org.apache.manifoldcf.core.lockmanager

Class ZooKeeperLockManager

java.lang.Object

org.apache.manifoldcf.core.lockmanager.BaseLockManager

org.apache.manifoldcf.core.lockmanager.ZooKeeperLockManager

All Implemented Interfaces:

ILockManager

public class ZooKeeperLockManager
extends BaseLockManager
implements ILockManager

The lock manager manages locks across all threads and JVMs and cluster members, using Zookeeper. There should be no more than ONE instance of this class per thread!!! The factory should enforce this.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	ZooKeeperLockManager.ZooKeeperShutdown

Nested classes/interfaces inherited from class org.apache.manifoldcf.core.lockmanager.BaseLockManager

BaseLockManager.LockDescription

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	_rcsid
protected static java.lang.String	anonymousServiceNamePrefix Anonymous service name prefix, to be followed by an integer
protected ManifoldCFConfiguration	cachedConfiguration
protected static java.lang.Integer	connectionPoolLock
protected static java.lang.Integer	ephemeralPoolLocker
protected static ZooKeeperEphemeralNodePool	myEphemeralNodes
protected static LockPool	myZooKeeperLocks
protected static ZooKeeperConnectionPool	pool
protected static java.lang.String	zookeeperConnectStringParameter
protected static java.lang.Integer	zookeeperPoolLocker
protected static java.lang.String	zookeeperSessionTimeoutParameter

Fields inherited from class org.apache.manifoldcf.core.lockmanager.BaseLockManager

activePrefix, anonymousServiceTypeCounter, globalData, globalFlags, localLocks, localSections, myLocks, mySections, serviceDataPrefix, serviceListPrefix, servicePrefix, serviceTypeLockPrefix, threadID, TYPE_READ, TYPE_WRITE, TYPE_WRITENONEX

Constructor Summary

Constructors

Constructor and Description
ZooKeeperLockManager() Constructor

Method Summary

Modifier and Type	Method and Description
protected static java.lang.String	buildServiceTypeActivePath(java.lang.String serviceType, java.lang.String encodedServiceName) Build a zk path for the active node for a specific service of a specific type.
protected static java.lang.String	buildServiceTypeLockPath(java.lang.String serviceType) Build a zk path for the lock for a specific service type.
protected static java.lang.String	buildServiceTypeRegistrationPath(java.lang.String serviceType) Build a zk path for the registration node for a specific service type.
boolean	checkGlobalFlag(java.lang.String flagName) Check the condition of a specified flag.
boolean	checkServiceActive(java.lang.String serviceType, java.lang.String serviceName) Check whether a service is active or not.
boolean	cleanupInactiveService(java.lang.String serviceType, IServiceCleanup cleanup) Clean up any inactive services found.
void	clearGlobalFlag(java.lang.String flagName) Clear a flag.
protected java.lang.String	constructUniqueServiceName(ZooKeeperConnection connection, java.lang.String serviceType) Construct a unique service name given the service type.
int	countActiveServices(java.lang.String serviceType) Count all active services of a given type.
void	endServiceActivity(java.lang.String serviceType, java.lang.String serviceName) End service activity.
protected void	enterServiceRegistryReadLock(ZooKeeperConnection connection, java.lang.String serviceType) Enter service registry read lock
protected void	enterServiceRegistryWriteLock(ZooKeeperConnection connection, java.lang.String serviceType) Enter service registry write lock
protected LockPool	getGlobalLockPool() Override this method to change the nature of global locks.
ManifoldCFConfiguration	getSharedConfiguration() Get the current shared configuration.
protected void	leaveServiceRegistryLock(ZooKeeperConnection connection) Leave service registry lock
static void	main(java.lang.String[] argv)
protected static java.lang.String	makeServiceCounterName(java.lang.String serviceType) Make the service counter name for a service type.
byte[]	readData(java.lang.String resourceName) Read data from a shared data resource.
protected int	readServiceCounter(ZooKeeperConnection connection, java.lang.String serviceCounterName) Read service counter.
java.lang.String	registerServiceBeginServiceActivity(java.lang.String serviceType, java.lang.String serviceName, byte[] initialData, IServiceCleanup cleanup) Register a service and begin service activity.
java.lang.String	registerServiceBeginServiceActivity(java.lang.String serviceType, java.lang.String serviceName, IServiceCleanup cleanup) Register a service and begin service activity.
byte[]	retrieveServiceData(java.lang.String serviceType, java.lang.String serviceName) Retrieve service data for a service.
void	scanServiceData(java.lang.String serviceType, IServiceDataAcceptor dataAcceptor) Scan service data for a service type.
void	setGlobalFlag(java.lang.String flagName) Raise a flag.
void	setSharedConfiguration(java.io.InputStream configurationInputStream) Write shared configuration.
protected static void	shutdownPool() Shutdown the connection pool.
void	updateServiceData(java.lang.String serviceType, java.lang.String serviceName, byte[] serviceData) Set service data for a service.
void	writeData(java.lang.String resourceName, byte[] data) Write data to a shared data resource.
protected void	writeServiceCounter(ZooKeeperConnection connection, java.lang.String serviceCounterName, int counter) Write service counter.

