WALPrettyPrinter (Apache HBase 1.7.2 API)

java.lang.Object
- org.apache.hadoop.hbase.wal.WALPrettyPrinter

Direct Known Subclasses:

HLogPrettyPrinter
```
@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

Methods
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
`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
`void`	`setRegionFilter(String region)` sets the region by which output will be filtered
`void`	`setRowFilter(String row)` sets the row key by which output will be filtered
`void`	`setRowPrefixFilter(String rowPrefix)` sets the rowPrefix key prefix by which output will be filtered
`void`	`setSequenceFilter(long sequence)` sets the region by which output will be filtered
`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
    
    Parameters:
    sequence - 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
    
    Parameters:
    region - 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
    
    Parameters:
    row - 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
    
    Parameters:
    rowPrefix - when not null, serves as a filter; only log entries from this rowPrefix 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
    
    Parameters:
    position - 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
    
    Parameters:
    conf - the HBase configuration relevant to this log file
    p - the path of the log file to be read
    
    Throws:
    
    IOException - may be unable to access the configured filesystem or requested file.
  - 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.
    
    Parameters:
    args - Command line arguments
    
    Throws:
    
    IOException - Thrown upon file system errors etc.

Class WALPrettyPrinter

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

WALPrettyPrinter

WALPrettyPrinter

Method Detail

enableValues

disableValues

enableJSON

disableJSON

setSequenceFilter

setTableFilter

setRegionFilter

setRowFilter

setRowPrefixFilter

setOutputOnlyRowKey

setPosition

beginPersistentOutput

endPersistentOutput

processFile

printCell

toStringMap

toStringMap

main

run