mimaison commented on code in PR #22779: URL: https://github.com/apache/kafka/pull/22779#discussion_r3545453126
########## server/src/main/java/org/apache/kafka/server/logger/Log4jControllerRegistration.java: ########## @@ -0,0 +1,51 @@ +/* + * 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.server.logger; + +import org.apache.kafka.common.utils.Utils; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.concurrent.atomic.AtomicBoolean; + +/** + * Registers the {@link LoggingController} MBean, which lets users dynamically alter log4j levels + * at runtime. The MBean is registered only once, on the first call to {@link #register()}. + */ +public final class Log4jControllerRegistration { + + private static final Logger LOGGER = LoggerFactory.getLogger(Log4jControllerRegistration.class); + + private static final AtomicBoolean REGISTERED = new AtomicBoolean(false); + + private static final String MBEAN_TYPE = "kafka.Log4jController"; + private static final String MBEAN_NAME = "kafka:type=" + MBEAN_TYPE; + + private Log4jControllerRegistration() { + } + + public static void register() { + if (REGISTERED.compareAndSet(false, true)) { + if (Utils.registerMBean(new LoggingController(), MBEAN_NAME)) { + LOGGER.info("Registered `{}` MBean", MBEAN_NAME); + } else { + LOGGER.warn("Couldn't register `{}` MBean", MBEAN_NAME); Review Comment: I wonder if we actually need this branch. When `registerMBean()` returns `false` it already prints an error message with a similar message. It seems the previous catch clause in the Scala code was unreachable as `registerMBean()` can't throw. -- 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]
