Closed Bug 690458 Opened 8 years ago Closed 8 years ago

Rebucket telemetry memory statistics

Categories

(Toolkit :: Telemetry, defect)

defect
Not set

Tracking

()

RESOLVED FIXED
mozilla10

People

(Reporter: justin.lebar+bug, Unassigned)

Details

Attachments

(1 file)

Memory statistics reported by telemetry are too coarse-grained.  For instance, RSS is bucketed in the range [32mb, 1gb] with 10 exponential buckets, so one of the buckets covers roughly the range 530mb to 1gb (*).  This is not particularly useful.

If you have an LDAP account, you can, in theory, see the stats for yourself at [1].  Unfortunately the dashboard is down right now (bug 687117).

Anyway, the solution is rebucketing, which is simple enough.  This will invalidate all of the statistics we'd collected up to this point, but they're not really useful anyway.

(*) I'd look up the actual range, but I can't, because the dashboard is down...

[1] https://metrics.mozilla.com/pentaho/content/pentaho-cdf-dd/Render?solution=metrics&path=telemetry/&file=TelemetryHistogram.wcdf
Attached patch Patch v1Splinter Review
Comment on attachment 563498 [details] [diff] [review]
Patch v1

Do you want to review this one, Taras, or do you want to pass it off to someone working on MemShrink?
Attachment #563498 - Flags: review?(tglek)
Comment on attachment 563498 [details] [diff] [review]
Patch v1

Memshrinkers should do this one
Attachment #563498 - Flags: review?(tglek)
Attachment #563498 - Flags: review?(khuey)
Aha, the telemetry dashboard is back.

I'm not sure exactly how exponential histogram bucketing works.  The RSS bucketing is in fact better than I expected; the top bucket is actually ~680mb, not 530mb.  But the top bucket for explicit covers 440mb - 1gb.

The coarseness of these measurements makes it difficult for us to determine whether changes we've made improve real-world memory usage.
https://hg.mozilla.org/mozilla-central/rev/d21d678255d8
Status: NEW → RESOLVED
Closed: 8 years ago
Resolution: --- → FIXED
Whiteboard: [inbound]
Target Milestone: --- → mozilla10
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