org.apache.hadoop.hbase.regionserver.wal

Interface WALActionsListener

All Known Implementing Classes:

MetricsWAL, ReplicationSourceWALActionListener

@InterfaceAudience.Private
public interface WALActionsListener

Get notification of WAL events. The invocations are inline so make sure your implementation is fast else you'll slow hbase.

Method Summary

Modifier and Type	Method and Description
default void	logCloseRequested() The WAL is about to close.
default void	logRollRequested(boolean tooFewReplicas) A request was made that the WAL be rolled.
default void	postAppend(long entryLen, long elapsedTimeMillis, WALKey logKey, WALEdit logEdit) For notification post append to the writer.
default void	postLogArchive(org.apache.hadoop.fs.Path oldPath, org.apache.hadoop.fs.Path newPath) The WAL has been archived.
default void	postLogRoll(org.apache.hadoop.fs.Path oldPath, org.apache.hadoop.fs.Path newPath) The WAL has been rolled.
default void	postSync(long timeInNanos, int handlerSyncs) For notification post writer sync.
default void	preLogArchive(org.apache.hadoop.fs.Path oldPath, org.apache.hadoop.fs.Path newPath) The WAL is going to be archived.
default void	preLogRoll(org.apache.hadoop.fs.Path oldPath, org.apache.hadoop.fs.Path newPath) The WAL is going to be rolled.
default void	visitLogEntryBeforeWrite(RegionInfo info, WALKey logKey, WALEdit logEdit) Called before each write.
default void	visitLogEntryBeforeWrite(WALKey logKey, WALEdit logEdit)

Method Detail

preLogRoll

default void preLogRoll(org.apache.hadoop.fs.Path oldPath,
                        org.apache.hadoop.fs.Path newPath)
                 throws IOException

The WAL is going to be rolled. The oldPath can be null if this is the first log file from the regionserver.

Parameters:

oldPath - the path to the old wal

newPath - the path to the new wal

Throws:

IOException

postLogRoll

default void postLogRoll(org.apache.hadoop.fs.Path oldPath,
                         org.apache.hadoop.fs.Path newPath)
                  throws IOException

The WAL has been rolled. The oldPath can be null if this is the first log file from the regionserver.

Parameters:

oldPath - the path to the old wal

newPath - the path to the new wal

Throws:

IOException

preLogArchive

default void preLogArchive(org.apache.hadoop.fs.Path oldPath,
                           org.apache.hadoop.fs.Path newPath)
                    throws IOException

The WAL is going to be archived.

Parameters:

oldPath - the path to the old wal

newPath - the path to the new wal

Throws:

IOException

postLogArchive

default void postLogArchive(org.apache.hadoop.fs.Path oldPath,
                            org.apache.hadoop.fs.Path newPath)
                     throws IOException

The WAL has been archived.

Parameters:

oldPath - the path to the old wal

newPath - the path to the new wal

Throws:

IOException

logRollRequested

default void logRollRequested(boolean tooFewReplicas)

A request was made that the WAL be rolled.

logCloseRequested

default void logCloseRequested()

The WAL is about to close.

visitLogEntryBeforeWrite

default void visitLogEntryBeforeWrite(RegionInfo info,
                                      WALKey logKey,
                                      WALEdit logEdit)

Called before each write.

visitLogEntryBeforeWrite

default void visitLogEntryBeforeWrite(WALKey logKey,
                                      WALEdit logEdit)
                               throws IOException

Parameters:

logKey -

logEdit - TODO: Retire this in favor of visitLogEntryBeforeWrite(RegionInfo, WALKey, WALEdit) It only exists to get scope when replicating. Scope should be in the WALKey and not need us passing in a htd.

Throws:

IOException - If failed to parse the WALEdit

postAppend

default void postAppend(long entryLen,
                        long elapsedTimeMillis,
                        WALKey logKey,
                        WALEdit logEdit)
                 throws IOException

For notification post append to the writer. Used by metrics system at least. TODO: Combine this with above.

Parameters:

entryLen - approx length of cells in this append.

elapsedTimeMillis - elapsed time in milliseconds.

logKey - A WAL key

logEdit - A WAL edit containing list of cells.

Throws:

IOException - if any network or I/O error occurred

postSync

default void postSync(long timeInNanos,
                      int handlerSyncs)

For notification post writer sync. Used by metrics system at least.

Parameters:

timeInNanos - How long the filesystem sync took in nanoseconds.

handlerSyncs - How many sync handler calls were released by this call to filesystem sync.