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

Field Summary

Fields

Modifier and Type	Field and Description
CommitLogSegment	activeSegment
CommitLogAllocator	allocator
CommitLogArchiver	archiver
static int	END_OF_SEGMENT_MARKER
static int	END_OF_SEGMENT_MARKER_SIZE
static CommitLog	instance

Method Summary

Methods

Modifier and Type	Method and Description
int	activeSegments() Used by tests.
void	add(RowMutation rm) Add a RowMutation to the commit log.
void	discardCompletedSegments(java.util.UUID cfId, ReplayPosition context) Modifies the per-CF dirty cursors of any commit log segments for the column family according to the position given.
java.util.List<java.lang.String>	getActiveSegmentNames()
java.util.List<java.lang.String>	getArchivingSegmentNames()
long	getCompletedTasks() Get the number of completed tasks
java.util.concurrent.Future<ReplayPosition>	getContext()
long	getPendingTasks() Get the number of tasks waiting to be executed
long	getTotalCommitlogSize() Get the current size used by all the commitlog segments.
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	resetUnsafe() FOR TESTING PURPOSES.
void	shutdownBlocking() Shuts down the threads used by the commit log, blocking until completion.
void	sync() 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 CommitLogAllocator allocator

archiver

public final CommitLogArchiver archiver

END_OF_SEGMENT_MARKER

public static final int END_OF_SEGMENT_MARKER

See Also:

Constant Field Values

END_OF_SEGMENT_MARKER_SIZE

public static final int END_OF_SEGMENT_MARKER_SIZE

See Also:

Constant Field Values

activeSegment

public CommitLogSegment activeSegment

Method Detail

resetUnsafe

public void resetUnsafe()

FOR TESTING PURPOSES. See CommitLogAllocator.

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 java.util.concurrent.Future<ReplayPosition> getContext()

Returns:

a Future representing a ReplayPosition such that when it is ready, all commitlog tasks enqueued prior to the getContext call will be complete (i.e., appended to the log)

activeSegments

public int activeSegments()

Used by tests.

Returns:

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

add

public void add(RowMutation rm)

Add a RowMutation to the commit log.

Parameters:

rm - the RowMutation to add to the log

discardCompletedSegments

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

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

context - the replay position of the flush

sync

public void sync()

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

getCompletedTasks

public long getCompletedTasks()

Description copied from interface: CommitLogMBean

Get the number of completed tasks

Specified by:

getCompletedTasks in interface CommitLogMBean

Returns:

the number of tasks completed by the commit log executor

See Also:

CommitLogMetrics.completedTasks

getPendingTasks

public long getPendingTasks()

Description copied from interface: CommitLogMBean

Get the number of tasks waiting to be executed

Specified by:

getPendingTasks in interface CommitLogMBean

Returns:

the depth of pending commit log executor queue

See Also:

CommitLogMetrics.pendingTasks

getTotalCommitlogSize

public long getTotalCommitlogSize()

Description copied from interface: CommitLogMBean

Get the current size used by all the commitlog segments.

Specified by:

getTotalCommitlogSize in interface CommitLogMBean

Returns:

the total size occupied by commitlo segments expressed in bytes. (used by MBean)

See Also:

CommitLogMetrics.totalCommitLogSize

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.

shutdownBlocking

public void shutdownBlocking()
                      throws java.lang.InterruptedException

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

Throws:

java.lang.InterruptedException