jembeanhelper.java

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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 2002-2005
*      Sleepycat Software.  All rights reserved.
*
* $Id: JEMBeanHelper.java 4644 2006-09-20 22:40:21Z paul_jack $
*/

package org.archive.util;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import javax.management.Attribute;
import javax.management.AttributeNotFoundException;
import javax.management.InvalidAttributeValueException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanParameterInfo;

import com.sleepycat.je.CheckpointConfig;
import com.sleepycat.je.Database;
import com.sleepycat.je.DatabaseConfig;
import com.sleepycat.je.DatabaseException;
import com.sleepycat.je.DatabaseStats;
import com.sleepycat.je.DbInternal;
import com.sleepycat.je.Environment;
import com.sleepycat.je.EnvironmentConfig;
import com.sleepycat.je.EnvironmentMutableConfig;
import com.sleepycat.je.StatsConfig;

/**
 * JEMBeanHelper is a utility class for the MBean implementation which wants to
 * add management of a JE environment to its capabilities. MBean
 * implementations can contain a JEMBeanHelper instance to get MBean metadata
 * for JE and to set attributes, get attributes, and invoke operations.
 * <p>
 * com.sleepycat.je.jmx.JEMonitor and
 * the example program jmx.JEApplicationMBean are two MBean implementations
 * which provide support different application use cases. See those classes for
 * examples of how to use JEMBeanHelper.
 * <p>This class was copied from the bdb je 2.0 jmx examples.
 */

public class JEMBeanHelper {

    /*
     * A note to JE developers: all available JE attributes and operations are
     * described in the following static info arrays. New management
     * functionality can be added to the helper by adding to the appropriate
     * set of static definitions. For example, if we want to add a new JE
     * attribute called "foo", which is available for open environments, we
     * need to define a new MBeanAttributeInfo in the OPEN_ATTR array. The
     * helper then needs to provide an implementation in set/getAttribute.
     */
    
    /* --------------------- Attributes -------------------------- */

    /* Attribute names. */
    public static final String ATT_ENV_HOME = "environmentHome";
    public static final String ATT_OPEN = "isOpen";
    public static final String ATT_IS_READ_ONLY = "isReadOnly";
    public static final String ATT_IS_TRANSACTIONAL = "isTransactional";
    public static final String ATT_CACHE_SIZE = "cacheSize";
    public static final String ATT_CACHE_PERCENT = "cachePercent";
    public static final String ATT_LOCK_TIMEOUT = "lockTimeout";
    public static final String ATT_IS_SERIALIZABLE = "isSerializableIsolation";
    public static final String ATT_TXN_TIMEOUT = "transactionTimeout";
    public static final String ATT_SET_READ_ONLY = "openReadOnly";
    public static final String ATT_SET_TRANSACTIONAL = "openTransactional";
    public static final String ATT_SET_SERIALIZABLE =
        "openSerializableIsolation";
    
    /* COMMON_ATTR attributes are available for any environment. */
    private static final MBeanAttributeInfo [] COMMON_ATTR = {
        
        new MBeanAttributeInfo(ATT_ENV_HOME,
                               "java.lang.String",
                               "Environment home directory.",
                               true,   // readable
                               false,  // writable
                               false), // isIs
        new MBeanAttributeInfo(ATT_OPEN,
                               "java.lang.Boolean",
                               "True if this environment is open.",
                               true,   // readable
                               false,  // writable
                               true)   // isIs
    };

    /* OPEN_ATTR attributes are available for all open environments. */
    private static final MBeanAttributeInfo [] OPEN_ATTR = {

        new MBeanAttributeInfo(ATT_IS_READ_ONLY,
                               "java.lang.Boolean",
                               "True if this environment is read only.",
                               true,   // readable
                               false,  // writable
                               true),  // isIs
        new MBeanAttributeInfo(ATT_IS_TRANSACTIONAL,
                               "java.lang.Boolean",
                             "True if this environment supports transactions.",
                               true,   // readable
                               false,  // writable
                               true),  // isIs
        new MBeanAttributeInfo(ATT_CACHE_SIZE,
                               "java.lang.Long",
                               "Cache size, in bytes.",
                               true,   // readable
                               true,   // writable
                               false), // isIs
        new MBeanAttributeInfo(ATT_CACHE_PERCENT,
                               "java.lang.Integer",
                               "By default, cache size is (cachePercent * " +
                               "JVM maximum memory. To change the cache size "+
                               "using a percentage of the heap size, set " +
                               "the cache size to 0 and cachePercent to the "+
                               "desired percentage value.",
                               true,   // readable
                               true,   // writable
                               false), // isIs
        new MBeanAttributeInfo(ATT_LOCK_TIMEOUT,
                               "java.lang.Long",
                               "Lock timeout, in microseconds.",
                               true,   // readable
                               false,  // writable
                               false), // isIs
    };

