org.apache.cassandra.db.commitlog

Class CommitLog

java.lang.Object

org.apache.cassandra.db.commitlog.CommitLog

All Implemented Interfaces:

CommitLogMBean

public class CommitLog
extends java.lang.Object
implements CommitLogMBean

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	CommitLog.Configuration

Field Summary

Fields

Modifier and Type	Field and Description
CommitLogSegmentManager	allocator
CommitLogArchiver	archiver
static CommitLog	instance
java.lang.String	location

Method Summary

Modifier and Type	Method and Description
int	activeSegments() Used by tests.
ReplayPosition	add(Mutation mutation) Add a Mutation to the commit log.
void	discardCompletedSegments(java.util.UUID cfId, ReplayPosition lowerBound, ReplayPosition upperBound) Modifies the per-CF dirty cursors of any commit log segments for the column family according to the position given.
void	forceRecycleAllSegments() Flushes all dirty CFs, waiting for them to free and recycle any segments they were retaining
void	forceRecycleAllSegments(java.lang.Iterable<java.util.UUID> droppedCfs) Flushes all dirty CFs, waiting for them to free and recycle any segments they were retaining
long	getActiveContentSize()
long	getActiveOnDiskSize()
java.util.Map<java.lang.String,java.lang.Double>	getActiveSegmentCompressionRatios()
java.util.List<java.lang.String>	getActiveSegmentNames()
java.lang.String	getArchiveCommand() Command to execute to archive a commitlog segment.
java.util.List<java.lang.String>	getArchivingSegmentNames()
ReplayPosition	getContext()
java.lang.String	getRestoreCommand() Command to execute to make an archived commitlog live again
java.lang.String	getRestoreDirectories() Directory to scan the recovery files in
long	getRestorePointInTime() Restore mutations created up to and including this timestamp in GMT Format: yyyy:MM:dd HH:mm:ss (2012:04:31 20:43:12) Recovery will continue through the segment when the first client-supplied timestamp greater than this time is encountered, but only mutations less than or equal to this timestamp will be applied.
java.lang.String	getRestorePrecision() get precision of the timestamp used in the restore (MILLISECONDS, MICROSECONDS, ...) to determine if passed the restore point in time.
static boolean	handleCommitError(java.lang.String message, java.lang.Throwable t)
int	recover() Perform recovery on commit logs located in the directory specified by the config file.
int	recover(java.io.File... clogs) Perform recovery on a list of commit log files.
void	recover(java.lang.String path) Perform recovery on a single commit log.
void	requestExtraSync() Preempts the CLExecutor, telling to to sync immediately
void	resetConfiguration() FOR TESTING PURPOSES.
int	resetUnsafe(boolean deleteSegments) FOR TESTING PURPOSES.
int	restartUnsafe() FOR TESTING PURPOSES.
void	shutdownBlocking() Shuts down the threads used by the commit log, blocking until completion.
void	stopUnsafe(boolean deleteSegments) FOR TESTING PURPOSES.
void	sync(boolean syncAllSegments) Forces a disk flush on the commit log files that need it.

Methods inherited from class java.lang.Object

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

Field Detail

instance

public static final CommitLog instance

allocator

public final CommitLogSegmentManager allocator

archiver

public final CommitLogArchiver archiver

location

public final java.lang.String location

Method Detail

recover

public int recover()
            throws java.io.IOException

Perform recovery on commit logs located in the directory specified by the config file.

Returns:

the number of mutations replayed

Throws:

java.io.IOException

recover

public int recover(java.io.File... clogs)
            throws java.io.IOException

Perform recovery on a list of commit log files.

Parameters:

clogs - the list of commit log files to replay

Returns:

the number of mutations replayed

Throws:

java.io.IOException

recover

public void recover(java.lang.String path)
             throws java.io.IOException

Perform recovery on a single commit log.

Specified by:

recover in interface CommitLogMBean

Throws:

java.io.IOException

getContext

public ReplayPosition getContext()

Returns:

a ReplayPosition which, if >= one returned from add(), implies add() was started (but not necessarily finished) prior to this call

forceRecycleAllSegments

public void forceRecycleAllSegments(java.lang.Iterable<java.util.UUID> droppedCfs)

Flushes all dirty CFs, waiting for them to free and recycle any segments they were retaining

forceRecycleAllSegments

public void forceRecycleAllSegments()

Flushes all dirty CFs, waiting for them to free and recycle any segments they were retaining

sync

public void sync(boolean syncAllSegments)

Forces a disk flush on the commit log files that need it. Blocking.

requestExtraSync

public void requestExtraSync()

Preempts the CLExecutor, telling to to sync immediately

add

public ReplayPosition add(Mutation mutation)

Add a Mutation to the commit log.

