Package org.apache.hadoop.hbase.favored

Class FavoredNodeAssignmentHelper

java.lang.Object

org.apache.hadoop.hbase.favored.FavoredNodeAssignmentHelper

@Private
public class FavoredNodeAssignmentHelper
extends Object

Helper class for FavoredNodeLoadBalancer that has all the intelligence for racks, meta scans, etc. Instantiated by the FavoredNodeLoadBalancer when needed (from within calls like FavoredNodeLoadBalancer.randomAssignment(RegionInfo, List)). All updates to favored nodes should only be done from FavoredNodesManager and not through this helper class (except for tests).

Field Summary

Fields

Modifier and Type	Field	Description
static final short	FAVORED_NODES_NUM
static final byte[]	FAVOREDNODES_QUALIFIER
private static final org.slf4j.Logger	LOG
static final short	MAX_ATTEMPTS_FN_GENERATION
private RackManager	rackManager
private Map<String,List<ServerName>>	rackToRegionServerMap
private Map<String,String>	regionServerToRackMap
private List<ServerName>	servers
private List<String>	uniqueRackList

Constructor Summary

Constructors

Constructor	Description
FavoredNodeAssignmentHelper(List<ServerName> servers, org.apache.hadoop.conf.Configuration conf)
FavoredNodeAssignmentHelper(List<ServerName> servers, RackManager rackManager)

Method Summary

Modifier and Type	Method	Description
boolean	canPlaceFavoredNodes()
private Map<RegionInfo,List<ServerName>>	generateFavoredNodes(Map<RegionInfo,ServerName> primaryRSMap)
List<ServerName>	generateFavoredNodes(RegionInfo hri)
Map<RegionInfo,List<ServerName>>	generateFavoredNodesRoundRobin(Map<ServerName,List<RegionInfo>> assignmentMap, List<RegionInfo> regions)
ServerName	generateMissingFavoredNode(List<ServerName> favoredNodes)
ServerName	generateMissingFavoredNode(List<ServerName> favoredNodes, List<ServerName> excludeNodes)
private ServerName	generateMissingFavoredNodeMultiRack(List<ServerName> favoredNodes)
private ServerName	generateMissingFavoredNodeMultiRack(List<ServerName> favoredNodes, List<ServerName> excludeNodes)
private ServerName	generateMissingFavoredNodeSingleRack(List<ServerName> favoredNodes, List<ServerName> excludeNodes)
static byte[]	getFavoredNodes(List<ServerName> serverAddrList)	Returns PB'ed bytes of HBaseProtos.FavoredNodes generated by the server list.
static String	getFavoredNodesAsString(List<ServerName> nodes)
static ServerName[]	getFavoredNodesList(byte[] favoredNodes)	Convert PB bytes to ServerName.
(package private) String	getOneRandomRack(Set<String> skipRackSet)
private ServerName	getOneRandomServer(String rack)
protected ServerName	getOneRandomServer(String rack, Set<ServerName> skipServerSet)	Gets a random server from the specified rack and skips anything specified.
private String	getRackOfServer(ServerName sn)
ServerName[]	getSecondaryAndTertiary(RegionInfo regionInfo, ServerName primaryRS)
private List<ServerName>	getServersFromRack(String rack)
private int	getTotalNumberOfRacks()
void	initialize()
private static Put	makePut(RegionInfo regionInfo, List<ServerName> favoredNodeList)
private Map<ServerName,Set<RegionInfo>>	mapRSToPrimaries(Map<RegionInfo,ServerName> primaryRSMap)
private ServerName[]	multiRackCase(ServerName primaryRS, String primaryRack)	Place secondary and tertiary nodes in a multi rack case.
private ServerName[]	multiRackCaseWithRestrictions(Map<ServerName,Set<RegionInfo>> serverToPrimaries, Map<RegionInfo,ServerName[]> secondaryAndTertiaryMap, String primaryRack, ServerName primaryRS, RegionInfo regionInfo)
void	placePrimaryRSAsRoundRobin(Map<ServerName,List<RegionInfo>> assignmentMap, Map<RegionInfo,ServerName> primaryRSMap, List<RegionInfo> regions)
Map<RegionInfo,ServerName[]>	placeSecondaryAndTertiaryRS(Map<RegionInfo,ServerName> primaryRSMap)
Map<RegionInfo,ServerName[]>	placeSecondaryAndTertiaryWithRestrictions(Map<RegionInfo,ServerName> primaryRSMap)	For regions that share the primary, avoid placing the secondary and tertiary on a same RS.
private ServerName[]	singleRackCase(RegionInfo regionInfo, ServerName primaryRS, String primaryRack)
static void	updateMetaWithFavoredNodesInfo(Map<RegionInfo,List<ServerName>> regionToFavoredNodes, org.apache.hadoop.conf.Configuration conf)	Update meta table with favored nodes info
static void	updateMetaWithFavoredNodesInfo(Map<RegionInfo,List<ServerName>> regionToFavoredNodes, Connection connection)	Update meta table with favored nodes info

