org.apache.ignite.internal.pagemem.wal

Interface IgniteWriteAheadLogManager

All Superinterfaces:

GridCacheSharedManager, IgniteChangeGlobalStateSupport

All Known Implementing Classes:

FileWriteAheadLogManager

public interface IgniteWriteAheadLogManager
extends GridCacheSharedManager, IgniteChangeGlobalStateSupport

Method Summary

Modifier and Type	Method and Description
long	currentSegment()
boolean	disabled(int grpId) Checks WAL disabled for cache group.
WALPointer	flush(WALPointer ptr, boolean explicitFsync) Makes sure that all log entries written to the log up until the specified pointer are actually written to the underlying storage.
boolean	isAlwaysWriteFullPages()
boolean	isFullSync()
long	lastArchivedSegment()
long	lastCompactedSegment()
WALPointer	lastWritePointer() Get last written pointer.
WALPointer	log(WALRecord entry) Appends the given log entry to the write-ahead log.
WALPointer	log(WALRecord entry, RolloverType rolloverType) Appends the given log entry to the write-ahead log.
void	notchLastCheckpointPtr(WALPointer ptr) Notifies this about latest checkpoint pointer.
WALRecord	read(WALPointer ptr) Reads WAL record by the specified pointer.
void	release(WALPointer start) Invoke this method to release WAL history since provided pointer that was previously reserved.
WALIterator	replay(WALPointer start) Invoke this method to iterate over the written log entries.
WALIterator	replay(WALPointer start, @Nullable IgniteBiPredicate<WALRecord.RecordType,WALPointer> recordDeserializeFilter) Invoke this method to iterate over the written log entries.
boolean	reserve(WALPointer start) Invoke this method to reserve WAL history since provided pointer and prevent it's deletion.
boolean	reserved(WALPointer ptr) Checks if WAL segment is under lock or reserved
int	reserved(WALPointer low, WALPointer high) Checks if WAL segments is under lock or reserved.
void	resumeLogging(WALPointer lastWrittenPtr) Resumes logging after start.
long	segmentSize(long idx) Getting local WAL segment size.
int	serializerVersion()
int	truncate(@Nullable WALPointer high) Gives a hint to WAL manager to clear entries logged before the given pointer.
int	walArchiveSegments()

Methods inherited from interface org.apache.ignite.internal.processors.cache.GridCacheSharedManager

onDisconnected, onKernalStart, onKernalStop, onReconnected, printMemoryStats, start, stop

Methods inherited from interface org.apache.ignite.internal.processors.cluster.IgniteChangeGlobalStateSupport

onActivate, onDeActivate

Method Detail

isAlwaysWriteFullPages

boolean isAlwaysWriteFullPages()

Returns:

true If we have to always write full pages.

isFullSync

boolean isFullSync()

Returns:

true if WAL will perform fair syncs on fsync call.

serializerVersion

int serializerVersion()

Returns:

Current serializer version.

resumeLogging

void resumeLogging(WALPointer lastWrittenPtr)
            throws IgniteCheckedException

Resumes logging after start. When WAL manager is started, it will skip logging any updates until this method is called to avoid logging changes induced by the state restore procedure.

Throws:

IgniteCheckedException - If fails.

log

WALPointer log(WALRecord entry)
        throws IgniteCheckedException,
               StorageException

Appends the given log entry to the write-ahead log.

Parameters:

entry - Entry to log.

Returns:

WALPointer that may be passed to flush(WALPointer, boolean) method to make sure the record is written to the log.

Throws:

IgniteCheckedException - If failed to construct log entry.

StorageException - If IO error occurred while writing log entry.

log

WALPointer log(WALRecord entry,
               RolloverType rolloverType)
        throws IgniteCheckedException,
               StorageException

Appends the given log entry to the write-ahead log. If entry logging leads to rollover, caller can specify whether to write the entry to the current segment or to th next one.

Parameters:

entry - Entry to log.

rolloverType - Rollover type.

Returns:

WALPointer that may be passed to flush(WALPointer, boolean) method to make sure the record is written to the log.

Throws:

IgniteCheckedException - If failed to construct log entry.

StorageException - If IO error occurred while writing log entry.

See Also:

RolloverType

flush

WALPointer flush(WALPointer ptr,
                 boolean explicitFsync)
          throws IgniteCheckedException,
                 StorageException

Makes sure that all log entries written to the log up until the specified pointer are actually written to the underlying storage.

