org.apache.jackrabbit.oak.plugins.document

Class ClusterNodeInfo

java.lang.Object

org.apache.jackrabbit.oak.plugins.document.ClusterNodeInfo

public class ClusterNodeInfo
extends Object

Information about a cluster node.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ClusterNodeInfo.ClusterNodeState
static class	ClusterNodeInfo.RecoverLockState

Field Summary

Fields

Modifier and Type	Field and Description
static String	BROADCAST_ID The broadcast id.
static String	BROADCAST_LISTENER The broadcast listener (host:port).
static boolean	DEFAULT_LEASE_CHECK_DISABLED
static int	DEFAULT_LEASE_DURATION_MILLIS
static int	DEFAULT_LEASE_FAILURE_MARGIN_MILLIS OAK-3398 : default failure margin 20sec before actual lease timeout (note that OAK-3399 / MAX_RETRY_SLEEPS_BEFORE_LEASE_FAILURE eats off another few seconds from this margin, by default 5sec, so the actual default failure-margin is down to 15sec - and that is high-noon!)
static int	DEFAULT_LEASE_UPDATE_INTERVAL_MILLIS OAK-3398 : default update interval 10sec
static String	LAST_WRITTEN_ROOT_REV_KEY The key for the root-revision of the last background write (of unsaved modifications) - that is: the last root-revision written by the instance in case of a clear shutdown or via recovery of another instance in case of a crash
static String	LEASE_END_KEY The end of the lease.
static String	REV_RECOVERY_BY Flag indicating which cluster node is running the recovery.
static String	REV_RECOVERY_LOCK Flag to indicate whether the _lastRev recovery is in progress.
static String	START_TIME_KEY The start time.
static String	STATE The state of the cluster.
protected static String	WORKING_DIR The current working directory.

Method Summary

Modifier and Type	Method and Description
void	dispose()
int	getId()
static ClusterNodeInfo	getInstance(DocumentStore store, org.apache.jackrabbit.oak.plugins.document.RecoveryHandler recoveryHandler, String machineId, String instanceId, int configuredClusterId) Get or create a cluster node info instance for the store.
long	getLeaseEndTime()
long	getLeaseTime()
static ClusterNodeInfo	getReadOnlyInstance(DocumentStore store) Create a cluster node info instance to be utilized for read only access to underlying store.
void	performLeaseCheck() Checks if the lease for this cluster node is still valid, otherwise throws a DocumentStoreException.
boolean	renewLease() Renew the cluster id lease.
void	setInfo(Map<String,String> info) Update the cluster node info.
void	setLeaseFailureHandler(LeaseFailureHandler leaseFailureHandler)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

LEASE_END_KEY

public static final String LEASE_END_KEY

The end of the lease.

See Also:

Constant Field Values

START_TIME_KEY

public static final String START_TIME_KEY

The start time.

See Also:

Constant Field Values

LAST_WRITTEN_ROOT_REV_KEY

public static final String LAST_WRITTEN_ROOT_REV_KEY

The key for the root-revision of the last background write (of unsaved modifications) - that is: the last root-revision written by the instance in case of a clear shutdown or via recovery of another instance in case of a crash

See Also:

Constant Field Values

STATE

public static final String STATE

The state of the cluster. On proper shutdown the state should be cleared.

See Also:

ClusterNodeInfo.ClusterNodeState, Constant Field Values

BROADCAST_ID

public static final String BROADCAST_ID

The broadcast id. If the broadcasting cache is used, a new id is set after startup.

See Also:

Constant Field Values

BROADCAST_LISTENER

public static final String BROADCAST_LISTENER

The broadcast listener (host:port). If the broadcasting cache is used, this is set after startup.

See Also:

Constant Field Values

REV_RECOVERY_LOCK

public static final String REV_RECOVERY_LOCK

Flag to indicate whether the _lastRev recovery is in progress.

See Also:

ClusterNodeInfo.RecoverLockState, Constant Field Values

REV_RECOVERY_BY

public static final String REV_RECOVERY_BY

Flag indicating which cluster node is running the recovery.

See Also:

Constant Field Values

WORKING_DIR

protected static String WORKING_DIR

The current working directory. Note: marked protected non-final for testing purpose only.

DEFAULT_LEASE_DURATION_MILLIS

public static final int DEFAULT_LEASE_DURATION_MILLIS

DEFAULT_LEASE_UPDATE_INTERVAL_MILLIS

public static final int DEFAULT_LEASE_UPDATE_INTERVAL_MILLIS

OAK-3398 : default update interval 10sec

See Also:

Constant Field Values

DEFAULT_LEASE_FAILURE_MARGIN_MILLIS

public static final int DEFAULT_LEASE_FAILURE_MARGIN_MILLIS

OAK-3398 : default failure margin 20sec before actual lease timeout (note that OAK-3399 / MAX_RETRY_SLEEPS_BEFORE_LEASE_FAILURE eats off another few seconds from this margin, by default 5sec, so the actual default failure-margin is down to 15sec - and that is high-noon!)

See Also:

Constant Field Values

DEFAULT_LEASE_CHECK_DISABLED

public static final boolean DEFAULT_LEASE_CHECK_DISABLED

Method Detail

getId

public int getId()

getReadOnlyInstance

public static ClusterNodeInfo getReadOnlyInstance(DocumentStore store)

Create a cluster node info instance to be utilized for read only access to underlying store.

Parameters:

store - the document store.

Returns:

the cluster node info

getInstance

public static ClusterNodeInfo getInstance(DocumentStore store,
                                          org.apache.jackrabbit.oak.plugins.document.RecoveryHandler recoveryHandler,
                                          String machineId,
                                          String instanceId,
                                          int configuredClusterId)

Get or create a cluster node info instance for the store.

Parameters:

store - the document store (for the lease)

recoveryHandler - the recovery handler to call for a clusterId with an expired lease.

machineId - the machine id (null for MAC address)

instanceId - the instance id (null for current working directory)

configuredClusterId - the configured cluster id (or 0 for dynamic assignment)

Returns:

the cluster node info

performLeaseCheck

public void performLeaseCheck()
                       throws DocumentStoreException

Checks if the lease for this cluster node is still valid, otherwise throws a DocumentStoreException. Depending on the LeaseCheckMode this method will not throw the exception immediately when the lease expires. If the mode is set to LeaseCheckMode.LENIENT, then this method will give the lease update thread a last chance of 5 seconds to renew it. This allows the DocumentNodeStore to recover from an expired lease caused by a system put to sleep or a JVM in debug mode.

Throws:

DocumentStoreException - if the lease expired.

renewLease

public boolean renewLease()
                   throws DocumentStoreException

Renew the cluster id lease. This method needs to be called once in a while, to ensure the same cluster id is not re-used by a different instance. The lease is only renewed after 'leaseUpdateInterval' millis since last lease update - default being every 10 sec (this used to be 30sec).

This method will not fail immediately with a DocumentStoreException if the lease expired. It will still try to renew the lease and only fail if performLeaseCheck() decided the lease expired or another cluster node initiated recover for this node.

Returns:

true if the lease was renewed; false otherwise.

Throws:

DocumentStoreException - if the operation failed or the lease expired.

setInfo

public void setInfo(Map<String,String> info)

Update the cluster node info.

Parameters:

info - the map of changes

getLeaseTime

public long getLeaseTime()

getLeaseEndTime

public long getLeaseEndTime()

setLeaseFailureHandler

public void setLeaseFailureHandler(LeaseFailureHandler leaseFailureHandler)

dispose

public void dispose()

toString

public String toString()

Overrides:

toString in class Object