With OpenTelemetry trying to become the de-facto standard for Observability of applications/services, where does Micrometer fit in? Micrometer website claims that it is SLF4J for metrics, but does it not contradict OpenTelemetry's Metrics APIs? I wonder if OpenTelemetry's Metric APIs should represent SLF4J and Micrometer should represent an implementation like Log4J.
Appreciate if someone can help me clarify this.
OpenTelemetry is focused on tracing (see zipkin and Jaeger) more than metrics. There is an overlap with Micrometer metrics, but the approach is quite different.
Micrometer is still similar to slf4j since it is the metrics facade for coding to recording metrics. The actual implementation (as you think about log4j) for metrics is Prometheus, Statsd, Datadog, etc.
So OpenTelemetry and Micrometer could both be considered metric abstractions, but since there are different types of metrics (tracing and performance aggregations), they track different things.
Another way to think about this is OpenTelemtry would be useful to measure across many microservices as they hand off requests and you need to trace behavior, while Micrometer would be more useful for tracking a single application's performance and health.
