Package org.apache.hadoop.hdfs.server.federation.resolver.order

Class RouterResolver<K,V>

java.lang.Object

org.apache.hadoop.hdfs.server.federation.resolver.order.RouterResolver<K,V>

Type Parameters:

K - The key type of subcluster mapping info queried from Router.

V - The value type of subcluster mapping info queried from Router.

All Implemented Interfaces:

OrderedResolver

Direct Known Subclasses:

AvailableSpaceResolver, LocalResolver

public abstract class RouterResolver<K,V>
extends Object
implements OrderedResolver

The order resolver that depends upon the Router service.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	MIN_UPDATE_PERIOD_KEY	Configuration key to set the minimum time to update subcluster info.

Constructor Summary

Constructors

Constructor	Description
RouterResolver(org.apache.hadoop.conf.Configuration conf, Router routerService)

Method Summary

Modifier and Type	Method	Description
protected abstract String	chooseFirstNamespace(String path, PathLocation loc)	Choose the first namespace from queried subcluster mapping info.
String	getFirstNamespace(String path, PathLocation loc)	Get the first namespace based on this resolver approach.
protected MembershipStore	getMembershipStore()	Get the Membership store.
protected RouterRpcServer	getRpcServer()	Get the Router RPC server.
protected abstract Map<K,V>	getSubclusterInfo(MembershipStore membershipStore)	The implementation for getting desired subcluster mapping info.
protected Map<K,V>	getSubclusterMapping()	Get subcluster mapping info.

Methods inherited from class java.lang.Object

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

Field Details

MIN_UPDATE_PERIOD_KEY

public static final String MIN_UPDATE_PERIOD_KEY

Configuration key to set the minimum time to update subcluster info.

See Also:

• Constant Field Values

Constructor Details

RouterResolver

public RouterResolver(org.apache.hadoop.conf.Configuration conf,
 Router routerService)

Method Details

getFirstNamespace

public String getFirstNamespace(String path,
 PathLocation loc)

Description copied from interface: OrderedResolver

Get the first namespace based on this resolver approach.

Specified by:

getFirstNamespace in interface OrderedResolver

Parameters:

path - Path to check.

loc - Federated location with multiple destinations.

Returns:

First namespace out of the locations.

getSubclusterInfo

protected abstract Map<K,V> getSubclusterInfo(MembershipStore membershipStore)

The implementation for getting desired subcluster mapping info.

Parameters:

membershipStore - Membership store the resolver queried from.

Returns:

The map of desired type info.

chooseFirstNamespace

protected abstract String chooseFirstNamespace(String path,
 PathLocation loc)

Choose the first namespace from queried subcluster mapping info.

Parameters:

path - Path to check.

loc - Federated location with multiple destinations.

Returns:

First namespace out of the locations.

getRpcServer

protected RouterRpcServer getRpcServer()

Get the Router RPC server.

Returns:

Router RPC server. Null if not possible.

getMembershipStore

protected MembershipStore getMembershipStore()

Get the Membership store.

Returns:

Membership store.

getSubclusterMapping

protected Map<K,V> getSubclusterMapping()

Get subcluster mapping info.

Returns:

The map of subcluster info.