics.
• Download a usage file from the Azure Portal.

To display approximate usage in the SolarWinds Platform Web Console

1. On the Cloud Summary page, click Cloud Infrastructure Monitoring.

2. On the Cloud Infrastructure Monitoring, click Manage Cloud Accounts.

3. On the Manage Cloud Accounts and select the check box for an Azure account.

4. Click Edit Properties.

5. On the Edit Properties page, switch to the API Polling Options tab and examine the Approximate Requests Used this Month value.

   The SolarWinds Platform measures requests initiated by your Orion deployment. The number covers requests by all accounts in your subscription.

Disable the Azure Monitor API

You can disable the Azure Monitor API at the account level to avoid exceeding polling limits and incurring fees, especially if levels get close to or exceed the limit of free requests. Azure APIs continue polling for VM status, as displayed on the Cloud Summary and Instance Details pages, but metric polling stops.