Methods inherited from class org.apache.manifoldcf.core.lockmanager.BaseLockManager

buildServiceListEntry, buildServiceTypeLockName, clear, clearLocks, constructUniqueServiceName, deleteServiceData, enter, enterCriticalSections, enterLocks, enterLocksNoWait, enterNonExWrite, enterNonExWriteCriticalSection, enterNonExWriteLock, enterNonExWriteLockNoWait, enterNonExWriteNoWait, enterNoWait, enterRead, enterReadCriticalSection, enterReadLock, enterReadLockNoWait, enterReadNoWait, enterWrite, enterWriteCriticalSection, enterWriteLock, enterWriteLockNoWait, enterWriteNoWait, getSortedUniqueLocks, leave, leaveCriticalSections, leaveLocks, leaveNonExWrite, leaveNonExWriteCriticalSection, leaveNonExWriteLock, leaveRead, leaveReadCriticalSection, leaveReadLock, leaveWrite, leaveWriteCriticalSection, leaveWriteLock, makeActiveServiceFlagName, makeRegisteredServiceFlagName, makeServiceDataName, readServiceCounter, readServiceData, readServiceName, timedWait, writeServiceCounter, writeServiceData, writeServiceName

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.manifoldcf.core.interfaces.ILockManager

clearLocks, enterCriticalSections, enterLocks, enterLocksNoWait, enterNonExWriteCriticalSection, enterNonExWriteLock, enterNonExWriteLockNoWait, enterReadCriticalSection, enterReadLock, enterReadLockNoWait, enterWriteCriticalSection, enterWriteLock, enterWriteLockNoWait, leaveCriticalSections, leaveLocks, leaveNonExWriteCriticalSection, leaveNonExWriteLock, leaveReadCriticalSection, leaveReadLock, leaveWriteCriticalSection, leaveWriteLock, timedWait

Field Detail

_rcsid

public static final java.lang.String _rcsid

See Also:

Constant Field Values

zookeeperConnectStringParameter

protected static final java.lang.String zookeeperConnectStringParameter

See Also:

Constant Field Values

zookeeperSessionTimeoutParameter

protected static final java.lang.String zookeeperSessionTimeoutParameter

See Also:

Constant Field Values

anonymousServiceNamePrefix

protected static final java.lang.String anonymousServiceNamePrefix

Anonymous service name prefix, to be followed by an integer

See Also:

Constant Field Values

connectionPoolLock

protected static java.lang.Integer connectionPoolLock

pool

protected static ZooKeeperConnectionPool pool

zookeeperPoolLocker

protected static java.lang.Integer zookeeperPoolLocker

myZooKeeperLocks

protected static LockPool myZooKeeperLocks

ephemeralPoolLocker

protected static java.lang.Integer ephemeralPoolLocker

myEphemeralNodes

protected static ZooKeeperEphemeralNodePool myEphemeralNodes

cachedConfiguration

protected ManifoldCFConfiguration cachedConfiguration

Constructor Detail

ZooKeeperLockManager

public ZooKeeperLockManager()
                     throws ManifoldCFException

Constructor

Throws:

