Remove experimental label from apollo usage reporting configs

[bonnici]

Removes the experimental label and renames some config options related to Apollo usage reporting:

• experimental_apollo_metrics_generation_mode has been removed since the Rust implementation has been the default since v1.49.0 and it is generating reports identical to the router-bridge implementation
• telemetry.apollo.experimental_apollo_signature_normalization_algorithm is now telemetry.apollo.signature_normalization_algorithm
• telemetry.apollo.experimental_apollo_metrics_reference_mode is now telemetry.apollo.metrics_reference_mode

The defaults have not been changed.

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Complete the checklist (and note appropriate exceptions) before the PR is marked ready-for-review.

• Changes are compatible¹
• Documentation² completed
• Performance impact assessed and acceptable
• Tests added and passing³
  • Unit Tests
  • Integration Tests
  • Manual Tests

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Notes

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1. It may be appropriate to bring upcoming changes to the attention of other (impacted) groups. Please endeavour to do this before seeking PR approval. The mechanism for doing this will vary considerably, so use your judgement as to how and when to do this. ↩

2. Configuration is an important part of many changes. Where applicable please try to document configuration examples. ↩

3. Tick whichever testing boxes are applicable. If you are adding Manual Tests, please document the manual testing (extensively) in the Exceptions. ↩

[router-perf]

CI performance tests

• const - Basic stress test that runs with a constant number of users
• demand-control-instrumented - A copy of the step test, but with demand control monitoring and metrics enabled
• demand-control-uninstrumented - A copy of the step test, but with demand control monitoring enabled
• enhanced-signature - Enhanced signature enabled
• events - Stress test for events with a lot of users and deduplication ENABLED
• events_big_cap_high_rate - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity
• events_big_cap_high_rate_callback - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity using callback mode
• events_callback - Stress test for events with a lot of users and deduplication ENABLED in callback mode
• events_without_dedup - Stress test for events with a lot of users and deduplication DISABLED
• events_without_dedup_callback - Stress test for events with a lot of users and deduplication DISABLED using callback mode
• extended-reference-mode - Extended reference mode enabled
• large-request - Stress test with a 1 MB request payload
• no-tracing - Basic stress test, no tracing
• reload - Reload test over a long period of time at a constant rate of users
• step-jemalloc-tuning - Clone of the basic stress test for jemalloc tuning
• step-local-metrics - Field stats that are generated from the router rather than FTV1
• step-with-prometheus - A copy of the step test with the Prometheus metrics exporter enabled
• step - Basic stress test that steps up the number of users over time
• xlarge-request - Stress test with 10 MB request payload
• xxlarge-request - Stress test with 100 MB request payload

[goto-bus-stop]

Hm, shouldn't these eventually be removed and only the "new" and "enhanced" modes be available?

[bonnici]

Hm, shouldn't these eventually be removed and only the "new" and "enhanced" modes be available?

Yeah the plan is to do this slowly - the defaults will change in router 2.0 and legacy options will be removed in 3.0. I think apollo_metrics_generation_mode:legacy will also be removed in router 2.0.

[goto-bus-stop]

We may want to remove legacy in 1.x for LTS too, I think, since it requires JS.

[goto-bus-stop]

Or coming at it from a different angle--the metrics_generation_mode: legacy uses the old JavaScript implementation. If the Rust implementation works well (as it appears to do), what's the point in continuing to support the legacy mode?

[goto-bus-stop]

Suggested change

	* `experimental_apollo_metrics_generation_mode` is now `apollo_metrics_generation_mode`
	* `experimental_apollo_metrics_generation_mode` is removed

[bonnici]

Oops thanks, this must have been a copy-paste error. I had something else to put here.

[bonnici]

@goto-bus-stop this should be good to go now, can you take a look so that I can get it into the 1.54 release?

[lrlna]

once the title is added to the changeset, it looks good to me! I am glad we are getting rid of one other thing that relies on JS!

Committed suggestion