org.apache.hadoop.hbase.client

Class ScannerCallable

java.lang.Object

org.apache.hadoop.hbase.client.RegionServerCallable<Result[]>

org.apache.hadoop.hbase.client.ScannerCallable

All Implemented Interfaces:

Callable<Result[]>, RetryingCallable<Result[]>

Direct Known Subclasses:

ReversedScannerCallable

@InterfaceAudience.Private
public class ScannerCallable
extends RegionServerCallable<Result[]>

Scanner operations such as create, next, etc. Used by ResultScanners made by HTable. Passed to a retrying caller such as RpcRetryingCaller so fails are retried.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	instantiated
protected boolean	isRegionServerRemote
static org.apache.commons.logging.Log	LOG
static String	LOG_SCANNER_ACTIVITY
static String	LOG_SCANNER_LATENCY_CUTOFF
protected ScanMetrics	scanMetrics

Fields inherited from class org.apache.hadoop.hbase.client.RegionServerCallable

connection, location, MIN_WAIT_DEAD_SERVER, row, tableName

Constructor Summary

Constructors

Constructor and Description
ScannerCallable(HConnection connection, byte[] tableName, Scan scan, ScanMetrics scanMetrics) Deprecated. Use ScannerCallable(HConnection, TableName, Scan, ScanMetrics)
ScannerCallable(HConnection connection, TableName tableName, Scan scan, ScanMetrics scanMetrics)

Method Summary

Methods

Modifier and Type	Method and Description
Result[]	call()
protected void	checkIfRegionServerIsRemote() compare the local machine hostname with region server's hostname to decide if hbase client connects to a remote region server
int	getCaching() Get the number of rows that will be fetched on next
HRegionInfo	getHRegionInfo()
protected Scan	getScan()
protected long	openScanner()
void	prepare(boolean reload) Prepare for connection to the server hosting region with row from tablename.
void	setCaching(int caching) Set the number of rows that will be fetched on next
void	setClose() Call this when the next invocation of call should close the scanner

Methods inherited from class org.apache.hadoop.hbase.client.RegionServerCallable

getExceptionMessageAdditionalDetail, getLocation, getRow, getStub, getTableName, setLocation, sleep, throwable

Methods inherited from class java.lang.Object

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

Field Detail

LOG_SCANNER_LATENCY_CUTOFF

public static final String LOG_SCANNER_LATENCY_CUTOFF

See Also:

Constant Field Values

LOG_SCANNER_ACTIVITY

public static final String LOG_SCANNER_ACTIVITY

See Also:

Constant Field Values

LOG

public static final org.apache.commons.logging.Log LOG

instantiated

protected boolean instantiated

scanMetrics

protected ScanMetrics scanMetrics

isRegionServerRemote

protected boolean isRegionServerRemote

Constructor Detail

ScannerCallable

public ScannerCallable(HConnection connection,
               TableName tableName,
               Scan scan,
               ScanMetrics scanMetrics)

Parameters:

connection - which connection

tableName - table callable is on

scan - the scan to execute

scanMetrics - the ScanMetrics to used, if it is null, ScannerCallable won't collect metrics

ScannerCallable

@Deprecated
public ScannerCallable(HConnection connection,
                          byte[] tableName,
                          Scan scan,
                          ScanMetrics scanMetrics)

Deprecated. Use ScannerCallable(HConnection, TableName, Scan, ScanMetrics)

Method Detail

prepare

public void prepare(boolean reload)
             throws IOException

Description copied from class: RegionServerCallable

Prepare for connection to the server hosting region with row from tablename. Does lookup to find region location and hosting server.

Specified by:

prepare in interface RetryingCallable<Result[]>

Overrides:

prepare in class RegionServerCallable<Result[]>

Parameters:

reload - force reload of server location

Throws:

IOException

checkIfRegionServerIsRemote

protected void checkIfRegionServerIsRemote()

compare the local machine hostname with region server's hostname to decide if hbase client connects to a remote region server

call

public Result[] call()
              throws IOException

Throws:

IOException

See Also:

Callable.call()

openScanner

protected long openScanner()
                    throws IOException

Throws:

IOException

getScan

protected Scan getScan()

setClose

public void setClose()

Call this when the next invocation of call should close the scanner

getHRegionInfo

public HRegionInfo getHRegionInfo()

Overrides:

getHRegionInfo in class RegionServerCallable<Result[]>

Returns:

the HRegionInfo for the current region

getCaching

public int getCaching()

Get the number of rows that will be fetched on next

Returns:

the number of rows for caching

setCaching

public void setCaching(int caching)

Set the number of rows that will be fetched on next

Parameters:

caching - the number of rows for caching