Parameters:

ptr - Optional pointer to write. If null, will sync up to the latest record.

explicitFsync - If true, data will be synced to the storage device on hardware level.

Returns:

Last WAL position which was flushed to WAL segment file. May be greater than or equal to a ptr. May be null, it means nothing has been flushed.

Throws:

IgniteCheckedException - If failed to write.

StorageException - If IO exception occurred during the write. If an exception is thrown from this method, the WAL will be invalidated and the node will be stopped.

read

WALRecord read(WALPointer ptr)
        throws IgniteCheckedException,
               StorageException

Reads WAL record by the specified pointer.

Parameters:

ptr - WAL pointer.

Returns:

WAL record.

Throws:

IgniteCheckedException - If failed to read.

StorageException - If IO error occurred while reading WAL entries.

replay

WALIterator replay(WALPointer start)
            throws IgniteCheckedException,
                   StorageException

Invoke this method to iterate over the written log entries.

Parameters:

start - Optional WAL pointer from which to start iteration.

Returns:

Records iterator.

Throws:

IgniteException - If failed to start iteration.

StorageException - If IO error occurred while reading WAL entries.

IgniteCheckedException

replay

WALIterator replay(WALPointer start,
                   @Nullable
                   @Nullable IgniteBiPredicate<WALRecord.RecordType,WALPointer> recordDeserializeFilter)
            throws IgniteCheckedException,
                   StorageException

Invoke this method to iterate over the written log entries.

Parameters:

start - Optional WAL pointer from which to start iteration.

recordDeserializeFilter - Specify a filter to skip WAL records. Those records will not be explicitly deserialized.

Returns:

Records iterator.

Throws:

IgniteException - If failed to start iteration.

StorageException - If IO error occurred while reading WAL entries.

IgniteCheckedException

reserve

boolean reserve(WALPointer start)

Invoke this method to reserve WAL history since provided pointer and prevent it's deletion.

Parameters:

start - WAL pointer.

release

void release(WALPointer start)
      throws IgniteCheckedException

Invoke this method to release WAL history since provided pointer that was previously reserved.

Parameters:

start - WAL pointer.

Throws:

IgniteException - If failed to release.

IgniteCheckedException

truncate

int truncate(@Nullable
             @Nullable WALPointer high)

Gives a hint to WAL manager to clear entries logged before the given pointer. If entries are needed for binary recovery, they will not be affected. Some entries may be reserved eg for historical rebalance and they also will not be affected.

Parameters:

high - Upper border to which WAL segments will be deleted.

Returns:

Number of deleted WAL segments.

notchLastCheckpointPtr

void notchLastCheckpointPtr(WALPointer ptr)

Notifies this about latest checkpoint pointer.

Current implementations, in fact, react by keeping all WAL segments uncompacted starting from index prior to the index of ptr. Compaction implies filtering out physical records and ZIP compression.

Parameters:

ptr - Pointer for which it is safe to compact the log.

currentSegment

long currentSegment()

Returns:

Current segment index.

walArchiveSegments

int walArchiveSegments()

Returns:

Total number of segments in the WAL archive.

lastArchivedSegment

long lastArchivedSegment()

Returns:

Last archived segment index.

lastCompactedSegment

long lastCompactedSegment()

Returns:

Last compacted segment index.

reserved

boolean reserved(WALPointer ptr)

Checks if WAL segment is under lock or reserved

Parameters:

ptr - Pointer to check.

Returns:

True if given pointer is located in reserved segment.

reserved

int reserved(WALPointer low,
             WALPointer high)

Checks if WAL segments is under lock or reserved.

Parameters:

low - Pointer since which WAL is locked or reserved. If null, checks from the oldest segment.

high - Pointer for which WAL is locked or reserved.

Returns:

Number of reserved WAL segments.

disabled

boolean disabled(int grpId)

Checks WAL disabled for cache group.

Parameters:

grpId - Group id.

segmentSize

long segmentSize(long idx)

Getting local WAL segment size.

Parameters:

idx - Absolute segment index.

Returns:

Segment size, 0 if size is unknown.

lastWritePointer

WALPointer lastWritePointer()

Get last written pointer.

Returns:

Last written pointer.