1690438 - Add zero_byte_length Telemetry for DTD loads

Status: RESOLVED FIXED

(Core :: XML, task)

Description

[Zibi Braniecki [:zbraniecki][:gandalf]]

As part of the crusade against Yellow Screen of Death, we would like to get telemetry probe for events of zero_byte_length loads of DTD files to validate the hypothesis that zero_byte_length loads of DTD are responsible for many cases of YSOD.

The probe should be located either in nsExpatDriver::HandleExternalEntityRef or OpenInputStreamFromExternalDTD and have the following event signature:

type: event
category: zero_byte_load
descriptuon: >-
  Collection of zero_byte_load events as part of the Yellow Screen of Death analysis.
  Theoretically, there should be no zero-byte-length loads, so every load of that type
  indicates an error, likely breaking user experience.
method: load
objects:
  - "ftl"
  - "dtd"
  - "properties"
  - "js"
  - "xml"
  - "xhtml"
products: ["firefox"]
release_channel_collection: opt-out
value: URL
extra_key:
 - sync: bool

Each object will have its own bug. This one is for DTD event.

Comment 1

[Kershaw Chang [:kershaw]]

Attachment: Bug 1690438 - Add telemetry for zero byte loads in nsJARChannel::Open

Comment 2

[Kershaw Chang [:kershaw]]

Attachment: bug1690438_telemetry_data_review.txt

Comment 3

[Zibi Braniecki [:zbraniecki][:gandalf]]

I want to also point out that in bug 1690445 we plan to remove the previous jar channel telemetry that didn't yield any interesting results.

I'll wait with the removal until we start seeing any results from this probe to give us a chance to correlate results in case there are any.

Comment 4

[Chris H-C :chutten]

Comment on attachment 9202139 [details]
bug1690438_telemetry_data_review.txt

DATA COLLECTION REVIEW RESPONSE:

Is there or will there be documentation that describes the schema for the ultimate data set available publicly, complete and accurate?

Yes.

Is there a control mechanism that allows the user to turn the data collection on and off?

Yes. This collection is Telemetry so can be controlled through Firefox's Preferences.

If the request is for permanent data collection, is there someone who will monitor the data over time?

Yes, :zbraniecki is responsible.

Using the category system of data types on the Mozilla wiki, what collection type of data do the requested measurements fall under?

Category 1, Technical.

Is the data collection request for default-on or default-off?

Default on for all channels.

Does the instrumentation include the addition of any new identifiers?

No.

Is the data collection covered by the existing Firefox privacy notice?

Yes.

Does there need to be a check-in in the future to determine whether to renew the data?

No. This collection is permanent.

---

Result: datareview+

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8ef970eae3d1
Add telemetry for zero byte loads in nsJARChannel::Open r=zbraniecki

Comment 6

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/8ef970eae3d1