Github user zentol commented on a diff in the pull request: https://github.com/apache/flink/pull/5857#discussion_r191174704 --- Diff: flink-metrics/flink-metrics-prometheus/src/main/java/org/apache/flink/metrics/prometheus/AbstractPrometheusReporter.java --- @@ -0,0 +1,283 @@ +/* + * 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.metrics.prometheus; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.metrics.CharacterFilter; +import org.apache.flink.metrics.Counter; +import org.apache.flink.metrics.Gauge; +import org.apache.flink.metrics.Histogram; +import org.apache.flink.metrics.Meter; +import org.apache.flink.metrics.Metric; +import org.apache.flink.metrics.MetricConfig; +import org.apache.flink.metrics.MetricGroup; +import org.apache.flink.metrics.reporter.MetricReporter; +import org.apache.flink.runtime.metrics.groups.AbstractMetricGroup; +import org.apache.flink.runtime.metrics.groups.FrontMetricGroup; + +import io.prometheus.client.Collector; +import io.prometheus.client.CollectorRegistry; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.AbstractMap; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collections; +import java.util.HashMap; +import java.util.LinkedList; +import java.util.List; +import java.util.Map; +import java.util.regex.Pattern; + + +/** + * base prometheus reporter for prometheus metrics. + */ +@PublicEvolving +public abstract class AbstractPrometheusReporter implements MetricReporter { + + private static final Logger LOG = LoggerFactory.getLogger(AbstractPrometheusReporter.class); --- End diff -- it is a bit icky to have a separate loggers in the base and sub classes. Define the logger as below instead and update all logger usages. ``` protected final Logger log = LoggerFactory.getLogger(getClass()); ```
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