ManifoldCFException

Method Detail

registerServiceBeginServiceActivity

public java.lang.String registerServiceBeginServiceActivity(java.lang.String serviceType,
                                                            java.lang.String serviceName,
                                                            IServiceCleanup cleanup)
                                                     throws ManifoldCFException

Register a service and begin service activity. This atomic operation creates a permanent registration entry for a service. If the permanent registration entry already exists, this method will not create it or treat it as an error. This operation also enters the "active" zone for the service. The "active" zone will remain in force until it is canceled, or until the process is interrupted. Ideally, the corresponding endServiceActivity method will be called when the service shuts down. Some ILockManager implementations require that this take place for proper management. If the transient registration already exists, it is treated as an error and an exception will be thrown. If registration will succeed, then this method may call an appropriate IServiceCleanup method to clean up either the current service, or all services on the cluster.

Specified by:

registerServiceBeginServiceActivity in interface ILockManager

Overrides:

registerServiceBeginServiceActivity in class BaseLockManager

Parameters:

serviceType - is the type of service.

serviceName - is the name of the service to register. If null is passed, a transient unique service name will be created, and will be returned to the caller.

cleanup - is called to clean up either the current service, or all services of this type, if no other active service exists. May be null. Local service cleanup is never called if the serviceName argument is null.

Returns:

the actual service name.

Throws:

ManifoldCFException

registerServiceBeginServiceActivity

public java.lang.String registerServiceBeginServiceActivity(java.lang.String serviceType,
                                                            java.lang.String serviceName,
                                                            byte[] initialData,
                                                            IServiceCleanup cleanup)
                                                     throws ManifoldCFException

Register a service and begin service activity. This atomic operation creates a permanent registration entry for a service. If the permanent registration entry already exists, this method will not create it or treat it as an error. This operation also enters the "active" zone for the service. The "active" zone will remain in force until it is canceled, or until the process is interrupted. Ideally, the corresponding endServiceActivity method will be called when the service shuts down. Some ILockManager implementations require that this take place for proper management. If the transient registration already exists, it is treated as an error and an exception will be thrown. If registration will succeed, then this method may call an appropriate IServiceCleanup method to clean up either the current service, or all services on the cluster.

Specified by:

registerServiceBeginServiceActivity in interface ILockManager

Overrides:

registerServiceBeginServiceActivity in class BaseLockManager

Parameters:

serviceType - is the type of service.

serviceName - is the name of the service to register. If null is passed, a transient unique service name will be created, and will be returned to the caller.

initialData - is the initial service data for this service.

cleanup - is called to clean up either the current service, or all services of this type, if no other active service exists. May be null. Local service cleanup is never called if the serviceName argument is null.

Returns:

the actual service name.

Throws:

ManifoldCFException

updateServiceData

public void updateServiceData(java.lang.String serviceType,
                              java.lang.String serviceName,
                              byte[] serviceData)
                       throws ManifoldCFException

Set service data for a service.

Specified by:

updateServiceData in interface ILockManager

Overrides:

updateServiceData in class BaseLockManager

Parameters:

serviceType - is the type of service.

serviceName - is the name of the service.

serviceData - is the data to update to (may be null). This updates the service's transient data (or deletes it). If the service is not active, an exception is thrown.

Throws:

ManifoldCFException

retrieveServiceData

public byte[] retrieveServiceData(java.lang.String serviceType,
                                  java.lang.String serviceName)
                           throws ManifoldCFException

Retrieve service data for a service.

Specified by:

retrieveServiceData in interface ILockManager

Overrides:

retrieveServiceData in class BaseLockManager

Parameters:

serviceType - is the type of service.

serviceName - is the name of the service.

Returns:

the service's transient data.

Throws:

ManifoldCFException

scanServiceData

public void scanServiceData(java.lang.String serviceType,
                            IServiceDataAcceptor dataAcceptor)
                     throws ManifoldCFException

Scan service data for a service type. Only active service data will be considered.

