[intent to deprecate] private symbol infrastructure for crash report ingestion

[William Kahn-Greene]

(cross-posted: stability, crash-reporting-wg, dev-platform)

Summary:

On July 10th, 2023, I intend to deprecate and remove support for private symbols in crash ingestion.

Research bug: bug 1838892

If you have concerns, please add a comment to the bug or email me (wil...@mozilla.com).

Longer explanation:

As part of the build process for Mozilla products, debug symbols are extracted and uploaded to the Mozilla Symbols Server. These symbols are public--they are available to anyone in the world including the crash ingestion pipeline which uses them for processing crash reports.

In 2015, we created a way for Adobe to upload symbols for Flash which were stored in a different place that was not public and could _only_ be used by the crash ingestion processor. We call this the private symbols bucket. Only a handful of Adobe and Intel accounts can upload symbols into this bucket and only the crash ingestion processor can access the symbols and use them.

In bug #1838892, I audited the situation. No one has uploaded symbols since the end of 2020 when the last version of Flash shipped. The crash ingestion processor hasn't used symbols from the private symbols bucket to process crash reports in at least the last 6 months. The private symbols bucket only contains Flash symbols--nothing else.

The infrastructure supporting the private symbols bucket is incredibly wonky. Removing it simplifies the ongoing GCP migration for both Tecken (the Mozilla Symbols Server) and Socorro (the crash ingestion pipeline). In the future, if we have a need for a private symbols bucket, we can reimplement it in a way that's easier to maintain.