FavoredNodeAssignmentHelper (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.master.balancer.FavoredNodeAssignmentHelper

```
@InterfaceAudience.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(HRegionInfo, List)).

Field Summary

Fields
Modifier and Type	Field and Description
`static short`	`FAVORED_NODES_NUM`
`static byte[]`	`FAVOREDNODES_QUALIFIER`
`private static org.apache.commons.logging.Log`	`LOG`
`private RackManager`	`rackManager`
`private Map<String,List<ServerName>>`	`rackToRegionServerMap`
`private Random`	`random`
`private Map<ServerName,String>`	`regionServerToRackMap`
`private List<ServerName>`	`servers`
`private List<String>`	`uniqueRackList`

Constructor Summary

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

Method Summary

Methods
Modifier and Type	Method and Description
`(package private) boolean`	`canPlaceFavoredNodes()`
`static byte[]`	`getFavoredNodes(List<ServerName> serverAddrList)`
`static String`	`getFavoredNodesAsString(List<ServerName> nodes)`
`static ServerName[]`	`getFavoredNodesList(byte[] favoredNodes)`
`private String`	`getOneRandomRack(Set<String> skipRackSet)`
`private ServerName`	`getOneRandomServer(String rack)`
`private ServerName`	`getOneRandomServer(String rack, Set<ServerName> skipServerSet)`
`private List<ServerName>`	`getServersFromRack(String rack)`
`private int`	`getTotalNumberOfRacks()`
`void`	`initialize()`
`(package private) static Put`	`makePutFromRegionInfo(HRegionInfo regionInfo, List<ServerName> favoredNodeList)` Generates and returns a Put containing the region info for the catalog table and the servers
`private Map<ServerName,Set<HRegionInfo>>`	`mapRSToPrimaries(Map<HRegionInfo,ServerName> primaryRSMap)`
`private ServerName[]`	`multiRackCase(HRegionInfo regionInfo, ServerName primaryRS, String primaryRack)`
`private ServerName[]`	`multiRackCaseWithRestrictions(Map<ServerName,Set<HRegionInfo>> serverToPrimaries, Map<HRegionInfo,ServerName[]> secondaryAndTertiaryMap, String primaryRack, ServerName primaryRS, HRegionInfo regionInfo)`
`(package private) void`	`placePrimaryRSAsRoundRobin(Map<ServerName,List<HRegionInfo>> assignmentMap, Map<HRegionInfo,ServerName> primaryRSMap, List<HRegionInfo> regions)`
`(package private) Map<HRegionInfo,ServerName[]>`	`placeSecondaryAndTertiaryRS(Map<HRegionInfo,ServerName> primaryRSMap)`
`Map<HRegionInfo,ServerName[]>`	`placeSecondaryAndTertiaryWithRestrictions(Map<HRegionInfo,ServerName> primaryRSMap)` For regions that share the primary, avoid placing the secondary and tertiary on a same RS.
`private ServerName[]`	`singleRackCase(HRegionInfo regionInfo, ServerName primaryRS, String primaryRack)`
`static void`	`updateMetaWithFavoredNodesInfo(Map<HRegionInfo,List<ServerName>> regionToFavoredNodes, org.apache.hadoop.conf.Configuration conf)` Update meta table with favored nodes info
`static void`	`updateMetaWithFavoredNodesInfo(Map<HRegionInfo,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 Detail

LOG

private static final org.apache.commons.logging.Log LOG

rackManager
```
private RackManager rackManager
```

rackToRegionServerMap

private Map<String,List<ServerName>> rackToRegionServerMap

uniqueRackList
```
private List<String> uniqueRackList
```

regionServerToRackMap

private Map<ServerName,String> regionServerToRackMap

random
```
private Random random
```

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

Constructor Detail

FavoredNodeAssignmentHelper

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

FavoredNodeAssignmentHelper

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

Method Detail

updateMetaWithFavoredNodesInfo

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

Update meta table with favored nodes info

Parameters:: regionToFavoredNodes - map of HRegionInfo's to their favored nodes; connection - connection to be used
Throws:: IOException

updateMetaWithFavoredNodesInfo

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

Update meta table with favored nodes info

Parameters:: regionToFavoredNodes -; conf -
Throws:: IOException

makePutFromRegionInfo

static Put makePutFromRegionInfo(HRegionInfo regionInfo,
                        List<ServerName> favoredNodeList)
                          throws IOException

Generates and returns a Put containing the region info for the catalog table and the servers

Parameters:: regionInfo -; favoredNodeList -
Returns:: Put object
Throws:: IOException

getFavoredNodesList
```
public static ServerName[] getFavoredNodesList(byte[] favoredNodes)
                                        throws com.google.protobuf.InvalidProtocolBufferException
```
Parameters:
favoredNodes - The PB'ed bytes of favored nodes

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

Throws:

com.google.protobuf.InvalidProtocolBufferException

getFavoredNodes
```
public static byte[] getFavoredNodes(List<ServerName> serverAddrList)
```
Parameters:
serverAddrList -

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

placePrimaryRSAsRoundRobin

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

placeSecondaryAndTertiaryRS

Map<HRegionInfo,ServerName[]> placeSecondaryAndTertiaryRS(Map<HRegionInfo,ServerName> primaryRSMap)

mapRSToPrimaries

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

placeSecondaryAndTertiaryWithRestrictions
```
public Map<HRegionInfo,ServerName[]> placeSecondaryAndTertiaryWithRestrictions(Map<HRegionInfo,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

Parameters:
primaryRSMap -

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

multiRackCaseWithRestrictions

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

Throws:: IOException

singleRackCase

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

Throws:: IOException

multiRackCase

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

Throws:: IOException

canPlaceFavoredNodes
```
boolean canPlaceFavoredNodes()
```

initialize
```
public void initialize()
```

getTotalNumberOfRacks
```
private int getTotalNumberOfRacks()
```

getServersFromRack

private List<ServerName> getServersFromRack(String rack)

getOneRandomServer

private ServerName getOneRandomServer(String rack,
                            Set<ServerName> skipServerSet)
                               throws IOException

Throws:: IOException

getOneRandomServer

private ServerName getOneRandomServer(String rack)
                               throws IOException

Throws:: IOException

getOneRandomRack

private String getOneRandomRack(Set<String> skipRackSet)
                         throws IOException

Throws:: IOException

getFavoredNodesAsString

public static String getFavoredNodesAsString(List<ServerName> nodes)

Class FavoredNodeAssignmentHelper

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

LOG

rackManager

rackToRegionServerMap

uniqueRackList

regionServerToRackMap

random

servers

FAVOREDNODES_QUALIFIER

FAVORED_NODES_NUM

Constructor Detail

FavoredNodeAssignmentHelper

FavoredNodeAssignmentHelper

Method Detail

updateMetaWithFavoredNodesInfo

updateMetaWithFavoredNodesInfo

makePutFromRegionInfo

getFavoredNodesList

getFavoredNodes

placePrimaryRSAsRoundRobin

placeSecondaryAndTertiaryRS

mapRSToPrimaries

placeSecondaryAndTertiaryWithRestrictions

multiRackCaseWithRestrictions

singleRackCase

multiRackCase

canPlaceFavoredNodes

initialize

getTotalNumberOfRacks

getServersFromRack

getOneRandomServer

getOneRandomServer

getOneRandomRack

getFavoredNodesAsString