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ASF GitHub Bot commented on FLINK-7781: --------------------------------------- Github user kl0u commented on a diff in the pull request: https://github.com/apache/flink/pull/4901#discussion_r147649624 --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/rest/handler/legacy/metrics/AbstractAggregatingMetricsHandler.java --- @@ -0,0 +1,223 @@ +/* + * 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.flink.runtime.rest.handler.legacy.metrics; + +import org.apache.flink.runtime.jobmaster.JobManagerGateway; +import org.apache.flink.runtime.rest.handler.legacy.AbstractJsonRequestHandler; +import org.apache.flink.runtime.rest.handler.legacy.JsonFactory; +import org.apache.flink.util.FlinkException; +import org.apache.flink.util.Preconditions; + +import com.fasterxml.jackson.core.JsonGenerator; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.io.StringWriter; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashSet; +import java.util.Iterator; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.CompletionException; +import java.util.concurrent.Executor; + +/** + * Abstract request handler for querying metrics. Subclasses may either that returns a list of all available metrics or + * the values for a set of metrics for a specific entity, or aggregate them across several entities. + * --- End diff -- The above javadoc can be improved. The phrase: "Subclasses may either that returns a list of all available metrics or the values for a set of metrics for a specific entity, or aggregate them across several entities." Seems to be the result of sloppy copy paste. > Support simple on-demand metrics aggregation > -------------------------------------------- > > Key: FLINK-7781 > URL: https://issues.apache.org/jira/browse/FLINK-7781 > Project: Flink > Issue Type: Improvement > Components: Metrics, REST > Affects Versions: 1.4.0 > Reporter: Chesnay Schepler > Assignee: Chesnay Schepler > Fix For: 1.4.0 > > > We should support aggregations (min, max, avg, sum) of metrics in the REST > API. This is primarily about aggregating across subtasks, for example the > number of incoming records across all subtasks. > This is useful for simple use-cases where a dedicated metrics backend is > overkill, and will allow us to provide better metrics in the web UI (since we > can expose these aggregated as well). > I propose to add a new query parameter "agg=[min,max,avg,sum]". As a start > this parameter should only be used for task metrics. (This is simply the main > use-case i have in mind) > The aggregation should (naturally) only work for numeric metrics. > We will need a HashSet of metrics that exist for subtasks of a given tasks > that has to be updated in {{MetricStore#add}}. > All task metrics are either stored as > # {{<subtask-index>.<metric>}} or > # {{<subtask-index>.<operator-name>.<metric>}}. > If a user sends a request {{get=mymetric,agg=sum}}, only the metrics of the > first kind are to be considered. Similarly, given a request > {{get=myoperator.mymetric,agg=sum}} only metrics of the second kind are to be > considered. > Ideally, the name of the aggregated metric (i.e. the original name without > subtask index) is also contained in the list of available metrics. -- This message was sent by Atlassian JIRA (v6.4.14#64029)