Parameters:

mutation - the Mutation to add to the log

discardCompletedSegments

public void discardCompletedSegments(java.util.UUID cfId,
                                     ReplayPosition lowerBound,
                                     ReplayPosition upperBound)

Modifies the per-CF dirty cursors of any commit log segments for the column family according to the position given. Discards any commit log segments that are no longer used.

Parameters:

cfId - the column family ID that was flushed

lowerBound - the lowest covered replay position of the flush

lowerBound - the highest covered replay position of the flush

getArchiveCommand

public java.lang.String getArchiveCommand()

Description copied from interface: CommitLogMBean

Command to execute to archive a commitlog segment. Blank to disabled.

Specified by:

getArchiveCommand in interface CommitLogMBean

getRestoreCommand

public java.lang.String getRestoreCommand()

Description copied from interface: CommitLogMBean

Command to execute to make an archived commitlog live again

Specified by:

getRestoreCommand in interface CommitLogMBean

getRestoreDirectories

public java.lang.String getRestoreDirectories()

Description copied from interface: CommitLogMBean

Directory to scan the recovery files in

Specified by:

getRestoreDirectories in interface CommitLogMBean

getRestorePointInTime

public long getRestorePointInTime()

Description copied from interface: CommitLogMBean

Restore mutations created up to and including this timestamp in GMT Format: yyyy:MM:dd HH:mm:ss (2012:04:31 20:43:12) Recovery will continue through the segment when the first client-supplied timestamp greater than this time is encountered, but only mutations less than or equal to this timestamp will be applied.

Specified by:

getRestorePointInTime in interface CommitLogMBean

getRestorePrecision

public java.lang.String getRestorePrecision()

Description copied from interface: CommitLogMBean

get precision of the timestamp used in the restore (MILLISECONDS, MICROSECONDS, ...) to determine if passed the restore point in time.

Specified by:

getRestorePrecision in interface CommitLogMBean

getActiveSegmentNames

public java.util.List<java.lang.String> getActiveSegmentNames()

Specified by:

getActiveSegmentNames in interface CommitLogMBean

Returns:

file names (not full paths) of active commit log segments (segments containing unflushed data)

getArchivingSegmentNames

public java.util.List<java.lang.String> getArchivingSegmentNames()

Specified by:

getArchivingSegmentNames in interface CommitLogMBean

Returns:

Files which are pending for archival attempt. Does NOT include failed archive attempts.

getActiveContentSize

public long getActiveContentSize()

Specified by:

getActiveContentSize in interface CommitLogMBean

Returns:

The size of the mutations in all active commit log segments (uncompressed).

getActiveOnDiskSize

public long getActiveOnDiskSize()

Specified by:

getActiveOnDiskSize in interface CommitLogMBean

Returns:

The space taken on disk by the commit log (compressed).

getActiveSegmentCompressionRatios

public java.util.Map<java.lang.String,java.lang.Double> getActiveSegmentCompressionRatios()

Specified by:

getActiveSegmentCompressionRatios in interface CommitLogMBean

Returns:

A map between active log segments and the compression ratio achieved for each.

shutdownBlocking

public void shutdownBlocking()
                      throws java.lang.InterruptedException

Shuts down the threads used by the commit log, blocking until completion.

Throws:

java.lang.InterruptedException

resetUnsafe

public int resetUnsafe(boolean deleteSegments)
                throws java.io.IOException

FOR TESTING PURPOSES. See CommitLogAllocator.

Returns:

the number of files recovered

Throws:

java.io.IOException

stopUnsafe

public void stopUnsafe(boolean deleteSegments)

FOR TESTING PURPOSES. See CommitLogAllocator.

resetConfiguration

public void resetConfiguration()

FOR TESTING PURPOSES.

restartUnsafe

public int restartUnsafe()
                  throws java.io.IOException

FOR TESTING PURPOSES. See CommitLogAllocator

Throws:

java.io.IOException

activeSegments

public int activeSegments()

Used by tests.

Returns:

the number of active segments (segments with unflushed data in them)

handleCommitError

public static boolean handleCommitError(java.lang.String message,
                                        java.lang.Throwable t)