com.sleepycat.je.log

Class VLSNDistributionReader

java.lang.Object

com.sleepycat.je.log.FileReader

com.sleepycat.je.log.DumpFileReader

com.sleepycat.je.log.VLSNDistributionReader

public class VLSNDistributionReader
extends DumpFileReader

This is a debugging utility which implements the unadvertised DbPrintLog -vd option, which displays VLSN distribution in a log. Here's a sample of the output. This is used to analyze log cleaner barrier behavior. ... 3 files file 0xb6 numRepRecords = 9 firstVLSN = 1,093,392 lastVLSN = 1,093,400 file 0xb7 numRepRecords = 4 firstVLSN = 1,093,401 lastVLSN = 1,093,404 ... 3 files file 0xbb numRepRecords = 1 firstVLSN = 1,093,405 lastVLSN = 1,093,405 file 0xbc numRepRecords = 1 firstVLSN = 1,093,406 lastVLSN = 1,093,406 ... 1 files file 0xbe numRepRecords = 1 firstVLSN = 1,093,407 lastVLSN = 1,093,407 file 0xbf numRepRecords = 2 firstVLSN = 1,093,408 lastVLSN = 1,093,409 file 0xc0 numRepRecords = 7 firstVLSN = 1,093,410 lastVLSN = 1,093,416 ... 0 files at end First file: 0x0 Last file: 0xc0

Nested Class Summary

Nested classes/interfaces inherited from class com.sleepycat.je.log.FileReader

FileReader.EOFException, FileReader.ReadWindow

Field Summary

Fields inherited from class com.sleepycat.je.log.DumpFileReader

verbose

Fields inherited from class com.sleepycat.je.log.FileReader

cksumValidator, currentEntryHeader, currentEntryOffset, currentEntryPrevOffset, envImpl, eof, fileManager, forward, logger, nextEntryOffset, startLsn, window

Constructor Summary

Constructors

Constructor and Description
VLSNDistributionReader(EnvironmentImpl envImpl, int readBufferSize, long startLsn, long finishLsn, long endOfFileLsn, boolean verbose, boolean forwards) Create this reader to start at a given LSN.

Method Summary

Modifier and Type	Method and Description
protected boolean	processEntry(ByteBuffer entryBuffer) Count the number of vlsns in the file, along with the first and last vlsn.
void	summarize(boolean csvFormat)

Methods inherited from class com.sleepycat.je.log.DumpFileReader

isTargetEntry, matchEntry, needMatchEntry

Methods inherited from class com.sleepycat.je.log.FileReader

entryIsReplicated, getAndResetNReads, getLastEntrySize, getLastLsn, getLastVlsn, getLogVersion, getNRepeatIteratorReads, getNumRead, handleGapInBackwardsScan, initStartingPosition, makeWindow, readNextEntry, readNextEntryAllowExceptions, setAlwaysValidateChecksum, setBackwardPosition, setForwardPosition, skipData, skipEntry

Methods inherited from class java.lang.Object

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

Constructor Detail

VLSNDistributionReader

public VLSNDistributionReader(EnvironmentImpl envImpl,
                              int readBufferSize,
                              long startLsn,
                              long finishLsn,
                              long endOfFileLsn,
                              boolean verbose,
                              boolean forwards)
                       throws DatabaseException

Create this reader to start at a given LSN.

Throws:

DatabaseException

Method Detail

processEntry

protected boolean processEntry(ByteBuffer entryBuffer)

Count the number of vlsns in the file, along with the first and last vlsn. Display this when the log reader moves to a new file. .

Specified by:

processEntry in class FileReader

Parameters:

entryBuffer - A ByteBuffer that the logrec data and is positioned at the start of the logrec body (i.e., just after the logrec header).

Returns:

true if this entry should be returned to the caller of readNextEntry().

summarize

public void summarize(boolean csvFormat)

Overrides:

summarize in class DumpFileReader