org.apache.hadoop.hbase
Class HMsg

java.lang.Object
  org.apache.hadoop.hbase.HMsg

All Implemented Interfaces:

Writable

public class HMsg
extends Object
implements Writable

HMsg is for communicating instructions between the HMaster and the HRegionServers.

Field Summary

static byte	MSG_CALL_SERVER_STARTUP Region server is unknown to master.
static byte	MSG_REGION_CLOSE Stop serving the specified region
static byte	MSG_REGION_CLOSE_WITHOUT_REPORT Stop serving the specified region and don't report back that it's closed
static byte	MSG_REGION_OPEN Start serving the specified region
static byte	MSG_REGIONSERVER_STOP Master tells region server to stop
static byte	MSG_REPORT_CLOSE region server is no longer serving the specified region
static byte	MSG_REPORT_EXITING region server is shutting down note that this message is followed by MSG_REPORT_CLOSE messages for each region the region server was serving.
static byte	MSG_REPORT_OPEN region server is now serving the specified region
static byte	MSG_REPORT_SPLIT region server split the region associated with this message.

Constructor Summary

HMsg()
Default constructor.

HMsg(byte msg)
Construct a message with an empty HRegionInfo

HMsg(byte msg, HRegionInfo info)
Construct a message with the specified message code and HRegionInfo

Method Summary

byte	getMsg() Accessor
HRegionInfo	getRegionInfo() Accessor
void	readFields(DataInput in) Deserialize the fields of this object from in.
String	toString()
void	write(DataOutput out) Serialize the fields of this object to out.

Methods inherited from class java.lang.Object

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

Field Detail

MSG_REGION_OPEN

public static final byte MSG_REGION_OPEN

Start serving the specified region

See Also:

Constant Field Values

MSG_REGION_CLOSE

public static final byte MSG_REGION_CLOSE

Stop serving the specified region

See Also:

Constant Field Values

MSG_CALL_SERVER_STARTUP

public static final byte MSG_CALL_SERVER_STARTUP

Region server is unknown to master. Restart

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Constant Field Values

MSG_REGIONSERVER_STOP

public static final byte MSG_REGIONSERVER_STOP

Master tells region server to stop

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Constant Field Values

MSG_REGION_CLOSE_WITHOUT_REPORT

public static final byte MSG_REGION_CLOSE_WITHOUT_REPORT

Stop serving the specified region and don't report back that it's closed

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Constant Field Values

MSG_REPORT_OPEN

public static final byte MSG_REPORT_OPEN

region server is now serving the specified region

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Constant Field Values

MSG_REPORT_CLOSE

public static final byte MSG_REPORT_CLOSE

region server is no longer serving the specified region

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Constant Field Values

MSG_REPORT_SPLIT

public static final byte MSG_REPORT_SPLIT

region server split the region associated with this message. note that this message is immediately followed by two MSG_REPORT_OPEN messages, one for each of the new regions resulting from the split

See Also:

Constant Field Values

MSG_REPORT_EXITING

public static final byte MSG_REPORT_EXITING

region server is shutting down note that this message is followed by MSG_REPORT_CLOSE messages for each region the region server was serving.

See Also:

Constant Field Values

Constructor Detail

HMsg

public HMsg()

Default constructor. Used during deserialization

HMsg

public HMsg(byte msg)

Construct a message with an empty HRegionInfo

Parameters:

msg - - message code

HMsg

public HMsg(byte msg,
            HRegionInfo info)

Construct a message with the specified message code and HRegionInfo

Parameters:

msg - - message code

info - - HRegionInfo

Method Detail

getMsg

public byte getMsg()

Accessor

Returns:

message code

getRegionInfo

public HRegionInfo getRegionInfo()

Accessor

Returns:

HRegionInfo

toString

public String toString()

Overrides:

toString in class Object

write

public void write(DataOutput out)
           throws IOException

Serialize the fields of this object to out.

Specified by:

write in interface Writable

Parameters:

out - DataOuput to serialize this object into.

Throws:

IOException

readFields

public void readFields(DataInput in)
                throws IOException

Deserialize the fields of this object from in.

For efficiency, implementations should attempt to re-use storage in the existing object where possible.

Specified by:

readFields in interface Writable

Parameters:

in - DataInput to deseriablize this object from.

Throws:

IOException