Specified by:

scanServiceData in interface ILockManager

Overrides:

scanServiceData in class BaseLockManager

Parameters:

serviceType - is the type of service.

dataAcceptor - is the object that will be notified of each item of data for each service name found.

Throws:

ManifoldCFException

countActiveServices

public int countActiveServices(java.lang.String serviceType)
                        throws ManifoldCFException

Count all active services of a given type.

Specified by:

countActiveServices in interface ILockManager

Overrides:

countActiveServices in class BaseLockManager

Parameters:

serviceType - is the service type.

Returns:

the count.

Throws:

ManifoldCFException

cleanupInactiveService

public boolean cleanupInactiveService(java.lang.String serviceType,
                                      IServiceCleanup cleanup)
                               throws ManifoldCFException

Clean up any inactive services found. Calling this method will invoke cleanup of one inactive service at a time. If there are no inactive services around, then false will be returned. Note that this method will block whatever service it finds from starting up for the time the cleanup is proceeding. At the end of the cleanup, if successful, the service will be atomically unregistered.

Specified by:

cleanupInactiveService in interface ILockManager

Overrides:

cleanupInactiveService in class BaseLockManager

Parameters:

serviceType - is the service type.

cleanup - is the object to call to clean up an inactive service.

Returns:

true if there were no cleanup operations necessary.

Throws:

ManifoldCFException

endServiceActivity

public void endServiceActivity(java.lang.String serviceType,
                               java.lang.String serviceName)
                        throws ManifoldCFException

End service activity. This operation exits the "active" zone for the service. This must take place using the same ILockManager object that was used to registerServiceBeginServiceActivity() - which implies that it is the same thread.

Specified by:

endServiceActivity in interface ILockManager

Overrides:

endServiceActivity in class BaseLockManager

Parameters:

serviceType - is the type of service.

serviceName - is the name of the service to exit.

Throws:

ManifoldCFException

checkServiceActive

public boolean checkServiceActive(java.lang.String serviceType,
                                  java.lang.String serviceName)
                           throws ManifoldCFException

Check whether a service is active or not. This operation returns true if the specified service is considered active at the moment. Once a service is not active anymore, it can only return to activity by calling beginServiceActivity() once more.

Specified by:

checkServiceActive in interface ILockManager

Overrides:

checkServiceActive in class BaseLockManager

Parameters:

serviceType - is the type of service.

serviceName - is the name of the service to check on.

Returns:

true if the service is considered active.

Throws:

ManifoldCFException

enterServiceRegistryReadLock

protected void enterServiceRegistryReadLock(ZooKeeperConnection connection,
                                            java.lang.String serviceType)
                                     throws ManifoldCFException,
                                            java.lang.InterruptedException

Enter service registry read lock

Throws:

ManifoldCFException

java.lang.InterruptedException

enterServiceRegistryWriteLock

protected void enterServiceRegistryWriteLock(ZooKeeperConnection connection,
                                             java.lang.String serviceType)
                                      throws ManifoldCFException,
                                             java.lang.InterruptedException

Enter service registry write lock

Throws:

ManifoldCFException

java.lang.InterruptedException

leaveServiceRegistryLock

protected void leaveServiceRegistryLock(ZooKeeperConnection connection)
                                 throws ManifoldCFException,
                                        java.lang.InterruptedException

Leave service registry lock

Throws:

ManifoldCFException

java.lang.InterruptedException

constructUniqueServiceName

protected java.lang.String constructUniqueServiceName(ZooKeeperConnection connection,
                                                      java.lang.String serviceType)
                                               throws ManifoldCFException,
                                                      java.lang.InterruptedException

Construct a unique service name given the service type.

Throws:

ManifoldCFException

java.lang.InterruptedException

makeServiceCounterName

protected static java.lang.String makeServiceCounterName(java.lang.String serviceType)

Make the service counter name for a service type.

readServiceCounter

protected int readServiceCounter(ZooKeeperConnection connection,
                                 java.lang.String serviceCounterName)
                          throws ManifoldCFException,
                                 java.lang.InterruptedException

Read service counter.

