org.apache.hadoop.hbase.favored

Class FavoredNodesManager

java.lang.Object

org.apache.hadoop.hbase.favored.FavoredNodesManager

@InterfaceAudience.Private
public class FavoredNodesManager
extends Object

FavoredNodesManager is responsible for maintaining favored nodes info in internal cache and META table. Its the centralized store for all favored nodes information. All reads and updates should be done through this class. There should only be one instance of FavoredNodesManager in Master. FavoredNodesPlan and favored node information from SnapshotOfRegionAssignmentFromMeta should not be used outside this class (except for tools that only read or fortest cases). All other classes including Favored balancers and FavoredNodeAssignmentHelper should use FavoredNodesManager for any read/write/deletes to favored nodes.

Constructor Summary

Constructors

Constructor and Description
FavoredNodesManager(ClusterInfoProvider provider)

Method Summary

Modifier and Type	Method and Description
void	deleteFavoredNodesForRegion(RegionInfo regionInfo)
void	deleteFavoredNodesForRegions(Collection<RegionInfo> regionInfoList)
static Set<RegionInfo>	filterNonFNApplicableRegions(Collection<RegionInfo> regions) Filter and return regions for which favored nodes is not applicable.
List<ServerName>	getFavoredNodes(RegionInfo regionInfo)
List<ServerName>	getFavoredNodesWithDNPort(RegionInfo regionInfo) This should only be used when sending FN information to the region servers.
Set<RegionInfo>	getRegionsOfFavoredNode(ServerName serverName)
Map<ServerName,List<Integer>>	getReplicaLoad(List<ServerName> servers) Get the replica count for the servers provided.
void	initializeFromMeta()
static boolean	isFavoredNodeApplicable(RegionInfo regionInfo) Favored nodes are not applicable for system tables.
void	updateFavoredNodes(Map<RegionInfo,List<ServerName>> regionFNMap)

Methods inherited from class java.lang.Object

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

Constructor Detail

FavoredNodesManager

public FavoredNodesManager(ClusterInfoProvider provider)

Method Detail

initializeFromMeta

public void initializeFromMeta()
                        throws IOException

Throws:

IOException

getFavoredNodes

public List<ServerName> getFavoredNodes(RegionInfo regionInfo)

isFavoredNodeApplicable

public static boolean isFavoredNodeApplicable(RegionInfo regionInfo)

Favored nodes are not applicable for system tables. We will use this to check before we apply any favored nodes logic on a region.

filterNonFNApplicableRegions

public static Set<RegionInfo> filterNonFNApplicableRegions(Collection<RegionInfo> regions)

Filter and return regions for which favored nodes is not applicable.

Returns:

set of regions for which favored nodes is not applicable

getFavoredNodesWithDNPort

public List<ServerName> getFavoredNodesWithDNPort(RegionInfo regionInfo)

This should only be used when sending FN information to the region servers. Instead of sending the region server port, we use the datanode port. This helps in centralizing the DN port logic in Master. The RS uses the port from the favored node list as hints.

updateFavoredNodes

public void updateFavoredNodes(Map<RegionInfo,List<ServerName>> regionFNMap)
                        throws IOException

Throws:

IOException

getReplicaLoad

public Map<ServerName,List<Integer>> getReplicaLoad(List<ServerName> servers)

Get the replica count for the servers provided.

For each server, replica count includes three counts for primary, secondary and tertiary. If a server is the primary favored node for 10 regions, secondary for 5 and tertiary for 1, then the list would be [10, 5, 1]. If the server is newly added to the cluster is not a favored node for any region, the replica count would be [0, 0, 0].

deleteFavoredNodesForRegion

public void deleteFavoredNodesForRegion(RegionInfo regionInfo)

deleteFavoredNodesForRegions

public void deleteFavoredNodesForRegions(Collection<RegionInfo> regionInfoList)

getRegionsOfFavoredNode

public Set<RegionInfo> getRegionsOfFavoredNode(ServerName serverName)