yunfengzhou-hub commented on code in PR #97: URL: https://github.com/apache/flink-ml/pull/97#discussion_r874490030
########## flink-ml-iteration/src/main/java/org/apache/flink/iteration/datacache/nonkeyed/FsSegmentWriter.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.iteration.datacache.nonkeyed; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.api.common.typeutils.TypeSerializer; +import org.apache.flink.core.fs.FSDataOutputStream; +import org.apache.flink.core.fs.FileSystem; +import org.apache.flink.core.fs.Path; +import org.apache.flink.core.memory.DataOutputView; +import org.apache.flink.core.memory.DataOutputViewStreamWrapper; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.ObjectOutputStream; +import java.util.Optional; + +/** A class that writes cache data to file system. */ +@Internal +public class FsSegmentWriter<T> implements SegmentWriter<T> { + private final FileSystem fileSystem; + + // TODO: adjust the file size limit automatically according to the provided file system. + private static final int CACHE_FILE_SIZE_LIMIT = 100 * 1024 * 1024; // 100MB Review Comment: In Spark the size limit of each block (corresponds to the concept "segment" in this PR) seems to be 2GB[1]. Spark does not deliberately limits the size of each block's file, and the 2GB limit seems to be originated from `Integer.MAX_VALUE`. Flink seems not to have this issue so the possible limitations might just be from file systems (e.g., 4GB in FAT32). I'll remove `CACHE_FILE_SIZE_LIMIT`, while treat IOExceptions caused by file systems as reaching the file system's limit. [1] https://issues.apache.org/jira/browse/SPARK-6235 -- 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
