steveloughran commented on a change in pull request #2971: URL: https://github.com/apache/hadoop/pull/2971#discussion_r826926887
########## File path: hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/RateLimiting.java ########## @@ -0,0 +1,52 @@ +/* + * 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.hadoop.util; + +import java.time.Duration; + +import org.apache.hadoop.classification.InterfaceAudience; +import org.apache.hadoop.classification.InterfaceStability; + +/** + * Minimal subset of google rate limiter class. + * Can be used to throttle use of object stores where excess load + * will trigger cluster-wide throttling, backoff etc. and so collapse + * performance. + * The time waited is returned as a Duration type. + * The google rate limiter implements this by allowing a caller to ask for + * more capacity than is available. This will be granted + * but the subsequent request will be blocked if the bucket of + * capacity hasn't let refilled to the point where there is + * capacity again. + */ [email protected] [email protected] +public interface RateLimiting { + + /** + * Acquire rate limiter capacity. + * If there is not enough space, the permits will be acquired, + * but the subsequent call will block until the capacity has been + * refilled. + * @param capacity capacity to acquire. + * @return time spent waiting for output. + */ + Duration acquire(int capacity); Review comment: Time does it for us. we are acquiring IO capacity for that second. the next second, the same capacity is available. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
