= Spring Boot sample with Redis export for metrics.
Start redis, e.g. with [Docker Compose]()
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$ docker-compose up
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Run the app and ping the home page (http://localhost:8080) a few times. Go and look at
the result in Redis, e.g.
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----
$ redis-cli
127.0.0.1:6379> keys *
1) "keys.spring.metrics"
2) "spring.metrics.counter.status.200.root"
3) "spring.metrics.gauge.response.root"
127.0.0.1:6379> zrange keys.spring.metrics 0 0 WITHSCORES
1) "spring.metrics.counter.status.200.root"
2) "4"
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There is also an `AggregateMetricReader` with public metrics in the application context,
and you can see the result in the "/metrics" (metrics with names in "aggregate.*").
The way the Redis repository was set up (with a random key in the metric names) makes the
aggregates work across restarts of the same application, or across a scaled up application
running in multiple processes. E.g.
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----
$ curl localhost:8080/metrics
{
...
"aggregate.application.counter.status.200.metrics": 12,
"aggregate.application.counter.status.200.root": 29,
"aggregate.application.gauge.response.metrics": 43,
"aggregate.application.gauge.response.root": 5,
"counter.status.200.root": 2,
"counter.status.200.metrics": 1,
"gauge.response.metrics": 43,
"gauge.response.root": 5
}
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