divijvaidya commented on code in PR #14628: URL: https://github.com/apache/kafka/pull/14628#discussion_r1371459493
########## metadata/src/main/java/org/apache/kafka/metadata/properties/PropertiesUtils.java: ########## @@ -0,0 +1,102 @@ +/* + * 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.kafka.metadata.properties; + +import org.apache.kafka.common.utils.Utils; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStreamWriter; +import java.io.PrintWriter; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Paths; +import java.util.Properties; + +public final class PropertiesUtils { + /** + * Writes a Java Properties object to a file. + * + * @param props The Properties object. + * @param path The file to write to. + * @throws IOException + */ + public static void writePropertiesFile( + Properties props, + String path + ) throws IOException { + File tempFile = new File(path + ".tmp"); + try ( + FileOutputStream fos = new FileOutputStream(tempFile, false); + OutputStreamWriter osw = new OutputStreamWriter(fos, StandardCharsets.UTF_8); + PrintWriter pw = new PrintWriter(osw) + ) { + props.store(pw, ""); + fos.flush(); + fos.getFD().sync(); Review Comment: for my better understanding, could you please explain why fsync() is necessary for the temp file? I am curious because it is going to be renamed in the next step and if there is a process crash losing data in page cache, we anyways won't want to re-use this temp file. ########## metadata/src/main/java/org/apache/kafka/metadata/properties/PropertiesUtils.java: ########## @@ -0,0 +1,102 @@ +/* + * 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.kafka.metadata.properties; + +import org.apache.kafka.common.utils.Utils; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStreamWriter; +import java.io.PrintWriter; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Paths; +import java.util.Properties; + +public final class PropertiesUtils { Review Comment: Can we extract this as a "type" of file (perhaps called PropertiesFile) that Kafka creates similar to how we have a type `CheckpointFile` or `Snapshots`? This new type of file could be re-used in future for other use case. It would also help unify places where we are writing to file system and prevent accidental fsync() which we are trying to solve in https://github.com/apache/kafka/pull/14242 ########## metadata/src/main/java/org/apache/kafka/metadata/properties/PropertiesUtils.java: ########## @@ -0,0 +1,102 @@ +/* + * 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.kafka.metadata.properties; + +import org.apache.kafka.common.utils.Utils; + +import java.io.File; +import java.io.FileOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStreamWriter; +import java.io.PrintWriter; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Paths; +import java.util.Properties; + +public final class PropertiesUtils { + /** + * Writes a Java Properties object to a file. + * + * @param props The Properties object. + * @param path The file to write to. + * @throws IOException + */ + public static void writePropertiesFile( + Properties props, + String path + ) throws IOException { + File tempFile = new File(path + ".tmp"); + try ( + FileOutputStream fos = new FileOutputStream(tempFile, false); + OutputStreamWriter osw = new OutputStreamWriter(fos, StandardCharsets.UTF_8); + PrintWriter pw = new PrintWriter(osw) + ) { + props.store(pw, ""); + fos.flush(); + fos.getFD().sync(); + } + File targetFile = new File(path); + try { + Utils.atomicMoveWithFallback(tempFile.toPath(), targetFile.toPath()); Review Comment: same as above, do we want to use `atomicMoveWithFallback` with `needFlushParentDir` = false here? ########## metadata/src/main/java/org/apache/kafka/metadata/properties/MetaProperties.java: ########## @@ -0,0 +1,266 @@ +/* + * 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.kafka.metadata.properties; + +import org.apache.kafka.common.Uuid; + +import java.util.Objects; +import java.util.Optional; +import java.util.OptionalInt; +import java.util.Properties; + +/** + * An immutable class which contains the per-log-directory information stored in an individual + * meta.properties file. + */ +public final class MetaProperties { Review Comment: Do we want to move this in core module? Asking because (correct me if I am wrong), these properties are not coupled with Kafka control plane / metadata handling layer. -- 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: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
