Query execution times can vary widely based on:

  • The complexity of the query.
  • The amount of data being analyzed.
  • The load on the system at the time of the query.
  • The load on the workspace at the time of the query.

You might want to customize the timeout for the query. The default timeout is 3 minutes. The maximum timeout is 10 minutes.

Timeout request header

To set the timeout, use the Prefer header in the HTTP request by using the standard wait preference. For more information, see this website. The Prefer header puts an upper limit, in seconds, on how long the client waits for the service to process the query.


If a query takes longer than the specified timeout (or default timeout, if unspecified), it fails with a status code of 504 Gateway Timeout.

For example, the following request allows a maximum server timeout age of 30 seconds:

    POST https://api.loganalytics.azure.com/v1/workspaces/{workspace-id}/query
    Authorization: Bearer <access token>
    Prefer: wait=30
        "query" : "Heartbeat | count"