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

CommitLogSegment	activeSegment
CommitLogAllocator	allocator
static int	END_OF_SEGMENT_MARKER
static int	END_OF_SEGMENT_MARKER_SIZE
static CommitLog	instance
static int	SEGMENT_SIZE size of commitlog segments to allocate

Method Summary

int	activeSegments() Used by tests.
void	add(RowMutation rm) Add a RowMutation to the commit log.
void	discardCompletedSegments(java.lang.Integer cfId, ReplayPosition context) Modifies the per-CF dirty cursors of any commit log segments for the column family according to the position given.
void	forceNewSegment() Forces a new segment file to be allocated and activated.
long	getCompletedTasks() Get the number of completed tasks
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	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

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

SEGMENT_SIZE

public static final int SEGMENT_SIZE

size of commitlog segments to allocate

See Also:

Constant Field Values

activeSegment

public CommitLogSegment activeSegment

Method Detail

resetUnsafe

public void resetUnsafe()
                 throws java.io.IOException

FOR TESTING PURPOSES. See CommitLogAllocator.

Throws:

java.io.IOException

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

getContext

public ReplayPosition getContext()

Returns:

the current ReplayPosition of the current segment file

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)
         throws java.io.IOException

Add a RowMutation to the commit log.

Parameters:

rm - the RowMutation to add to the log

Throws:

java.io.IOException

discardCompletedSegments

public void discardCompletedSegments(java.lang.Integer cfId,
                                     ReplayPosition context)
                              throws java.io.IOException

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

Throws:

java.io.IOException

sync

public void sync()
          throws java.io.IOException

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

Throws:

java.io.IOException

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

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

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)

forceNewSegment

public void forceNewSegment()
                     throws java.util.concurrent.ExecutionException,
                            java.lang.InterruptedException

Forces a new segment file to be allocated and activated. Used mainly by truncate.

Throws:

java.util.concurrent.ExecutionException

java.lang.InterruptedException

shutdownBlocking

public void shutdownBlocking()
                      throws java.lang.InterruptedException

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

Throws:

java.lang.InterruptedException