<div dir="ltr"><div>I filed <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1553750">Bug 1553750</a> for this telemetry alert which is actually an improvement we have done in <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1542744">Bug 1542744</a>.</div><div>So nothing to be worried about :)<br></div><div class="gmail-field gmail-indent"><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, May 20, 2019 at 5:51 AM <<a href="mailto:telemetry-alerts@mozilla.com">telemetry-alerts@mozilla.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">We have detected a change in the Telemetry probe URLCLASSIFIER_VLPS_CONSTRUCT_TIME in Firefox Nightly builds from 2019-05-16.<br>
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Alert details: <a href="http://alerts.telemetry.mozilla.org/index.html#/detectors/1/metrics/2140/alerts/?from=2019-05-16&to=2019-05-16" rel="noreferrer" target="_blank">http://alerts.telemetry.mozilla.org/index.html#/detectors/1/metrics/2140/alerts/?from=2019-05-16&to=2019-05-16</a><br>
Changes new to Nightly builds on 2019-05-16: <a href="https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9e68d485f7ccea5d8f065fb5f833858e71b4b04a&tochange=786f094a30ae94722246f078561928990ab1e0b7" rel="noreferrer" target="_blank">https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9e68d485f7ccea5d8f065fb5f833858e71b4b04a&tochange=786f094a30ae94722246f078561928990ab1e0b7</a><br>
The value of URLCLASSIFIER_VLPS_CONSTRUCT_TIME over time: <a href="https://telemetry.mozilla.org/new-pipeline/evo.html#!measure=URLCLASSIFIER_VLPS_CONSTRUCT_TIME" rel="noreferrer" target="_blank">https://telemetry.mozilla.org/new-pipeline/evo.html#!measure=URLCLASSIFIER_VLPS_CONSTRUCT_TIME</a><br>
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What to do about this:<br>
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1. File a bug to track your investigation. You can just copy this email into the bug Description to get you started.<br>
2. Reply-All to this email to let the list know that you are investigating. Include the bug number so we can help out.<br>
3. Triage the alert. You can find instructions here: <a href="https://docs.telemetry.mozilla.org/tools/alerts.html#triaging-a-telemetry-alert-email" rel="noreferrer" target="_blank">https://docs.telemetry.mozilla.org/tools/alerts.html#triaging-a-telemetry-alert-email</a><br>
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If you have any problems, please ask for help on the #telemetry IRC channel or on Slack in #fx-metrics. We'll give you a hand.<br>
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What this is:<br>
We have a system called cerberus[1] that compares Telemetry collected on different Nightly builds and looks for sudden changed in value distributions using the Bhattacharyya Distance[2]. It found such a change in URLCLASSIFIER_VLPS_CONSTRUCT_TIME on 2019-05-16 so it asked its buddy medusa[3] to send this email to the dev-telemetry-alerts mailing list and to all email addresses listed in the alert_emails field of URLCLASSIFIER_VLPS_CONSTRUCT_TIME's definition.<br>
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You can do this!<br>
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Your Friendly, Neighbourhood Firefox Telemetry Team<br>
[1]: <a href="https://github.com/mozilla/cerberus" rel="noreferrer" target="_blank">https://github.com/mozilla/cerberus</a><br>
[2]: <a href="https://en.wikipedia.org/wiki/Bhattacharyya_distance" rel="noreferrer" target="_blank">https://en.wikipedia.org/wiki/Bhattacharyya_distance</a><br>
[3]: <a href="https://github.com/mozilla/medusa" rel="noreferrer" target="_blank">https://github.com/mozilla/medusa</a><br>
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