When a service creates a client object (e.g. placementclient) to use another service's API, the call goes through Proxy.request() in the openstacksdk module.  That function calls _report_stats()[1] for every request which calls three other functions for statsd, prometheus and influxdb.  The prometheus function records the number of requests and response times in a dict using the full URL of the request.[2]

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Andrew Ruthven, Wellington, New Zealand
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