..
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.. Licensed under the Apache License, Version 2.0 (the "License");
.. you may not use this file except in compliance with the License.
.. You may obtain a copy of the License at
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..     http://www.apache.org/licenses/LICENSE-2.0
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.. _reference-label-tc-ts:
.. |arrow| image:: fwda.png


Traffic Stats
=============
Traffic Stats is a program written in `Golang <http://golang.org>`_ that is used to acquire and store statistics about CDNs controlled by Traffic Control.  Traffic Stats mines metrics from Traffic Monitor's JSON APIs and stores the data in `InfluxDb <http://influxdb.com>`_.  Data is typically stored in InfluxDb on a short-term basis (30 days or less).  The data from InfluxDb is then used to drive graphs created by `Grafana <http://grafana.org>`_ - which are linked to from Traffic Ops - as well as provide data exposed through the Traffic Ops API.  Traffic Stats performs two functions:  first it gathers stat data for Edge Caches and Delivery Services at a configurable interval (10 second default) from the Traffic Monitor API's and stores the data in InfluxDb; second it summarizes all of the stats once a day (around midnight UTC) and creates a daily rollup containing the Max Gbps served and the Total Bytes served.

Stat data is stored in three different databases:

	- cache_stats:  The cache_stats database is used to store data gathered from edge caches.  The `measurements <https://influxdb.com/docs/v0.9/concepts/glossary.html#measurement>`_ stored by cache are: bandwidth, maxKbps, and client_connections (ats.proxy.process.http.current_client_connections).  Cache Data is stored with `tags <https://influxdb.com/docs/v0.9/concepts/glossary.html#tag>`_ for hostname, cachegroup, and CDN.  Data can be queried using tags.


	- deliveryservice_stats:  The deliveryservice_stats database is used to store data for delivery services.  The measurements stored by delivery service are:  kbps, status_4xx, status_5xx, tps_2xx, tps_3xx, tps_4xx, tps_5xx, and tps_total.  Delivery Service stats are stored with tags for cachegroup, CDN, and Deliveryservice xml_id.

	- daily_stats: The daily_stats database is used to store summary data for daily activities.  The stats that are currently summarized are Max Bandwidth and Bytes Served and they are stored by CDN.

------------

Traffic Stats does not influence overall CDN operation, but is required in order to display charts in Traffic Ops and Traffic Portal.