Error (429) - SharePoint Online Throttling

​Error Examples:

The remote server returned an error: (429).

There are other errors associated with throttling or throttling-like behavior:

The server Indicated an exceedance of the request-size limit

(409) Conflict

Version Conflict

Executing CSOM query on sharepoint failed: The operation has timed out Attempt to retry in 5000 ms. # attempt(s) left.

While these errors alone may not necessarily point to throttling, several of them often​​​​​​​ appear with throttling, especially if too many syncs or multiple copies of the same sync running at the same time.

Troubleshooting Steps:

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General Information

• You ,may have too many different connections for different lists all running at the same time
• You may have too many different connections for the same list running the same time

Also see ​How to: Avoid getting throttled or blocked in SharePoint Online​.

User Has Too Many Connections Running at the Same Time to SharePoint

If you have multiple connections running at the same time with the service to the same SharePoint instance, this can flood the servers with too many requests, leading to the throttling errors. ​​The system.log should show all the jobs triggering at once if this is the case.

If this is happening, you need to stagger your jobs and make sure they have an appropriate interval to finish before the next one starts. This can also be controlled with scheduled tasks using the command line to trigger a sync.

​User Has Too Many Connections Running to the Same List

You may have too many multiple syncs that update different parts of the same list. The system.log should show all the jobs triggering at once if this is the case​, and the connections will note the same list in the authentication check details. You MUST stagger the syncs so that one can completely finish before the next one starts so that the updates to the same list don't cause confusion. This can also be controlled with scheduled tasks using the command line to trigger a sync. A description of how a connection can be started via command-line can be found in the user documentation, section "Console Mode".

Hard Throttling​ / (503) Errors

See The Remote Server Returned an Error: (503) Server Unavailable (SharePoint Online)​.

Please note ​How to: Avoid getting throttled or blocked in SharePoint Online​.​​​

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