/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.beam.sdk.metrics;
import org.apache.beam.sdk.PipelineResult;
import org.apache.beam.sdk.annotations.Experimental;
import org.apache.beam.sdk.annotations.Experimental.Kind;
/**
* Methods for interacting with the metrics of a pipeline that has been executed. Accessed via
* {@link PipelineResult#metrics()}.
*/
@Experimental(Kind.METRICS)
public abstract class MetricResults {
/**
* Query for all metric values that match a given filter.
*
* <p>The {@code filter} may filter based on the namespace and/or name of the metric, as well as
* the step that reported the metric.
*
* <p>For each type of metric, the result contains an iterable of all metrics of that type that
* matched the filter. Each {@link MetricResult} includes the name of the metric, the step in
* which it was reported and the {@link MetricResult#committed} and
* {@link MetricResult#attempted} values.
*
* <p>Note that runners differ in their support for committed and attempted values.
*
* <p>Example: Querying the metrics reported from the {@code SomeDoFn} example in {@link Metrics}
* could be done as follows:
* <pre>{@code
* Pipeline p = ...;
* p.apply("create1", Create.of("hello")).apply("myStepName1", ParDo.of(new SomeDoFn()));
* p.apply("create2", Create.of("world")).apply("myStepName2", ParDo.of(new SomeDoFn()));
* PipelineResult result = p.run();
* MetricResults metrics = result.metrics();
* MetricQueryResults metricResults = metrics.queryMetrics(new MetricsFilter.Builder()
* .addNameFilter("my-counter")
* .addStepFilter("myStepName1").addStepFilter("myStepName2")
* .build());
* Iterable<MetricResult<Long>> counters = metricResults.counters();
* // counters should contain the value of my-counter reported from each of the ParDo
* // applications.
* }</pre>
*/
public abstract MetricQueryResults queryMetrics(MetricsFilter filter);
}