Methods inherited from class java.lang.Object

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

Field Details

LOG

private static final org.slf4j.Logger LOG

rackManager

private RackManager rackManager

rackToRegionServerMap

private Map<String,List<ServerName>> rackToRegionServerMap

uniqueRackList

private List<String> uniqueRackList

regionServerToRackMap

private Map<String,String> regionServerToRackMap

servers

private List<ServerName> servers

FAVOREDNODES_QUALIFIER

public static final byte[] FAVOREDNODES_QUALIFIER

FAVORED_NODES_NUM

public static final short FAVORED_NODES_NUM

See Also:

• Constant Field Values

MAX_ATTEMPTS_FN_GENERATION

public static final short MAX_ATTEMPTS_FN_GENERATION

See Also:

• Constant Field Values

Constructor Details

FavoredNodeAssignmentHelper

public FavoredNodeAssignmentHelper(List<ServerName> servers,
 org.apache.hadoop.conf.Configuration conf)

FavoredNodeAssignmentHelper

public FavoredNodeAssignmentHelper(List<ServerName> servers,
 RackManager rackManager)

Method Details

initialize

public void initialize()

updateMetaWithFavoredNodesInfo

public static void updateMetaWithFavoredNodesInfo(Map<RegionInfo,List<ServerName>> regionToFavoredNodes,
 Connection connection)
                                           throws IOException

Update meta table with favored nodes info

Parameters:

regionToFavoredNodes - map of RegionInfo's to their favored nodes

connection - connection to be used

Throws:

IOException

updateMetaWithFavoredNodesInfo

public static void updateMetaWithFavoredNodesInfo(Map<RegionInfo,List<ServerName>> regionToFavoredNodes,
 org.apache.hadoop.conf.Configuration conf)
                                           throws IOException

Update meta table with favored nodes info

Throws:

IOException

makePut

private static Put makePut(RegionInfo regionInfo,
 List<ServerName> favoredNodeList)
                    throws IOException

Throws:

IOException

getFavoredNodesList

public static ServerName[] getFavoredNodesList(byte[] favoredNodes)
                                        throws IOException

Convert PB bytes to ServerName.

Parameters:

favoredNodes - The PB'ed bytes of favored nodes

Returns:

the array of ServerName for the byte array of favored nodes.

Throws:

IOException

getFavoredNodes

public static byte[] getFavoredNodes(List<ServerName> serverAddrList)

Returns PB'ed bytes of HBaseProtos.FavoredNodes generated by the server list.

placePrimaryRSAsRoundRobin

public void placePrimaryRSAsRoundRobin(Map<ServerName,List<RegionInfo>> assignmentMap,
 Map<RegionInfo,ServerName> primaryRSMap,
 List<RegionInfo> regions)

placeSecondaryAndTertiaryRS

public Map<RegionInfo,ServerName[]> placeSecondaryAndTertiaryRS(Map<RegionInfo,ServerName> primaryRSMap)

getSecondaryAndTertiary

public ServerName[] getSecondaryAndTertiary(RegionInfo regionInfo,
 ServerName primaryRS)
                                     throws IOException

Throws:

