Interface Meter

Sets up a function that will be called whenever a metric collection is initiated.

If the function is already in the list of callbacks for this Observable, the function is not added a second time.

Only the associated observables can be observed in the callback. Measurements of observables that are not associated observed in the callback are dropped.

Creates a new Counter metric. Generally, this kind of metric when the value is a quantity, the sum is of primary interest, and the event count and value distribution are not of primary interest.

Creates and returns a new Gauge.

Creates and returns a new Histogram.

Creates a new ObservableCounter metric.

The callback SHOULD be safe to be invoked concurrently.

Creates a new ObservableGauge metric.

The callback SHOULD be safe to be invoked concurrently.

Creates a new ObservableUpDownCounter metric.

The callback SHOULD be safe to be invoked concurrently.

Creates a new UpDownCounter metric. UpDownCounter is a synchronous instrument and very similar to Counter except that Add(increment) supports negative increments. It is generally useful for capturing changes in an amount of resources used, or any quantity that rises and falls during a request. Example uses for UpDownCounter:

1. count the number of active requests.
2. count memory in use by instrumenting new and delete.
3. count queue size by instrumenting enqueue and dequeue.
4. count semaphore up and down operations.

Removes a callback previously registered with Meter.addBatchObservableCallback.

The callback to be removed is identified using a combination of the callback itself, and the set of the observables associated with it.