This version is still in development and is not considered stable yet. For the latest stable version, please use Micrometer 1.13.3! |
Meter Provider
It’s a common use-case to attach tags dynamically to a Meter
. Let’s say we execute a job and we want to use a Timer
to instrument it:
Timer.Sample sample = Timer.start(registry);
Result result = job.execute();
Timer timer = Timer.builder("job.execution")
.tag("job.name", "job")
.tag("status", result.status())
.register(registry);
sample.stop(timer);
This lets us dynamically determine the status
tag from the end state of the operation we are timing. There are two drawbacks of doing this:
-
Every time the above is executed, a new
Timer.Builder
instance is created. This increases the amount of data that the GC needs to collect. -
The code above is somewhat boilerplate, it does not let you define the common properties of a Timer and attach what is dynamically changing but everything is always present.
In some cases you can use registry.timer("job.execution", "job.name", "my-job", "status", result.status()) instead of using Timer.Builder which can save you some extra objects but this is not always possible.
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You can resolve both of these issues by using a MeterProvider
. It’s a convenience interface to create new meters from tags using a common "template".
Not every Meter can do this, MeterProvider can be used with Counter , Timer , LongTaskTimer , and DistributionSummary .
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Here’s what you can do instead of the above:
private MeterProvider<Timer> timerProvider = Timer.builder("job.execution")
.tag("job.name", "my-job")
.withRegistry(registry); (1)
// ...
Timer.Sample sample = Timer.start(registry);
Result result = job.execute();
sample.stop(timerProvider.withTags("status", result.status())); (2)
1 | Definition of the MeterProvider for Timer with all the "static" fields necessary. Please note the withRegistry method call. |
2 | Definition of the dynamic tags. Note that only those tags are defined here that are dynamic and everying else is defined where the MeterProvider is created. The withTags method returns a Timer that is created using the tags defined in withTags plus everything else that is defined by the MeterProvider . |
This and the previous example produce the same output, the only difference is the amount of boilerplate in your code and the amount of builder objects created in the heap.