TanYuxin-tyx commented on code in PR #22352: URL: https://github.com/apache/flink/pull/22352#discussion_r1193822060
########## flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/hybrid/tiered/storage/TieredStorageMemoryManager.java: ########## @@ -0,0 +1,96 @@ +/* + * 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.io.network.partition.hybrid.tiered.storage; + +import org.apache.flink.runtime.io.network.buffer.BufferBuilder; +import org.apache.flink.runtime.io.network.buffer.BufferPool; +import org.apache.flink.runtime.io.network.buffer.LocalBufferPool; + +import java.util.List; + +/** + * The {@link TieredStorageMemoryManager} is to request or recycle buffers from {@link + * LocalBufferPool} for different memory owners, for example, the tiers, the buffer accumulator, + * etc. Note that the logic for requesting and recycling buffers is consistent for these owners. + * + * <p>The memory managed by {@link TieredStorageMemoryManager} is categorized into two types: + * long-term occupied memory which cannot be immediately released and short-term occupied memory + * which can be reclaimed quickly and safely. Long-term occupied memory usage necessitates waiting + * for other operations to complete before releasing it, such as downstream consumption. On the + * other hand, short-term occupied memory can be freed up at any time, enabling rapid memory + * recycling for tasks such as flushing memory to disk or remote storage. + * + * <p>This {@link TieredStorageMemoryManager} aim to streamline and harmonize memory management + * across various layers. Instead of tracking the number of buffers utilized by individual users, it + * dynamically calculates a user's maximum guaranteed amount based on the current status of the + * manager and the local buffer pool. Specifically, if a user is a long-term occupied memory user, + * the {@link TieredStorageMemoryManager} does not limit the user's memory usage, while if a user is + * a short-term occupied memory user, the current guaranteed buffers of the user is the left buffers + * in the buffer pool - guaranteed amount of other users (excluding the current user). + */ +public interface TieredStorageMemoryManager { + + /** + * Setup the {@link TieredStorageMemoryManager}. When setting up the manager, the {@link + * TieredStorageMemorySpec}s for different tiered storages should be ready to indicate each + * tiered storage's memory requirement specs. + * + * @param bufferPool the local buffer pool + * @param storageMemorySpecs the memory specs for different tiered storages + */ + void setup(BufferPool bufferPool, List<TieredStorageMemorySpec> storageMemorySpecs); + + /** + * Register a buffer flush call back to flush and recycle all the memory in the user when + * needed. + * + * <p>When the left buffers in the {@link BufferPool} are not enough, {@link + * TieredStorageMemoryManager} will flush the buffers of the user with the registered callback. + * + * @param userBufferFlushCallback the buffer flush call back of the memory user + */ + void registerBufferFlushCallback(Runnable userBufferFlushCallback); + + /** + * Request a {@link BufferBuilder} instance from {@link LocalBufferPool} for a specific owner. + * + * @return the requested buffer + */ + BufferBuilder requestBufferBlocking(); + + /** + * Return the available buffers for the owner. + * + * <p>Note that the available buffers are calculated dynamically based on some conditions, for + * example, the state of the {@link BufferPool}, the {@link TieredStorageMemorySpec} of the + * owner, etc. Review Comment: Fixed and rewrite the docs. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
