org.apache.hadoop.hbase.wal

Class WALPrettyPrinter

java.lang.Object

org.apache.hadoop.hbase.wal.WALPrettyPrinter

@InterfaceAudience.LimitedPrivate(value="Tools")
 @InterfaceStability.Evolving
public class WALPrettyPrinter
extends Object

WALPrettyPrinter prints the contents of a given WAL with a variety of options affecting formatting and extent of content. It targets two usage cases: pretty printing for ease of debugging directly by humans, and JSON output for consumption by monitoring and/or maintenance scripts. It can filter by row, region, or sequence id. It can also toggle output of values.

Constructor Summary

Constructors

Constructor and Description
WALPrettyPrinter() Basic constructor that simply initializes values to reasonable defaults.
WALPrettyPrinter(boolean outputValues, boolean outputJSON, long sequence, Set<String> tableSet, String region, String row, String rowPrefix, boolean outputOnlyRowKey, boolean persistentOutput, PrintStream out) Fully specified constructor.

Method Summary

Modifier and Type	Method and Description
void	beginPersistentOutput() enables output as a single, persistent list.
void	disableJSON() turns JSON output off, and turns on "pretty strings" for human consumption
void	disableValues() turns value output off
void	enableJSON() turns JSON output on
void	enableValues() turns value output on
void	endPersistentOutput() ends output of a single, persistent list.
static void	main(String[] args)
static void	printCell(PrintStream out, Map<String,Object> op, boolean outputValues, boolean outputOnlyRowKey)
void	processFile(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.Path p) reads a log file and outputs its contents, one transaction at a time, as specified by the currently configured options the HBase configuration relevant to this log file the path of the log file to be read may be unable to access the configured filesystem or requested file.
static void	run(String[] args) Pass one or more log file names and formatting options and it will dump out a text version of the contents on stdout.
void	setOutputOnlyRowKey() Option to print the row key only in case you just need the row keys from the WAL
void	setPosition(long position) sets the position to start seeking the WAL file initial position to start seeking the given WAL file
void	setRegionFilter(String region) sets the region by which output will be filtered when not null, serves as a filter; only log entries from this region will be printed
void	setRowFilter(String row) sets the row key by which output will be filtered when not null, serves as a filter; only log entries from this row will be printed
void	setRowPrefixFilter(String rowPrefix) sets the rowPrefix key prefix by which output will be filtered when not null, serves as a filter; only log entries with rows having this prefix will be printed
void	setSequenceFilter(long sequence) sets the region by which output will be filtered when nonnegative, serves as a filter; only log entries with this sequence id will be printed
void	setTableFilter(String tablesWithDelimiter) Sets the tables filter.
static Map<String,Object>	toStringMap(Cell cell)
static Map<String,Object>	toStringMap(Cell cell, boolean printRowKeyOnly, String rowPrefix, String row, boolean outputValues)

Methods inherited from class java.lang.Object

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

Constructor Detail

WALPrettyPrinter

public WALPrettyPrinter()

Basic constructor that simply initializes values to reasonable defaults.

WALPrettyPrinter

public WALPrettyPrinter(boolean outputValues,
                        boolean outputJSON,
                        long sequence,
                        Set<String> tableSet,
                        String region,
                        String row,
                        String rowPrefix,
                        boolean outputOnlyRowKey,
                        boolean persistentOutput,
                        PrintStream out)

Fully specified constructor.

Parameters:

outputValues - when true, enables output of values along with other log information

outputJSON - when true, enables output in JSON format rather than a "pretty string"

sequence - when nonnegative, serves as a filter; only log entries with this sequence id will be printed

tableSet - when non null, serves as a filter. only entries corresponding to tables in the tableSet are printed

region - when not null, serves as a filter; only log entries from this region will be printed

row - when not null, serves as a filter; only log entries from this row will be printed

rowPrefix - when not null, serves as a filter; only log entries with row key having this prefix will be printed

persistentOutput - keeps a single list running for multiple files. if enabled, the endPersistentOutput() method must be used!

out - Specifies an alternative to stdout for the destination of this PrettyPrinter's output.

Method Detail

enableValues

public void enableValues()

turns value output on

disableValues

public void disableValues()

turns value output off

enableJSON

public void enableJSON()

turns JSON output on

disableJSON

public void disableJSON()

turns JSON output off, and turns on "pretty strings" for human consumption

setSequenceFilter

public void setSequenceFilter(long sequence)

sets the region by which output will be filtered when nonnegative, serves as a filter; only log entries with this sequence id will be printed

setTableFilter

public void setTableFilter(String tablesWithDelimiter)

Sets the tables filter. Only log entries for these tables are printed.

Parameters:

tablesWithDelimiter - table names separated with comma.

setRegionFilter

public void setRegionFilter(String region)

sets the region by which output will be filtered when not null, serves as a filter; only log entries from this region will be printed

setRowFilter

public void setRowFilter(String row)

sets the row key by which output will be filtered when not null, serves as a filter; only log entries from this row will be printed

setRowPrefixFilter

public void setRowPrefixFilter(String rowPrefix)

sets the rowPrefix key prefix by which output will be filtered when not null, serves as a filter; only log entries with rows having this prefix will be printed

setOutputOnlyRowKey

public void setOutputOnlyRowKey()

Option to print the row key only in case you just need the row keys from the WAL

setPosition

public void setPosition(long position)

sets the position to start seeking the WAL file initial position to start seeking the given WAL file

beginPersistentOutput

public void beginPersistentOutput()

enables output as a single, persistent list. at present, only relevant in the case of JSON output.

endPersistentOutput

public void endPersistentOutput()

ends output of a single, persistent list. at present, only relevant in the case of JSON output.

processFile

public void processFile(org.apache.hadoop.conf.Configuration conf,
                        org.apache.hadoop.fs.Path p)
                 throws IOException

reads a log file and outputs its contents, one transaction at a time, as specified by the currently configured options the HBase configuration relevant to this log file the path of the log file to be read may be unable to access the configured filesystem or requested file.

Throws:

IOException

printCell

public static void printCell(PrintStream out,
                             Map<String,Object> op,
                             boolean outputValues,
                             boolean outputOnlyRowKey)

toStringMap

public static Map<String,Object> toStringMap(Cell cell,
                                             boolean printRowKeyOnly,
                                             String rowPrefix,
                                             String row,
                                             boolean outputValues)

toStringMap

public static Map<String,Object> toStringMap(Cell cell)

main

public static void main(String[] args)
                 throws IOException

Throws:

IOException

run

public static void run(String[] args)
                throws IOException

Pass one or more log file names and formatting options and it will dump out a text version of the contents on stdout. Command line arguments Thrown upon file system errors etc.

Throws:

IOException