org.apache.hadoop.hbase.client

Class MasterCallable<V>

java.lang.Object

org.apache.hadoop.hbase.client.MasterCallable<V>

Type Parameters:

V - return type

All Implemented Interfaces:

Closeable, AutoCloseable, RetryingCallable<V>

@InterfaceAudience.Private
abstract class MasterCallable<V>
extends Object
implements RetryingCallable<V>, Closeable

A RetryingCallable for Master RPC operations. Implement the #rpcCall method. It will be retried on error. See its javadoc and the javadoc of #call(int). See HBaseAdmin for examples of how this is used. To get at the rpcController that has been created and configured to make this rpc call, use getRpcController(). We are trying to contain all protobuf references including references to rpcController so we don't pollute codebase with protobuf references; keep the protobuf references contained and only present in a few classes rather than all about the code base.

Like RegionServerCallable only in here, we can safely be PayloadCarryingRpcController all the time. This is not possible in the similar RegionServerCallable Callable because it has to deal with Coprocessor Endpoints.

Field Summary

Fields

Modifier and Type	Field and Description
protected ClusterConnection	connection
protected MasterKeepAliveConnection	master
private HBaseRpcController	rpcController

Constructor Summary

Constructors

Constructor and Description
MasterCallable(Connection connection, RpcControllerFactory rpcConnectionFactory)

Method Summary

Modifier and Type	Method and Description
V	call(int callTimeout) Override that changes the Callable.call() Exception from Exception to IOException.
void	close()
String	getExceptionMessageAdditionalDetail() Returns Some details from the implementation that we would like to add to a terminating exception; i.e.
(package private) HBaseRpcController	getRpcController()
private static boolean	isMetaRegion(byte[] regionName)
void	prepare(boolean reload) Prepare by setting up any connections to servers, etc., ahead of call invocation.
protected abstract V	rpcCall() Run the RPC call.
(package private) void	setPriority(byte[] regionName)
(package private) void	setPriority(int priority)
(package private) void	setPriority(TableName tableName)
long	sleep(long pause, int tries) Sleep and retry.
void	throwable(Throwable t, boolean retrying) Called when call throws an exception and we are going to retry; take action to make it so we succeed on next call (clear caches, do relookup of locations, etc.).

Methods inherited from class java.lang.Object

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

Field Detail

connection

protected final ClusterConnection connection

master

protected MasterKeepAliveConnection master

rpcController

private final HBaseRpcController rpcController

Constructor Detail

MasterCallable

MasterCallable(Connection connection,
               RpcControllerFactory rpcConnectionFactory)

Method Detail

prepare

public void prepare(boolean reload)
             throws IOException

Description copied from interface: RetryingCallable

Prepare by setting up any connections to servers, etc., ahead of call invocation. TODO: We call prepare before EVERY call. Seems wrong. FIX!!!!

Specified by:

prepare in interface RetryingCallable<V>

Parameters:

reload - Set this to true if need to requery locations

Throws:

IOException - e

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

throwable

public void throwable(Throwable t,
                      boolean retrying)

Description copied from interface: RetryingCallable

Called when call throws an exception and we are going to retry; take action to make it so we succeed on next call (clear caches, do relookup of locations, etc.).

Specified by:

throwable in interface RetryingCallable<V>

Parameters:

t - throwable which was thrown

retrying - True if we are in retrying mode (we are not in retrying mode when max retries == 1; we ARE in retrying mode if retries > 1 even when we are the last attempt)

getExceptionMessageAdditionalDetail

public String getExceptionMessageAdditionalDetail()

Description copied from interface: RetryingCallable

Returns Some details from the implementation that we would like to add to a terminating exception; i.e. a fatal exception is being thrown ending retries and we might like to add more implementation-specific detail on to the exception being thrown.

Specified by:

getExceptionMessageAdditionalDetail in interface RetryingCallable<V>

sleep

public long sleep(long pause,
                  int tries)

Description copied from interface: RetryingCallable

Sleep and retry.

Specified by:

sleep in interface RetryingCallable<V>

Parameters:

pause - time to pause

tries - amount of tries until till sleep

Returns:

Suggestion on how much to sleep between retries

call

public V call(int callTimeout)
       throws IOException

Override that changes the Callable.call() Exception from Exception to IOException. It also does setup of an rpcController and calls through to the rpcCall() method which callers are expected to implement. If rpcController is an instance of PayloadCarryingRpcController, we will set a timeout on it.

Specified by:

call in interface RetryingCallable<V>

Parameters:

callTimeout - - the time available for this call. 0 for infinite.

Returns:

computed result

Throws:

IOException

rpcCall

protected abstract V rpcCall()
                      throws Exception

Run the RPC call. Implement this method. To get at the rpcController that has been created and configured to make this rpc call, use getRpcController(). We are trying to contain rpcController references so we don't pollute codebase with protobuf references; keep the protobuf references contained and only present in a few classes rather than all about the code base. n

Throws:

Exception

getRpcController

HBaseRpcController getRpcController()

setPriority

void setPriority(int priority)

setPriority

void setPriority(TableName tableName)

setPriority

void setPriority(byte[] regionName)

Parameters:

regionName - RegionName. If hbase:meta, we'll set high priority.

isMetaRegion

private static boolean isMetaRegion(byte[] regionName)