ZOOKEEPER-256. support use of JMX to manage log4j configuration at runtime. (pat via mahadev)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/zookeeper/trunk@728825 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -88,6 +88,9 @@ form. (pat via mahadev)
    ZOOKEEPER-246. review error code definition in both source and docs. (pat
 via mahadev)
 
+   ZOOKEEPER-256. support use of JMX to manage log4j configuration at runtime.
+(pat via mahadev)
+
 Release 3.0.0 - 2008-10-21
 
 Non-backward compatible changes:

src/java/jmx/org/apache/zookeeper/server/ManagedUtil.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.zookeeper.server;
+
+import java.lang.management.ManagementFactory;
+import java.util.Enumeration;
+
+import javax.management.JMException;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+import org.apache.log4j.jmx.HierarchyDynamicMBean;
+import org.apache.log4j.spi.LoggerRepository;
+
+/**
+ * Shared utilities
+ */
+public class ManagedUtil {
+    /**
+     * Register the log4j JMX mbeans. Set environment variable
+     * "zookeeper.jmx.log4j.disable" to true to disable registration.
+     * @see http://logging.apache.org/log4j/1.2/apidocs/index.html?org/apache/log4j/jmx/package-summary.html
+     * @throws JMException if registration fails
+     */
+    public static void registerLog4jMBeans() throws JMException {
+        if (Boolean.getBoolean("zookeeper.jmx.log4j.disable") == true) {
+            return;
+        }
+        
+        MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
+
+        // Create and Register the top level Log4J MBean
+        HierarchyDynamicMBean hdm = new HierarchyDynamicMBean();
+
+        ObjectName mbo = new ObjectName("log4j:hiearchy=default");
+        mbs.registerMBean(hdm, mbo);
+
+        // Add the root logger to the Hierarchy MBean
+        Logger rootLogger = Logger.getRootLogger();
+        hdm.addLoggerMBean(rootLogger.getName());
+
+        // Get each logger from the Log4J Repository and add it to
+        // the Hierarchy MBean created above.
+        LoggerRepository r = LogManager.getLoggerRepository();
+        Enumeration enumer = r.getCurrentLoggers();
+        Logger logger = null;
+
+        while (enumer.hasMoreElements()) {
+           logger = (Logger) enumer.nextElement();
+           hdm.addLoggerMBean(logger.getName());
+        }
+    }
+
+}

src/java/jmx/org/apache/zookeeper/server/ManagedZooKeeperServerMain.java

@@ -23,11 +23,12 @@ import static org.apache.zookeeper.server.ServerConfig.getClientPort;
 import java.io.File;
 import java.io.IOException;
 
+import javax.management.JMException;
+
 import org.apache.log4j.Logger;
 import org.apache.zookeeper.jmx.server.ConnectionMXBean;
 import org.apache.zookeeper.jmx.server.DataTreeMXBean;
 import org.apache.zookeeper.jmx.server.ZooKeeperServerMXBean;
-import org.apache.zookeeper.server.persistence.FileTxnLog;
 import org.apache.zookeeper.server.persistence.FileTxnSnapLog;
 import org.apache.zookeeper.server.util.ZooKeeperObserverManager;
 
@@ -62,6 +63,12 @@ public class ManagedZooKeeperServerMain extends ZooKeeperServerMain {
      * @param args command line parameters.
      */
     public static void main(String[] args) {
+        try {
+            ManagedUtil.registerLog4jMBeans();
+        } catch (JMException e) {
+            LOG.warn("Unable to register log4j JMX control", e);
+        }
+
         try {
             ServerConfig.parse(args);
         } catch(Exception e) {

src/java/jmx/org/apache/zookeeper/server/quorum/ManagedQuorumPeerMain.java

@@ -23,6 +23,8 @@ import static org.apache.zookeeper.server.ServerConfig.getClientPort;
 import java.io.File;
 import java.io.IOException;
 
+import javax.management.JMException;
+
 import org.apache.log4j.Logger;
 import org.apache.zookeeper.jmx.server.ConnectionMXBean;
 import org.apache.zookeeper.jmx.server.DataTreeMXBean;
@@ -31,18 +33,12 @@ import org.apache.zookeeper.jmx.server.quorum.LeaderElectionMXBean;
 import org.apache.zookeeper.jmx.server.quorum.LocalPeerMXBean;
 import org.apache.zookeeper.jmx.server.quorum.QuorumMXBean;
 import org.apache.zookeeper.jmx.server.quorum.RemotePeerMXBean;
+import org.apache.zookeeper.server.ManagedUtil;
 import org.apache.zookeeper.server.ManagedZooKeeperServerMain;
 import org.apache.zookeeper.server.NIOServerCnxn;
 import org.apache.zookeeper.server.ObservableNIOServerCnxn;
 import org.apache.zookeeper.server.ServerConfig;
-import org.apache.zookeeper.server.ZooKeeperServer;
-import org.apache.zookeeper.server.ZooTrace;
-import org.apache.zookeeper.server.persistence.FileTxnLog;
 import org.apache.zookeeper.server.persistence.FileTxnSnapLog;
-import org.apache.zookeeper.server.util.ConnectionObserver;
-import org.apache.zookeeper.server.util.ObserverManager;
-import org.apache.zookeeper.server.util.QuorumPeerObserver;
-import org.apache.zookeeper.server.util.ServerObserver;
 import org.apache.zookeeper.server.util.ZooKeeperObserverManager;
 
 /**
@@ -92,6 +88,12 @@ public class ManagedQuorumPeerMain {
             System.exit(2);
         }
         if (!QuorumPeerConfig.isStandalone()) {
+            try {
+                ManagedUtil.registerLog4jMBeans();
+            } catch (JMException e) {
+                LOG.warn("Unable to register log4j JMX control", e);
+            }
+
             ZooKeeperObserverManager.setAsConcrete();
             runPeer(new QuorumPeer.Factory() {
                 public QuorumPeer create(NIOServerCnxn.Factory cnxnFactory)