Throttling is a key factor that can affect the speed of your Microsoft 365 migration. While CloudM Migrate is designed to handle throttling that occurs during a migration, the most effective strategy is to proactively manage it before your project begins. See Strategies for Optimizing Migration Performance.
This article explains the throttling policies for services like Exchange and SharePoint and provides clear, actionable steps to help you mitigate them for a more efficient migration.
Understanding Microsoft 365 Throttling
Microsoft 365 applies throttling to ensure service performance and stability for all users in a shared environment. It's a protective measure that limits the number of requests an application (like CloudM Migrate) can make.
Throttling policies differ between Microsoft services. This article covers the most relevant ones for migration:
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Exchange Online: Primarily governed by EWS Throttling (which can be temporarily disabled) and Service Protection Throttling (a permanent layer).
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SharePoint Online: Governed by its own set of policies that limit concurrent requests and operations per second. Unlike EWS throttling, these cannot be disabled.
While CloudM Migrate is designed with an adaptive architecture to manage throttling automatically, disabling EWS throttling is a crucial first step for maximizing migration throughput from/to Microsoft Exchange Online.
How to Handle Throttling
Exchange Online Throttling
Microsoft now allows administrators to temporarily disable EWS throttling directly from the Microsoft 365 admin center. This is a highly recommended step to perform before beginning your migration.
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Log in to the Microsoft 365 admin center with your administrator credentials.
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Navigate to Support > New service request.
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In the search field, search for
Increase EWS Throttling Policyand press Enter. -
Click Run Tests and allow the diagnostic to complete.
- If the automated diagnostic test is unavailable, you may need to create a new service request and ask a Microsoft engineer to temporarily disable the policy for you.
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Select a duration for the policy to be disabled (e.g., 30, 60, or 90 days).
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Acknowledge the change by checking the box and click Update Settings.
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The update will be initiated and should be completed within 15 minutes. We recommend re-running the test after 15 minutes to verify that the policy is disabled.
SharePoint Online Throttling
SharePoint Online has its own throttling policies that protect the service from overuse. Unlike Exchange, SharePoint policies cannot be disabled. The best way to handle SharePoint throttling is to use the most efficient API available for the job.
Utilize the SharePoint Migration API: The SharePoint Migration API provides a direct, high-speed connection for migrating file data to SharePoint Online and OneDrive. This API is specifically designed to handle large data volumes and bypasses many of the standard API throttling limits, making it the most efficient method for these migrations. You can enable it in CloudM Migrate for the source and/or destination Microsoft 365 tenant. See Migrating to or from Microsoft 365 using the SharePoint Migration API for more information.
Performance Tuning & Best Practices
To further optimize your migration performance on the Microsoft platform, consider the following best practices:
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Use Azure Servers: Hosting the CloudM Migrate application within Microsoft's own Azure environment is highly recommended. Because the application resides within the same network as the Microsoft 365 tenant, this can significantly improve data transfer speeds by reducing latency and ensuring a high-throughput network connection.
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Distribute workloads: To manage the number of concurrent connections and data requests, you can distribute your SharePoint migration across multiple CloudM Migrate configurations using separate, dedicated Azure AD Application registrations. This provides a new, independent identity for CloudM Migrate, effectively giving you a new set of API allowances and allowing you to bypass throttling limits.