Package org.apache.hadoop.hbase.regionserver

Class ServerNonceManager

java.lang.Object

org.apache.hadoop.hbase.regionserver.ServerNonceManager

@Private
public class ServerNonceManager
extends Object

Implementation of nonce manager that stores nonces in a hash map and cleans them up after some time; if nonce group/client ID is supplied, nonces are stored by client ID.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	ServerNonceManager.OperationContext

Field Summary

Fields

Modifier and Type	Field	Description
private int	conflictWaitIterationMs	The time to wait in an extremely unlikely case of a conflict with a running op.
private int	deleteNonceGracePeriod
static final String	HASH_NONCE_GRACE_PERIOD_KEY
private static final org.slf4j.Logger	LOG
private ConcurrentHashMap<NonceKey,ServerNonceManager.OperationContext>	nonces	Nonces.
private static final SimpleDateFormat	tsFormat

Constructor Summary

Constructors

Constructor	Description
ServerNonceManager(org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method	Description
void	addMvccToOperationContext(long group, long nonce, long mvcc)	Store the write point in OperationContext when the operation succeed.
private void	cleanUpOldNonces()
ScheduledChore	createCleanupScheduledChore(Stoppable stoppable)	Creates a scheduled chore that is used to clean up old nonces.
void	endOperation(long group, long nonce, boolean success)	Ends the operation started by startOperation.
long	getMvccFromOperationContext(long group, long nonce)	Return the write point of the previous succeed operation.
void	reportOperationFromWal(long group, long nonce, long writeTime)	Reports the operation from WAL during replay.
void	setConflictWaitIterationMs(int conflictWaitIterationMs)
boolean	startOperation(long group, long nonce, Stoppable stoppable)	Starts the operation if operation with such nonce has not already succeeded.

Methods inherited from class java.lang.Object

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

Field Details

HASH_NONCE_GRACE_PERIOD_KEY

public static final String HASH_NONCE_GRACE_PERIOD_KEY

See Also:

• Constant Field Values

LOG

private static final org.slf4j.Logger LOG

conflictWaitIterationMs

private int conflictWaitIterationMs

The time to wait in an extremely unlikely case of a conflict with a running op. Only here so that tests could override it and not wait.

tsFormat

private static final SimpleDateFormat tsFormat

nonces

private ConcurrentHashMap<NonceKey,ServerNonceManager.OperationContext> nonces

Nonces. Approximate overhead per nonce: 64 bytes from hashmap, 32 from two objects (k/v), NK: 16 bytes (2 longs), OC: 8 bytes (1 long) - so, 120 bytes. With 30min expiration time, 5k increments/appends per sec., we'd use approximately 1Gb, which is a realistic worst case. If it's much worse, we could use some sort of memory limit and cleanup.

deleteNonceGracePeriod

private int deleteNonceGracePeriod

Constructor Details

ServerNonceManager

public ServerNonceManager(org.apache.hadoop.conf.Configuration conf)

Method Details

setConflictWaitIterationMs

public void setConflictWaitIterationMs(int conflictWaitIterationMs)

startOperation

public boolean startOperation(long group,
 long nonce,
 Stoppable stoppable)
                       throws InterruptedException

Starts the operation if operation with such nonce has not already succeeded. If the operation is in progress, waits for it to end and checks whether it has succeeded.

Parameters:

group - Nonce group.

nonce - Nonce.

stoppable - Stoppable that terminates waiting (if any) when the server is stopped.

Returns:

true if the operation has not already succeeded and can proceed; false otherwise.

Throws:

InterruptedException

endOperation

public void endOperation(long group,
 long nonce,
 boolean success)

Ends the operation started by startOperation.

Parameters:

group - Nonce group.

nonce - Nonce.

success - Whether the operation has succeeded.

addMvccToOperationContext

public void addMvccToOperationContext(long group,
 long nonce,
 long mvcc)

Store the write point in OperationContext when the operation succeed.

Parameters:

group - Nonce group.

nonce - Nonce.

mvcc - Write point of the succeed operation.

getMvccFromOperationContext

public long getMvccFromOperationContext(long group,
 long nonce)

Return the write point of the previous succeed operation.

Parameters:

group - Nonce group.

nonce - Nonce.

Returns:

write point of the previous succeed operation.

reportOperationFromWal

public void reportOperationFromWal(long group,
 long nonce,
 long writeTime)

Reports the operation from WAL during replay.

Parameters:

group - Nonce group.

nonce - Nonce.

writeTime - Entry write time, used to ignore entries that are too old.

createCleanupScheduledChore

public ScheduledChore createCleanupScheduledChore(Stoppable stoppable)

Creates a scheduled chore that is used to clean up old nonces.

Parameters:

stoppable - Stoppable for the chore.

Returns:

ScheduledChore; the scheduled chore is not started.

cleanUpOldNonces

private void cleanUpOldNonces()