Remove support for expvar-backed metrics

[joeyyy09]

Which problem is this PR solving?

• Part of [deprecation] Remove support for expvar metrics #4722

Description of the changes

• This PR removes deprecated expvar CLI flags for expvar-backed metrics
• The internal parameters/settings of some components are still exposed via expvar. The implementation was changed to no longer depend on go-kit, thus reducing the dependencies

How was this change tested?

• Tested locally by running the application without the deprecated flags to ensure that it functions correctly.

Checklist

• I have read https://github.com/jaegertracing/jaeger/blob/master/CONTRIBUTING_GUIDELINES.md
• I have signed all commits
• I have added unit tests for the new functionality
• [] I have run lint and test steps successfully
  • for jaeger: make lint test
  • for jaeger-ui: yarn lint and yarn test

[yurishkuro]

I would start with deleting internal/metrics/expvar and then making sure make build-binaries-(your platform) is ok.

[joeyyy09]

I would start with deleting internal/metrics/expvar and then making sure make build-binaries-(your platform) is ok.

Yeah, i removed them and made sure the build is okay.

[joeyyy09]

@yurishkuro can you review these changes and let me know if i've got to change any more?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.20%. Comparing base (695f230) to head (6e06128).

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #5437       +/-   ##
===========================================
+ Coverage   54.23%   96.20%   +41.96%     
===========================================
  Files         160      330      +170     
  Lines        8369    16151     +7782     
===========================================
+ Hits         4539    15538    +10999     
+ Misses       3384      437     -2947     
+ Partials      446      176      -270     

Flag	Coverage Δ
badger_v1	8.05% <ø> (ø)
badger_v2	1.93% <ø> (ø)
cassandra-3.x-v1	16.43% <ø> (ø)
cassandra-3.x-v2	1.85% <ø> (ø)
cassandra-4.x-v1	16.43% <ø> (ø)
cassandra-4.x-v2	1.85% <ø> (ø)
elasticsearch-7.x-v1	18.89% <ø> (+0.01%)	⬆️
elasticsearch-8.x-v1	19.08% <ø> (ø)
elasticsearch-8.x-v2	19.08% <ø> (+0.01%)	⬆️
grpc_v1	9.53% <ø> (+0.01%)	⬆️
grpc_v2	7.58% <ø> (ø)
kafka	9.78% <ø> (ø)
opensearch-1.x-v1	18.92% <ø> (-0.02%)	⬇️
opensearch-2.x-v1	18.94% <ø> (+0.01%)	⬆️
opensearch-2.x-v2	18.92% <ø> (ø)
unittests	93.91% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[yurishkuro]

please make sure make lint test are green

[joeyyy09]

please make sure make lint test are green

Yeah, fixed them. Thanks for the help! Is there anything i need to change?

[yurishkuro]

You need to query Prometheus endpoint on each binary before and after changes to make sure no changes to metrics names happen.

[joeyyy09]

You need to query Prometheus endpoint on each binary before and after changes to make sure no changes to metrics names happen.

Yeah, I'll verify this once.

[joeyyy09]

@yurishkuro I've resolved all the edits, thank you for helping me out. Absolutely sorry for messing up the namespaces. Can you please let me know if there's anything more i need to do? I'm willing to make the entire changes till this issue gets resolved.

[yurishkuro]

I still see breaking changes. You need to test that the metrics names are the same, by running each of the main Jaeger components from your branch and from main (e.g. SPAN_STORAGE_TYPE=grpc-plugin go run ./cmd/query) and comparing the output of curl http://localhost:16687/metrics (admin port will be different for different binaries, see logs)

[joeyyy09]

I still see breaking changes. You need to test that the metrics names are the same, by running each of the main Jaeger components from your branch and from main (e.g. SPAN_STORAGE_TYPE=grpc-plugin go run ./cmd/query) and comparing the output of curl http://localhost:16687/metrics (admin port will be different for different binaries, see logs)

Okay, will work on it!