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diff --git a/web/api/queries/ses/README.md b/web/api/queries/ses/README.md deleted file mode 100644 index a06f646ef..000000000 --- a/web/api/queries/ses/README.md +++ /dev/null @@ -1,65 +0,0 @@ -<!-- -title: "Single (or Simple) Exponential Smoothing (`ses`)" -sidebar_label: "Single (or Simple) Exponential Smoothing (`ses`)" -custom_edit_url: https://github.com/netdata/netdata/edit/master/web/api/queries/ses/README.md -learn_status: "Published" -learn_topic_type: "References" -learn_rel_path: "Developers/Web/Api/Queries" ---> - -# Single (or Simple) Exponential Smoothing (`ses`) - -> This query is also available as `ema` and `ewma`. - -An exponential moving average (`ema`), also known as an exponentially weighted moving average (`ewma`) -is a first-order infinite impulse response filter that applies weighting factors which decrease -exponentially. The weighting for each older datum decreases exponentially, never reaching zero. - -In simple terms, this is like an average value, but more recent values are given more weight. - -Netdata automatically adjusts the weight (`alpha`) based on the number of values processed, -using the formula: - -``` -window = max(number of values, 15) -alpha = 2 / (window + 1) -``` - -You can change the fixed value `15` by setting in `netdata.conf`: - -``` -[web] - ses max window = 15 -``` - -## how to use - -Use it in alerts like this: - -``` - alarm: my_alert - on: my_chart -lookup: ses -1m unaligned of my_dimension - warn: $this > 1000 -``` - -`ses` does not change the units. For example, if the chart units is `requests/sec`, the exponential -moving average will be again expressed in the same units. - -It can also be used in APIs and badges as `&group=ses` in the URL. - -## Examples - -Examining last 1 minute `successful` web server responses: - -- ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=min&after=-60&label=min) -- ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=average&after=-60&label=average&value_color=yellow) -- ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=ses&after=-60&label=single+exponential+smoothing&value_color=orange) -- ![](https://registry.my-netdata.io/api/v1/badge.svg?chart=web_log_nginx.response_statuses&options=unaligned&dimensions=success&group=max&after=-60&label=max) - -## References - -- <https://en.wikipedia.org/wiki/Moving_average#exponential-moving-average> -- <https://en.wikipedia.org/wiki/Exponential_smoothing>. - - |