org.apache.hadoop.hbase.client

Class MasterAddressRefresher

java.lang.Object

org.apache.hadoop.hbase.client.MasterAddressRefresher

All Implemented Interfaces:

Closeable, AutoCloseable

@InterfaceAudience.Private
public class MasterAddressRefresher
extends Object
implements Closeable

Thread safe utility that keeps master end points used by MasterRegistry up to date. This uses the RPC MasterProtos.ClientMetaService.getMasters(org.apache.hbase.thirdparty.com.google.protobuf.RpcController, org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetMastersRequest, org.apache.hbase.thirdparty.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetMastersResponse>) to fetch the latest list of registered masters. By default the refresh happens periodically (configured via PERIODIC_REFRESH_INTERVAL_SECS). The refresh can also be triggered on demand via refreshNow(). To prevent a flood of on-demand refreshes we expect that any attempts two should be spaced at least MIN_SECS_BETWEEN_REFRESHES seconds apart.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	MasterAddressRefresher.RefreshThread Thread that refreshes the master end points until it is interrupted via close().

Field Summary

Fields

Modifier and Type	Field and Description
private static org.slf4j.Logger	LOG
static String	MIN_SECS_BETWEEN_REFRESHES
private static int	MIN_SECS_BETWEEN_REFRESHES_DEFAULT
static String	PERIODIC_REFRESH_INTERVAL_SECS
private static int	PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT
private long	periodicRefreshMs
private ExecutorService	pool
private Object	refreshMasters
private MasterRegistry	registry
private long	timeBetweenRefreshesMs

Constructor Summary

Constructors

Constructor and Description
MasterAddressRefresher(org.apache.hadoop.conf.Configuration conf, MasterRegistry registry)

Method Summary

Modifier and Type	Method and Description
void	close()
(package private) void	refreshNow() Notifies the refresher thread to refresh the configuration.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final org.slf4j.Logger LOG

PERIODIC_REFRESH_INTERVAL_SECS

public static final String PERIODIC_REFRESH_INTERVAL_SECS

See Also:

Constant Field Values

PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT

private static final int PERIODIC_REFRESH_INTERVAL_SECS_DEFAULT

See Also:

Constant Field Values

MIN_SECS_BETWEEN_REFRESHES

public static final String MIN_SECS_BETWEEN_REFRESHES

See Also:

Constant Field Values

MIN_SECS_BETWEEN_REFRESHES_DEFAULT

private static final int MIN_SECS_BETWEEN_REFRESHES_DEFAULT

See Also:

Constant Field Values

pool

private final ExecutorService pool

registry

private final MasterRegistry registry

periodicRefreshMs

private final long periodicRefreshMs

timeBetweenRefreshesMs

private final long timeBetweenRefreshesMs

refreshMasters

private final Object refreshMasters

Constructor Detail

MasterAddressRefresher

MasterAddressRefresher(org.apache.hadoop.conf.Configuration conf,
                       MasterRegistry registry)

Method Detail

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

refreshNow

void refreshNow()

Notifies the refresher thread to refresh the configuration. This does not guarantee a refresh. See class comment for details.