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Performance/Metrics

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< Performance
Revision as of 22:27, 10 January 2019 by imported>Krinkle
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This page documents metrics from Performance Team services. Currently in Graphite.

Deployment and monitoring

See Performance/Runbook/Webperf services for the internal details of these services, such as where the metrics originate, and how they are processed/aggregated.

navtiming-2 metrics

The navtiming-2 metrics are available in Graphite under the frontend.navtiming2 prefix.

Difference with navtiming-1

Notable differences:

  • Offsets are computed relative to fetchStart instead of navigationStart.
  • We no longer filter out zero values.
  • The sanity filter no longer has an upper bound.
  • When the sanity filter encounters negative numbers, it rejects the entire event instead of just the individual data point.

See phab:T104902 for more information about why the metrics were redefined.

Offsets

  • responseStart: From PerformanceTiming, relative to fetchStart.
  • firstPaint: (non-standard)
  • domInteractive: From PerformanceTiming, relative to fetchStart.
  • domComplete: From PerformanceTiming, relative to fetchStart.
  • loadEventStart: From PerformanceTiming, relative to fetchStart.
  • loadEventEnd: From PerformanceTiming, relative to fetchStart. Also known as "Page load end" or "Total page load time". This typically corresponds with the browser's native page loading indicator.

Deltas

  • dns: Computed client-side from PerformanceTiming domainLookupEnd - domainLookupStart. (Transmitted as "dnsLookup")
  • unload: Computed client-side from PerformanceTiming unloadEventEnd - unloadEventStart.
  • redirect: Computed client-side from PerformanceTiming redirectEnd - redirectStart. (Transmitted as "redirecting").
  • mediaWikiLoad: Computed client-side based on custom mwLoadEnd and mwLoadStart measures. (Transmitted as "mediaWikiLoadComplete").
  • tcp: Computed server-side as connectEnd - connectStart. This includes SSL negotiation.
  • request: Computed server-side as responseStart - requestStart.
  • response: Computed server-side as responseEnd - responseStart.
  • processing: Computed server-side as domComplete - responseEnd.
  • onLoad: Computed server-side as loadEventEnd - loadEventStart.
  • ssl: Computed server-side as connectEnd - secureConnectionStart. This is a subset of tcp.

SaveTiming metrics

SaveTiming get reported to mw.performance.save in statsd. To see if it's running properly, the mw.performance.save.sample_rate key should have hits.

See also