1782283 - `PLACES_DATABASE_PAGESIZE_B` histogram has 99.58% values in one bucket: is it still useful?

Status: RESOLVED FIXED

(Toolkit :: Places, defect, P3)

Description

[Michael Comella (:mcomella) [NI reported issues only: ex-Mozilla]]

The metric PLACES_DATABASE_PAGESIZE_B (probe dictionary) has 99.58% of its values in one bucket of its histogram and 0.41% of samples in another. This makes me wonder: is it still telling us something useful? If not, should we remove it?

The probe started collection in FF Nightly 38 (2015) and FF Beta 50 (2016) so I wonder if it used to measure something more varied but, since then, the data has become more uniform.

Comment 1

[Marco Bonardo [:mak]]

This is a positive sign. Many years ago we changed the database page size from 4k to 32k, based on performance measurement Taras Glek made on Sqlite performance across modern filesystems and disks.
We couldn't immediately change the page size for everyone, cause that requires the database to be vacuumed, that is a slow process, so we do that on maintenance... plus there are various cases where doing such maintenance is not possible.
This was a multi-years process.

Is this probe still useful? Likely not, a small percentage of users staying back is pathologic. and we can't really fix it. Those users will just miss a small perf increase, but the product is functional.

Comment 2

[Abhishek[: unavailable till 11 May]]

I am looking for some bugs, and I tried to understand it but was not able to get it, can You please guide me, what changes it wants

Comment 3

[Saira]

I would like to get more information on this so that I can make my first contribution here. I am an outreachy applicant

Comment 4

[Marco Bonardo [:mak]]

The scope is to remove references to PLACES_DATABASE_PAGESIZE_B and any relevant code supporting them.

Comment 5

[Abhishek[: unavailable till 11 May]]

Attachment: Bug 1782283 - removed references to PLACES_DATABASE_PAGESIZE_B and code supporting them r=mak

Comment 6

[Abhishek[: unavailable till 11 May]]

Sir, after making the changes, I run a complete build to check for errors, and it was successful, please review the patch and guide me if further changes are required or if I made some mistakes. Thanks.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/a5e9a84e1d67
removed references to PLACES_DATABASE_PAGESIZE_B and code supporting them r=mak

Comment 8

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/a5e9a84e1d67