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Caching

  • Article

To improve performance, responses can be served from a cache. By default, responses are stored for 2 minutes.

Request

Cache options can be set with the Cache-Control header in the HTTP request, see here for more information.

The API supports the standard max-age, no-cache, and no-store directives.

  • max-age specifies, in seconds, the maximum amount of time a cached response is valid for.
  • no-cache and no-store bypass the response cache and always query the downstream services.

For example, the following request allows a maximum cache age of 30 seconds

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

Response

If a response is returned from the cache, the Age header specifies the staleness of the response in seconds.

For example, the following response is 13 seconds stale.

    HTTP/1.1 200 OK
    Age: 13
    Content-Type: application/json; charset=utf-8
    
    {
        "tables": [
            {
                "name": "PrimaryResult",
                "columns": [
                    {
                        "name": "count_",
                        "type": "long"
                    }
                ],
                "rows": [
                    [
                        1939908516
                    ]
                ]
            }
        ]
    }