Package org.elasticsearch.index.seqno

Class LocalCheckpointTracker

java.lang.Object

org.elasticsearch.index.seqno.LocalCheckpointTracker

public class LocalCheckpointTracker
extends Object

This class generates sequences numbers and keeps track of the so-called "local checkpoint" which is the highest number for which all previous sequence numbers have been processed (inclusive).

Constructor Summary

Constructors

Constructor	Description
LocalCheckpointTracker(long maxSeqNo, long localCheckpoint)	Initialize the local checkpoint service.

Method Summary

Modifier and Type	Method	Description
void	advanceMaxSeqNo(long seqNo)	Marks the provided sequence number as seen and updates the max_seq_no if needed.
long	generateSeqNo()	Issue the next sequence number.
long	getMaxSeqNo()	The maximum sequence number issued so far.
long	getPersistedCheckpoint()	The current persisted checkpoint which can be advanced by markSeqNoAsPersisted(long).
long	getProcessedCheckpoint()	The current checkpoint which can be advanced by markSeqNoAsProcessed(long).
SeqNoStats	getStats(long globalCheckpoint)	constructs a SeqNoStats object, using local state and the supplied global checkpoint This is needed to make sure the persisted local checkpoint and max seq no are consistent
boolean	hasProcessed(long seqNo)	Checks if the given sequence number was marked as processed in this tracker.
void	markSeqNoAsPersisted(long seqNo)	Marks the provided sequence number as persisted and updates the checkpoint if possible.
void	markSeqNoAsProcessed(long seqNo)	Marks the provided sequence number as processed and updates the processed checkpoint if possible.
void	waitForProcessedOpsToComplete(long seqNo)	Waits for all operations up to the provided sequence number to complete.

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalCheckpointTracker

public LocalCheckpointTracker(long maxSeqNo,
                              long localCheckpoint)

Initialize the local checkpoint service. The maxSeqNo should be set to the last sequence number assigned, or SequenceNumbers.NO_OPS_PERFORMED and localCheckpoint should be set to the last known local checkpoint, or SequenceNumbers.NO_OPS_PERFORMED.

Parameters:

maxSeqNo - the last sequence number assigned, or SequenceNumbers.NO_OPS_PERFORMED

localCheckpoint - the last known local checkpoint, or SequenceNumbers.NO_OPS_PERFORMED

Method Detail

generateSeqNo

public long generateSeqNo()

Issue the next sequence number.

Returns:

the next assigned sequence number

advanceMaxSeqNo

public void advanceMaxSeqNo(long seqNo)

Marks the provided sequence number as seen and updates the max_seq_no if needed.

markSeqNoAsProcessed

public void markSeqNoAsProcessed(long seqNo)

Marks the provided sequence number as processed and updates the processed checkpoint if possible.

Parameters:

seqNo - the sequence number to mark as processed

markSeqNoAsPersisted

public void markSeqNoAsPersisted(long seqNo)

Marks the provided sequence number as persisted and updates the checkpoint if possible.

Parameters:

seqNo - the sequence number to mark as persisted

getProcessedCheckpoint

public long getProcessedCheckpoint()

The current checkpoint which can be advanced by markSeqNoAsProcessed(long).

Returns:

the current checkpoint

getPersistedCheckpoint

public long getPersistedCheckpoint()

The current persisted checkpoint which can be advanced by markSeqNoAsPersisted(long).

Returns:

the current persisted checkpoint

getMaxSeqNo

public long getMaxSeqNo()

The maximum sequence number issued so far.

Returns:

the maximum sequence number

getStats

public SeqNoStats getStats(long globalCheckpoint)

constructs a SeqNoStats object, using local state and the supplied global checkpoint This is needed to make sure the persisted local checkpoint and max seq no are consistent

waitForProcessedOpsToComplete

public void waitForProcessedOpsToComplete(long seqNo)
                                   throws InterruptedException

Waits for all operations up to the provided sequence number to complete.

Parameters:

seqNo - the sequence number that the checkpoint must advance to before this method returns

Throws:

InterruptedException - if the thread was interrupted while blocking on the condition

hasProcessed

public boolean hasProcessed(long seqNo)

Checks if the given sequence number was marked as processed in this tracker.