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Summary: SharePoint Online can handle high volumes of actions, but Throttling may occur, limiting simultaneous resource access. It’s rare, usually caused by custom code like REST and CSOM scripts. To avoid Throttling, reduce app requests, call frequencies, and consider using Microsoft Graph API. Employ Retry-After HTTP header and, for migrations, consider using Kernel Migrator for SharePoint.

SharePoint Online is a highly robust application capable of efficiently managing a substantial volume of actions. Even during an ongoing SharePoint Online migration, users can seamlessly utilize available resources and access their data without disruption. However, when access requests reach an elevated threshold, depleting available resources, this scenario is referred to as “Throttling.”

SharePoint employs throttling as a key technique to maintain optimal performance across all its services. Throttling effectively restricts the concurrent number of requests and user actions aimed at accessing resources, ensuring that performance remains at its best.

Experts assert that the occurrence of throttling in SharePoint Online is exceedingly rare, thanks to its impressive track record of delivering over 99% availability and accessibility for all data. Throttling issues typically arise when custom codes, such as REST and CSOM, excessively consume SharePoint Online resources.
SharePoint Online resources

  1. The typical usage is always under the SharePoint limitation, and they never cause or experience Throttling.
  2. Additional services are executed on a regular basis in conjunction with standard operations. These supplementary tasks encompass OneDrive uploads, workflows, and customizations.
  3. The custom scripts that exceed the throttling limit are REST, CSOM and others. While an migration is going on and you are uploading to OneDrive, then you may feel that Microsoft OneDrive has stopped working.

How does SharePoint inform about Throttling?

As soon as the per-user resource usage crosses the throttling limit, SharePoint stops further requests for a shorter period.

  • If a user attempts to access site data or a document within SharePoint Online, the browser will automatically redirect them to a dedicated webpage that provides comprehensive information regarding throttling restrictions.
  • For the custom request calls, SharePoint will return an HTTP error (status code 429 or server too busy-503and).

If the Throttling continues to affect the migration process when you are trying to upgrade SharePoint 2016 to SharePoint 2019, SharePoint will completely stop all the ongoing operations. There will be no more requests and information in Microsoft’s Office 365 Message Center.

How to avoid Throttling issues in SharePoint?

If you find yourself engaged in a migration process, whether it’s transitioning from SharePoint on-premises to SharePoint Online or moving content between two different SharePoint Online tenants, it’s essential to address and mitigate potential throttling issues. Here are some effective remedies to tackle these challenges.

  • Try to minimize the number of apps or operation requests from various users.
  • Reduce the call frequencies.
  • To manage your custom requests, use Microsoft Graph API rather than REST or CSOM.
  • Distribute your website traffic smartly so that a single process does not consume more significant resources.
  • Employ the Retry-After HTTP header.
  • Microsoft Graph APIs offer enhanced scripting capabilities and incorporate the latest advancements in technology. They are also designed to be more efficient in terms of storage and processing resources compared to alternative customer scripting services, resulting in reduced resource consumption and improved performance. Employing Microsoft Graph APIs can significantly decrease the likelihood of throttling.
  • The Retry-After HTTP header proves to be an invaluable tool when dealing with throttling issues. This header ensures that there is a minimum delay in resource requests while the throttling situation is being addressed and resolved.
  • By utilizing the Retry-After HTTP header, SharePoint Online intelligently determines the appropriate time to retry the request automatically. Failing to employ this header may result in unmonitored tasks aggressively submitting requests, leading to excessive consumption of storage and CPU resources.
An automated SharePoint Migration Solution

The throttling issue primarily arises from an ongoing migration process concurrent with multiple other active processes. Microsoft experts recommend initiating the migration when there are no concurrent processes running. Unfortunately, the SharePoint Migration Tool lacks scheduling options for manual migrations, necessitating an immediate start. In situations of throttling, the migration may fail, requiring a restart. To mitigate this, consider exploring Kernel Migrator for SharePoint as an alternative solution.

The software interface offers a comprehensive array of tools to seamlessly connect with SharePoint accounts, whether they are hosted on-premises or in the cloud. Once you’ve refined your data with filters, you can effortlessly generate scheduled jobs tailored to a variety of parameters.
create a scheduling job based on several parameters

You have the flexibility to customize your scheduling preferences, offering options on a Daily, Weekly, Monthly, or One-time basis. For each of these choices, you can specify a start and end date, ensuring that the migration process occurs at a designated time. Furthermore, a descriptive window will appear to provide information when the migration begins, tailored to your chosen schedule.

Final Words

One cannot avoid Throttling in SharePoint. Instead, one can use the existing resources without breaking the Throttling limits. This is applicable for SharePoint migrations too.

For a seamless and successful migration experience, consider utilizing Kernel Migrator for SharePoint software. With this powerful tool, you can conveniently schedule your data transfer to ensure it complies with throttling limits, making your migration process more efficient and effective.

Kernel Migrator for SharePoint