Prometheus: a handful of new per-exchange and per-queue metrics

[LoisSotoLopez]

Proposed Changes

Solves the issue explained at #11217

• Defines 3 more rabbit_core_metrics tables, where per queue, per exchange and per queue/exchange metrics will be stored without including a channel ID on the key.
• Initializes those tables and configures rabbit_core_metrics to populate them on channel_stats calls, apart from populating those metrics per channel.
• Configures the rabbit_mgmt and prometheus_rabbitmq_core _metrics_collectors to collect those metrics.
• Provides a few tests in the rabbit_prometheus_http_SUITE

Types of Changes

• Bug fix (non-breaking change which fixes issue #NNNN)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• Documentation improvements (corrections, new content, etc)
• Cosmetic change (whitespace, formatting, etc)
• Build system and/or CI

Checklist

• I have read the CONTRIBUTING.md document
• I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• I have added tests that prove my fix is effective or that my feature works
• All tests pass locally with my changes
• If relevant, I have added necessary documentation to https://github.com/rabbitmq/rabbitmq-website
• If relevant, I have added this change to the first version(s) in release-notes that I expect to introduce it

[michaelklishin]

cd deps/rabbitmq_prometheus
gmake tests

on this branch fails for me with

rabbit_prometheus_http_SUITE > per_object_metrics > globally_configure_per_object_metrics_test
    #1. {error,
            {{assertEqual,
                 [{module,rabbit_prometheus_http_SUITE},
                  {line,413},
                  {expression,
                      "re : run ( Body , \"^rabbitmq_queue_get_ack_total{\" , [ { capture , none } , multiline ] )"},
                  {expected,match},
                  {value,nomatch}]},
             [{rabbit_prometheus_http_SUITE,per_object_metrics_test,2,
                  [{file,"rabbit_prometheus_http_SUITE.erl"},{line,413}]},
              {test_server,ts_tc,3,[{file,"test_server.erl"},{line,1793}]},
              {test_server,run_test_case_eval1,6,
                  [{file,"test_server.erl"},{line,1302}]},
              {test_server,run_test_case_eval,9,
                  [{file,"test_server.erl"},{line,1234}]}]}}

rabbit_prometheus_http_SUITE > per_object_endpoint_metrics > endpoint_per_object_metrics
    #1. {error,
            {{assertEqual,
                 [{module,rabbit_prometheus_http_SUITE},
                  {line,413},
                  {expression,
                      "re : run ( Body , \"^rabbitmq_queue_get_ack_total{\" , [ { capture , none } , multiline ] )"},
                  {expected,match},
                  {value,nomatch}]},
             [{rabbit_prometheus_http_SUITE,per_object_metrics_test,2,
                  [{file,"rabbit_prometheus_http_SUITE.erl"},{line,413}]},
              {test_server,ts_tc,3,[{file,"test_server.erl"},{line,1793}]},
              {test_server,run_test_case_eval1,6,
                  [{file,"test_server.erl"},{line,1302}]},
              {test_server,run_test_case_eval,9,
                  [{file,"test_server.erl"},{line,1234}]}]}}

and one more error that can be inspected by opening logs/index.html after the CT test run.

[LoisSotoLopez]

cd deps/rabbitmq_prometheus
gmake tests

on this branch fails for me with

rabbit_prometheus_http_SUITE > per_object_metrics > globally_configure_per_object_metrics_test
    #1. {error,
            {{assertEqual,
                 [{module,rabbit_prometheus_http_SUITE},
                  {line,413},
                  {expression,
                      "re : run ( Body , \"^rabbitmq_queue_get_ack_total{\" , [ { capture , none } , multiline ] )"},
                  {expected,match},
                  {value,nomatch}]},
             [{rabbit_prometheus_http_SUITE,per_object_metrics_test,2,
                  [{file,"rabbit_prometheus_http_SUITE.erl"},{line,413}]},
              {test_server,ts_tc,3,[{file,"test_server.erl"},{line,1793}]},
              {test_server,run_test_case_eval1,6,
                  [{file,"test_server.erl"},{line,1302}]},
              {test_server,run_test_case_eval,9,
                  [{file,"test_server.erl"},{line,1234}]}]}}

rabbit_prometheus_http_SUITE > per_object_endpoint_metrics > endpoint_per_object_metrics
    #1. {error,
            {{assertEqual,
                 [{module,rabbit_prometheus_http_SUITE},
                  {line,413},
                  {expression,
                      "re : run ( Body , \"^rabbitmq_queue_get_ack_total{\" , [ { capture , none } , multiline ] )"},
                  {expected,match},
                  {value,nomatch}]},
             [{rabbit_prometheus_http_SUITE,per_object_metrics_test,2,
                  [{file,"rabbit_prometheus_http_SUITE.erl"},{line,413}]},
              {test_server,ts_tc,3,[{file,"test_server.erl"},{line,1793}]},
              {test_server,run_test_case_eval1,6,
                  [{file,"test_server.erl"},{line,1302}]},
              {test_server,run_test_case_eval,9,
                  [{file,"test_server.erl"},{line,1234}]}]}}

and one more error that can be inspected by opening logs/index.html after the CT test run.

Yep. Should be fixed up right now. Wasn't expecting the core team to look at draft PRs. Won't open them any more if that's the case. 👍

[gomoripeti]

this is the opposite of the intended behaviour. If VHostsFilter is undefined (false) then metrics from all vhosts should be included
After second thought this clauses is not needed as the last clause of get_data which just calls ets:tab2list(Table). will cover what is needed

[michaelklishin]

@LoisSotoLopez @gomoripeti thank you. This will ship in 4.0 this fall.

I'd appreciate if your rabbitmq-server fork was updated a little bit more frequently than once every ≈ 4 weeks. Rebasing a triple digit number of commits can take a while.

[michaelklishin]

I'm afraid deps/rabbitmq_prometheus test suites reliably fail with this PR, even with the new tests excluded from mixed version runs that they cannot possibly pass (against a 3.13.x node) #11687.