afedulov commented on a change in pull request #15054: URL: https://github.com/apache/flink/pull/15054#discussion_r602433607
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/webmonitor/stats/OperatorStatsTracker.java ########## @@ -0,0 +1,56 @@ +/* + * 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.webmonitor.stats; + +import org.apache.flink.runtime.executiongraph.AccessExecutionJobVertex; +import org.apache.flink.util.FlinkException; + +import java.util.Optional; + +/** + * Interface for a tracker of statistics for {@link AccessExecutionJobVertex}. + * + * @param <T> Type of statistics to track + */ +public interface OperatorStatsTracker<T extends Stats> { + + /** + * Returns statistics for an operator. Automatically triggers sampling request if statistics are + * not available or outdated. + * + * @param vertex Operator to get the stats for. + * @return Statistics for an operator + */ + Optional<T> getOperatorStats(AccessExecutionJobVertex vertex); + + /** + * Cleans up the operator stats cache if it contains timed out entries. + * + * <p>The Guava cache only evicts as maintenance during normal operations. If this handler is + * inactive, it will never be cleaned. Review comment: Good catch, it bubbled up during the interface extraction. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
