Claude
03bdf7ee87
Companion module for the rewritten ankurm.com Prometheus/Grafana monitoring post. Verified against a real running grafana/otel-lgtm container (not mocked): 8 real requests produce a real orders_placed_total metric queried back from the bundled Prometheus-compatible API with zero management.otlp.* properties, auto-wired entirely by Boot's Docker Compose service-connection detection. Two real findings surfaced along the way and documented rather than smoothed over: @Observed silently produces no span without an explicit ObservedAspect bean (AspectJ weaving alone is not sufficient, despite Micrometer Tracing being active), and OTEL_EXPORTER_OTLP_ENDPOINT already worked on Boot 4.0 via Micrometer's own OtlpConfig fallback -- what's actually new in 4.1 is the rest of the standard OTEL_* surface (verified with OTEL_METRIC_EXPORT_INTERVAL against identical source compiled on both Boot 4.0.8 and 4.1.1). Also fixes the root README's module table, which was missing a row for resilience4j-circuit-breaker (added in a previous commit but never indexed here).
24 lines
1.1 KiB
Plaintext
24 lines
1.1 KiB
Plaintext
Default management.tracing.sampling.probability (0.10, unset in application.yml):
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$ for i in $(seq 101 115); do curl -s -X POST "http://localhost:8080/orders/$i" > /dev/null; done
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# 15 requests sent
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$ curl -s "http://localhost:9090/api/v1/query?query=orders_placed_total"
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# metric value: 15 -- all 15 counted, metrics are never subject to trace sampling
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$ curl -s "http://localhost:3200/api/search?limit=50"
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# trace count increased by 1 -- only ~1 of the 15 requests was sampled into a trace
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Same 15 requests, same app, same collector. Every one produced a metric data point. Roughly
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1 in 10 produced a trace, because trace sampling and metric recording are governed by two
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completely different knobs, and only one of them defaults to "record everything."
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--- with the fulltrace profile (management.tracing.sampling.probability=1.0) ---
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$ mvn -Dspring-boot.run.profiles=fulltrace spring-boot:run
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$ for i in $(seq 401 410); do curl -s -X POST "http://localhost:8080/orders/$i" > /dev/null; done
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# 10 requests sent
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$ curl -s "http://localhost:3200/api/search?limit=50"
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# post /orders traces increased by 10 -- 10 of 10, all of them present
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