IOException

mapRSToPrimaries

private Map<ServerName,Set<RegionInfo>> mapRSToPrimaries(Map<RegionInfo,ServerName> primaryRSMap)

placeSecondaryAndTertiaryWithRestrictions

public Map<RegionInfo,ServerName[]> placeSecondaryAndTertiaryWithRestrictions(Map<RegionInfo,ServerName> primaryRSMap)

For regions that share the primary, avoid placing the secondary and tertiary on a same RS. Used for generating new assignments for the primary/secondary/tertiary RegionServers

Returns:

the map of regions to the servers the region-files should be hosted on

multiRackCaseWithRestrictions

private ServerName[] multiRackCaseWithRestrictions(Map<ServerName,Set<RegionInfo>> serverToPrimaries,
 Map<RegionInfo,ServerName[]> secondaryAndTertiaryMap,
 String primaryRack,
 ServerName primaryRS,
 RegionInfo regionInfo)
                                            throws IOException

Throws:

IOException

singleRackCase

private ServerName[] singleRackCase(RegionInfo regionInfo,
 ServerName primaryRS,
 String primaryRack)
                             throws IOException

Throws:

IOException

multiRackCase

private ServerName[] multiRackCase(ServerName primaryRS,
 String primaryRack)
                            throws IOException

Place secondary and tertiary nodes in a multi rack case. If there are only two racks, then we try the place the secondary and tertiary on different rack than primary. But if the other rack has only one region server, then we place primary and tertiary on one rack and secondary on another. The aim is two distribute the three favored nodes on >= 2 racks. TODO: see how we can use generateMissingFavoredNodeMultiRack API here

Parameters:

primaryRS - The primary favored node.

primaryRack - The rack of the primary favored node.

Returns:

Array containing secondary and tertiary favored nodes.

Throws:

IOException - Signals that an I/O exception has occurred.

canPlaceFavoredNodes

public boolean canPlaceFavoredNodes()

getTotalNumberOfRacks

private int getTotalNumberOfRacks()

getServersFromRack

private List<ServerName> getServersFromRack(String rack)

getOneRandomServer

protected ServerName getOneRandomServer(String rack,
 Set<ServerName> skipServerSet)

Gets a random server from the specified rack and skips anything specified.

Parameters:

rack - rack from a server is needed

skipServerSet - the server shouldn't belong to this set

getOneRandomServer

private ServerName getOneRandomServer(String rack)
                               throws IOException

Throws:

IOException

getOneRandomRack

String getOneRandomRack(Set<String> skipRackSet)
                 throws IOException

Throws:

IOException

getFavoredNodesAsString

public static String getFavoredNodesAsString(List<ServerName> nodes)

generateMissingFavoredNode

public ServerName generateMissingFavoredNode(List<ServerName> favoredNodes)
                                      throws IOException

Throws:

IOException

generateMissingFavoredNode

public ServerName generateMissingFavoredNode(List<ServerName> favoredNodes,
 List<ServerName> excludeNodes)
                                      throws IOException

Throws:

IOException

generateMissingFavoredNodeSingleRack

private ServerName generateMissingFavoredNodeSingleRack(List<ServerName> favoredNodes,
 List<ServerName> excludeNodes)
                                                 throws IOException

Throws:

IOException

generateMissingFavoredNodeMultiRack

private ServerName generateMissingFavoredNodeMultiRack(List<ServerName> favoredNodes)
                                                throws IOException

Throws:

IOException

generateMissingFavoredNodeMultiRack

private ServerName generateMissingFavoredNodeMultiRack(List<ServerName> favoredNodes,
 List<ServerName> excludeNodes)
                                                throws IOException

Throws:

IOException

generateFavoredNodes

public List<ServerName> generateFavoredNodes(RegionInfo hri)
                                      throws IOException

Throws:

IOException

generateFavoredNodesRoundRobin

public Map<RegionInfo,List<ServerName>> generateFavoredNodesRoundRobin(Map<ServerName,List<RegionInfo>> assignmentMap,
 List<RegionInfo> regions)
                                                                throws IOException

Throws:

IOException

generateFavoredNodes

private Map<RegionInfo,List<ServerName>> generateFavoredNodes(Map<RegionInfo,ServerName> primaryRSMap)

getRackOfServer

private String getRackOfServer(ServerName sn)