    /* 
     * TRANSACTIONAL_ATTR attributes are available only for open, transactional
     * environments.
     */
    private static final MBeanAttributeInfo [] TRANSACTIONAL_ATTR = {

        new MBeanAttributeInfo(ATT_IS_SERIALIZABLE,
                               "java.lang.Boolean",
                               "True if this environment provides " +
                               "Serializable (degree 3) isolation. The " +
                               "default is RepeatableRead isolation.",
                               true,   // readable
                               false,  // writable
                               true),  // isIs
        new MBeanAttributeInfo(ATT_TXN_TIMEOUT,
                               "java.lang.Long",
                               "Transaction timeout, in seconds. A value " +
                               "of 0 means there is no timeout.",
                               true,   // readable
                               false,  // writable
                               false)  // isIs
    };

    /* 
     * CREATE_ATTR attributes are available when the mbean is configured to
     * support configuration and opening by the mbean. They express the
     * configuration settings.
     */
    private static final MBeanAttributeInfo [] CREATE_ATTR = {
        
        new MBeanAttributeInfo(ATT_SET_READ_ONLY,
                               "java.lang.Boolean",
                               "True if this environment should be opened " +
                               "in readonly mode.",
                               true,   // readable
                               true,   // writable
                               false), // isIs
        new MBeanAttributeInfo(ATT_SET_TRANSACTIONAL,
                               "java.lang.Boolean",
                               "True if this environment should be opened " +
                               "in transactional mode.",
                               true,   // readable
                               true,   // writable
                               false), // isIs
        new MBeanAttributeInfo(ATT_SET_SERIALIZABLE,
                               "java.lang.Boolean",
                               "True if this environment should be opened " +
                               "with serializableIsolation. The default is "+
                               "false.",
                               true,   // readable
                               true,   // writable
                               false), // isIs
    };

    /* --------------------- Operations  -------------------------- */

    /* Operation names */
    static final String OP_CLEAN = "cleanLog";
    static final String OP_EVICT = "evictMemory";
    static final String OP_CHECKPOINT = "checkpoint";
    static final String OP_SYNC = "sync";
    static final String OP_ENV_STAT = "getEnvironmentStats";
    static final String OP_ENV_STAT_STR = "getEnvironmentStatsToString";
    static final String OP_LOCK_STAT = "getLockStats";
    static final String OP_LOCK_STAT_STR = "getLockStatsToString";
    static final String OP_TXN_STAT = "getTxnStats";
    static final String OP_DB_NAMES = "getDatabaseNames";
    static final String OP_DB_STAT = "getDatabaseStats";

    private static final MBeanOperationInfo OP_CLEAN_INFO = 
        new MBeanOperationInfo(OP_CLEAN,
                               "Remove obsolete environment log files. " +
                               "Zero or more log files will be cleaned as " +
                               "necessary to bring the disk space " +
                               "utilization of the environment above the " +
                               "configured minimum utilization threshold " +
                               "as determined by the setting " +
                               "je.cleaner.minUtilization. Returns the " +
                               "number of files cleaned, that will be " +
                               "deleted at the next qualifying checkpoint.",
                               new MBeanParameterInfo[0], // no params
                               "java.lang.Integer",
                               MBeanOperationInfo.UNKNOWN);

    private static final MBeanOperationInfo OP_EVICT_INFO = 
        new MBeanOperationInfo(OP_EVICT,
                               "Reduce cache usage to the threshold " +
                               "determined by the setting " +
                               "je.evictor.useMemoryFloor. ",
                               new MBeanParameterInfo[0], // no params
                               "void",
                               MBeanOperationInfo.UNKNOWN);

    /* parameter for checkpoint operation. */
    private static final MBeanParameterInfo [] checkpointParams = {
        new MBeanParameterInfo ("force", "java.lang.Boolean",
                                "If true, force a checkpoint even if " +
                                "there has been no activity since the last " +
                                "checkpoint. Returns true if a checkpoint " +
                                "executed.")
    };

    private static final MBeanOperationInfo OP_CHECKPOINT_INFO = 
        new MBeanOperationInfo(OP_CHECKPOINT,
                               "Checkpoint the environment.",
                               checkpointParams,
                               "void",
                               MBeanOperationInfo.UNKNOWN);

    private static final MBeanOperationInfo OP_SYNC_INFO = 
        new MBeanOperationInfo(OP_SYNC,
                               "Flush the environment to stable storage.",
                               new MBeanParameterInfo[0], // no params
                               "void",
                               MBeanOperationInfo.UNKNOWN);

    private static final MBeanParameterInfo [] statParams = {
        new MBeanParameterInfo ("clear", "java.lang.Boolean",
                                "If true, reset statistics after reading."),
        new MBeanParameterInfo ("fast", "java.lang.Boolean",
                                "If true, only return statistics which do " +
                                "not require expensive computation.")

    };

    private static final MBeanOperationInfo OP_ENV_STAT_INFO = 
        new MBeanOperationInfo(OP_ENV_STAT,
                               "Get environment statistics.",
                               statParams,
                               "com.sleepycat.je.EnvironmentStats",
                               MBeanOperationInfo.INFO);
    
    private static final MBeanOperationInfo OP_ENV_STAT_STR_INFO = 
        new MBeanOperationInfo(OP_ENV_STAT_STR,