paul-rogers commented on a change in pull request #2000: DRILL-7607: support dynamic credit based flow control URL: https://github.com/apache/drill/pull/2000#discussion_r385996692
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/rpc/DynamicSemaphore.java ########## @@ -0,0 +1,72 @@ +/* + * 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.drill.exec.rpc; + +import java.util.concurrent.Semaphore; +import java.util.concurrent.atomic.AtomicBoolean; +import java.util.concurrent.locks.ReentrantLock; + Review comment: This class would benefit from a description, perhaps a form of that in your commit message. One bit of info missing is the goal of the credit. I gather it is to speed up the query by allowing the upstream to get further ahead by using receiver-side memory to buffer results. That is, it is a performance/memory tradeoff. Looks like the credit itself is computed elsewhere, so I'm hoping for a description of the algorithm there. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
