Jul 11

Telemetry Status

Telemetry Present

Telemetry infrastructure has only been deployed for week, but we are already gathering interesting data:

  • Memory usage from about:memory gives us an idea of what constitutes typical memory usage for Firefox
  • Cycle-collection overhead, stats tell us about browser pauses due to memory cleanup
  • Detailed startup profiling tells us whether our new library preloading logic is effective
  • Info on whether the browser was shutdown correctly will help us diagnose shutdown problems
  • Plugin enumeration timing to make sure my faster plugin enumeration stays fast
  • HTTP connection profiling to help optimize page loads

Since the branch point for Aurora is approaching in less than a week, I don’t expect many more probes for Firefox 7.

Telemetry Future

One problem with doing awesome optimizations that as code changes, they frequently get accidentally undone. I plan to add telemetry to keep tabs on every significant optimization that I do in the future, in addition to retroactively adding it to the past ones. I expect other Mozilla developers to do the same.
In addition to keeping tabs on Firefox performance, we can also learn about JavaScript feature adoption, the kind of hardware (and OS) that users run Firefox on, etc to better match users’ needs.