Throws:

ManifoldCFException

java.lang.InterruptedException

writeServiceCounter

protected void writeServiceCounter(ZooKeeperConnection connection,
                                   java.lang.String serviceCounterName,
                                   int counter)
                            throws ManifoldCFException,
                                   java.lang.InterruptedException

Write service counter.

Throws:

ManifoldCFException

java.lang.InterruptedException

buildServiceTypeLockPath

protected static java.lang.String buildServiceTypeLockPath(java.lang.String serviceType)

Build a zk path for the lock for a specific service type.

buildServiceTypeActivePath

protected static java.lang.String buildServiceTypeActivePath(java.lang.String serviceType,
                                                             java.lang.String encodedServiceName)

Build a zk path for the active node for a specific service of a specific type.

buildServiceTypeRegistrationPath

protected static java.lang.String buildServiceTypeRegistrationPath(java.lang.String serviceType)

Build a zk path for the registration node for a specific service type.

getSharedConfiguration

public ManifoldCFConfiguration getSharedConfiguration()
                                               throws ManifoldCFException

Get the current shared configuration. This configuration is available in common among all nodes, and thus must not be accessed through here for the purpose of finding configuration data that is specific to any one specific node.

Specified by:

getSharedConfiguration in interface ILockManager

Overrides:

getSharedConfiguration in class BaseLockManager

Throws:

ManifoldCFException

setSharedConfiguration

public void setSharedConfiguration(java.io.InputStream configurationInputStream)
                            throws ManifoldCFException

Write shared configuration. Caller closes the input stream.

Throws:

ManifoldCFException

setGlobalFlag

public void setGlobalFlag(java.lang.String flagName)
                   throws ManifoldCFException

Raise a flag. Use this method to assert a condition, or send a global signal. The flag will be reset when the entire system is restarted.

Specified by:

setGlobalFlag in interface ILockManager

Overrides:

setGlobalFlag in class BaseLockManager

Parameters:

flagName - is the name of the flag to set.

Throws:

ManifoldCFException

clearGlobalFlag

public void clearGlobalFlag(java.lang.String flagName)
                     throws ManifoldCFException

Clear a flag. Use this method to clear a condition, or retract a global signal.

Specified by:

clearGlobalFlag in interface ILockManager

Overrides:

clearGlobalFlag in class BaseLockManager

Parameters:

flagName - is the name of the flag to clear.

Throws:

ManifoldCFException

checkGlobalFlag

public boolean checkGlobalFlag(java.lang.String flagName)
                        throws ManifoldCFException

Check the condition of a specified flag.

Specified by:

checkGlobalFlag in interface ILockManager

Overrides:

checkGlobalFlag in class BaseLockManager

Parameters:

flagName - is the name of the flag to check.

Returns:

true if the flag is set, false otherwise.

Throws:

ManifoldCFException

readData

public byte[] readData(java.lang.String resourceName)
                throws ManifoldCFException

Read data from a shared data resource. Use this method to read any existing data, or get a null back if there is no such resource. Note well that this is not necessarily an atomic operation, and it must thus be protected by a lock.

Specified by:

readData in interface ILockManager

Overrides:

readData in class BaseLockManager

Parameters:

resourceName - is the global name of the resource.

Returns:

a byte array containing the data, or null.

Throws:

ManifoldCFException

writeData

public void writeData(java.lang.String resourceName,
                      byte[] data)
               throws ManifoldCFException

Write data to a shared data resource. Use this method to write a body of data into a shared resource. Note well that this is not necessarily an atomic operation, and it must thus be protected by a lock.

Specified by:

writeData in interface ILockManager

Overrides:

writeData in class BaseLockManager

Parameters:

resourceName - is the global name of the resource.

data - is the byte array containing the data. Pass null if you want to delete the resource completely.

Throws:

ManifoldCFException

main

public static void main(java.lang.String[] argv)

getGlobalLockPool

protected LockPool getGlobalLockPool()

Override this method to change the nature of global locks.

Overrides:

getGlobalLockPool in class BaseLockManager

shutdownPool

protected static void shutdownPool()
                            throws ManifoldCFException

Shutdown the connection pool.

Throws:

ManifoldCFException