[Paamicky]

Description of the issue

Since CWA v1.300061.0, the bundled JMX Metric Gatherer JAR switched Tomcat/JVM metric units to UCUM annotation format ({session}, {thread}, {class}, {collection}, {request}, {error}). The agent's knownNonConvertibleUnits set only contains old-format strings, causing non-convertible unit warning logs every collection interval. No data loss occurs (metrics still publish with unit None), but the log noise degrades readability for customers running Tomcat/JVM monitoring.

Issue: https://issues.amazon.com/issues/CWQS-3574

Description of changes

• Added the six UCUM annotation units ({session}, {error}, {thread}, {request}, {class}, {collection}) to the knownNonConvertibleUnits set in internal/cloudwatch/unit.go. This suppresses the spurious warning logs without changing metric publishing behavior.

License

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

Tests

• Added unit test cases for all six new UCUM annotation units in TestKnownNonStandardUnits
• Verified ToStandardUnit returns no error and maps them to None with scale 0

Requirements

1. Run make fmt and make fmt-sh
2. Run make lint

Integration Tests

To run integration tests against this PR, add the ready for testing label.

[github-actions]

Binary Size Report

linux/amd64

Binary	PR	vs main (486f0c6)	vs v1.300072.0
amazon-cloudwatch-agent	194.7 MB	${\color{red}▲}$ +1.4 MB (+0.7%)	${\color{red}▲}$ +1.4 MB (+0.7%)
amazon-cloudwatch-agent-config-wizard	2.0 MB	+0 B	+0 B
config-downloader	2.0 MB	+0 B	+0 B
config-translator	2.0 MB	+0 B	+0 B
start-amazon-cloudwatch-agent	2.5 MB	+0 B	+0 B
workload-discovery	3.0 MB	+0 B	+0 B
Total	206.3 MB	${\color{red}▲}$ +1.4 MB (+0.7%)	${\color{red}▲}$ +1.4 MB (+0.7%)

linux/amd64 amazon-cloudwatch-agent (last 9 main commits + this PR)

 195 ┤                                        
     ┤                                    ███ 
     ┤                                    ███ 
     ┤                                    ███ 
     ┤                                    ███ 
     ┤                                    ███ 
     ┤                                    ███ 
     ┤                                    ███ 
 193 ┤▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ▄▄▄ ███ 
 MB  └────────────────────────────────────────
      2167834                 v1.300072.0 PR

Notable changes:

• +1.4 MB at PR

linux/arm64

Binary	PR	vs main (486f0c6)	vs v1.300072.0
amazon-cloudwatch-agent	178.5 MB	${\color{red}▲}$ +1.4 MB (+0.8%)	${\color{red}▲}$ +1.4 MB (+0.8%)
amazon-cloudwatch-agent-config-wizard	2.0 MB	+0 B	+0 B
config-downloader	2.0 MB	+0 B	+0 B
config-translator	2.0 MB	+0 B	+0 B
start-amazon-cloudwatch-agent	2.4 MB	+0 B	+0 B
workload-discovery	2.9 MB	+0 B	+0 B
Total	189.8 MB	${\color{red}▲}$ +1.4 MB (+0.8%)	${\color{red}▲}$ +1.4 MB (+0.8%)

windows/amd64

Binary	PR	vs main (486f0c6)	vs v1.300072.0
amazon-cloudwatch-agent.exe	196.1 MB	${\color{red}▲}$ +6.1 KB (+0.0%)	${\color{red}▲}$ +6.1 KB (+0.0%)
amazon-cloudwatch-agent-config-wizard.exe	2.1 MB	+0 B	+0 B
config-downloader.exe	2.1 MB	+0 B	+0 B
config-translator.exe	2.1 MB	+0 B	+0 B
start-amazon-cloudwatch-agent.exe	2.3 MB	+0 B	+0 B
workload-discovery.exe	2.9 MB	+0 B	+0 B
Total	207.7 MB	${\color{red}▲}$ +6.1 KB (+0.0%)	${\color{red}▲}$ +6.1 KB (+0.0%)

Investigating size changes

Use go-size-analyzer to compare binaries:

GOEXPERIMENT=jsonv2 go install github.com/Zxilly/go-size-analyzer/cmd/gsa@latest
gsa diff --old <baseline-binary> --new <new-binary>