org.apache.activemq.store.jdbc
Class LeaseDatabaseLocker

java.lang.Object
  org.apache.activemq.util.ServiceSupport
      org.apache.activemq.broker.AbstractLocker
          org.apache.activemq.store.jdbc.LeaseDatabaseLocker

All Implemented Interfaces:

Locker, Service

public class LeaseDatabaseLocker
extends AbstractLocker

Represents an exclusive lease on a database to avoid multiple brokers running against the same logical database.

Field Summary

protected DataSource	dataSource
static long	DEFAULT_LOCK_ACQUIRE_SLEEP_INTERVAL
protected long	diffFromCurrentTime
protected String	leaseHolderId
protected int	maxAllowableDiffFromDBTime
protected int	queryTimeout
protected Statements	statements
protected boolean	stopping

Fields inherited from class org.apache.activemq.broker.AbstractLocker

failIfLocked, lockAcquireSleepInterval, name

Constructor Summary

LeaseDatabaseLocker()

Method Summary

void	configure(PersistenceAdapter adapter) Optionally configure the locker with the persistence adapter currently used You can use persistence adapter configuration details like, data directory datasource, etc.
void	doStart()
void	doStop(ServiceStopper stopper)
String	getLeaseHolderId()
long	getLockAcquireSleepInterval()
int	getMaxAllowableDiffFromDBTime()
int	getQueryTimeout()
protected long	initTimeDiff(Connection connection)
boolean	keepAlive() Used by a timer to keep alive the lock.
void	setLeaseHolderId(String leaseHolderId)
void	setLockAcquireSleepInterval(long lockAcquireSleepInterval) set the delay interval in milliseconds between lock acquire attempts
void	setMaxAllowableDiffFromDBTime(int maxAllowableDiffFromDBTime)
void	setQueryTimeout(int queryTimeout)

Methods inherited from class org.apache.activemq.broker.AbstractLocker

setFailIfLocked, setName

Methods inherited from class org.apache.activemq.util.ServiceSupport

addServiceListener, dispose, isStarted, isStopped, isStopping, postStop, preStart, removeServiceListener, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.activemq.Service

start, stop

Field Detail

DEFAULT_LOCK_ACQUIRE_SLEEP_INTERVAL

public static final long DEFAULT_LOCK_ACQUIRE_SLEEP_INTERVAL

See Also:

Constant Field Values

dataSource

protected DataSource dataSource

statements

protected Statements statements

stopping

protected boolean stopping

maxAllowableDiffFromDBTime

protected int maxAllowableDiffFromDBTime

diffFromCurrentTime

protected long diffFromCurrentTime

leaseHolderId

protected String leaseHolderId

queryTimeout

protected int queryTimeout

Constructor Detail

LeaseDatabaseLocker

public LeaseDatabaseLocker()

Method Detail

configure

public void configure(PersistenceAdapter adapter)
               throws IOException

Description copied from interface: Locker

Optionally configure the locker with the persistence adapter currently used You can use persistence adapter configuration details like, data directory datasource, etc. to be used by the locker

Throws:

IOException

doStart

public void doStart()
             throws Exception

Specified by:

doStart in class ServiceSupport

Throws:

Exception

initTimeDiff

protected long initTimeDiff(Connection connection)
                     throws SQLException

Throws:

SQLException

doStop

public void doStop(ServiceStopper stopper)
            throws Exception

Specified by:

doStop in class ServiceSupport

Throws:

Exception

keepAlive

public boolean keepAlive()
                  throws IOException

Description copied from interface: Locker

Used by a timer to keep alive the lock. If the method returns false the broker should be terminated if an exception is thrown, the lock state cannot be determined

Specified by:

keepAlive in interface Locker

Overrides:

keepAlive in class AbstractLocker

Throws:

IOException

getLockAcquireSleepInterval

public long getLockAcquireSleepInterval()

setLockAcquireSleepInterval

public void setLockAcquireSleepInterval(long lockAcquireSleepInterval)

Description copied from interface: Locker

set the delay interval in milliseconds between lock acquire attempts

Specified by:

setLockAcquireSleepInterval in interface Locker

Overrides:

setLockAcquireSleepInterval in class AbstractLocker

Parameters:

lockAcquireSleepInterval - the sleep interval in miliseconds

getQueryTimeout

public int getQueryTimeout()

setQueryTimeout

public void setQueryTimeout(int queryTimeout)

getLeaseHolderId

public String getLeaseHolderId()

setLeaseHolderId

public void setLeaseHolderId(String leaseHolderId)

getMaxAllowableDiffFromDBTime

public int getMaxAllowableDiffFromDBTime()

setMaxAllowableDiffFromDBTime

public void setMaxAllowableDiffFromDBTime(int maxAllowableDiffFromDBTime)