org.apache.hadoop.hbase.client

Class RegionReplicaUtil

java.lang.Object

org.apache.hadoop.hbase.client.RegionReplicaUtil

Direct Known Subclasses:

ServerRegionReplicaUtil

@InterfaceAudience.Private
public class RegionReplicaUtil
extends Object

Utility methods which contain the logic for regions and replicas.

Field Summary

Fields

Modifier and Type	Field and Description
protected static boolean	DEFAULT_REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH
(package private) static int	DEFAULT_REPLICA_ID The default replicaId for the region
static String	REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY Whether or not the secondary region will wait for observing a flush / region open event from the primary region via async wal replication before enabling read requests.

Constructor Summary

Constructors

Constructor and Description
RegionReplicaUtil()

Method Summary

Modifier and Type	Method and Description
static List<RegionInfo>	addReplicas(List<RegionInfo> regions, int oldReplicaCount, int newReplicaCount) Create any replicas for the regions (the default replicas that was already created is passed to the method)
private static int	compareRegionInfosWithoutReplicaId(RegionInfo regionInfoA, RegionInfo regionInfoB)
static RegionInfo	getRegionInfoForDefaultReplica(RegionInfo regionInfo) Returns the RegionInfo for the default replicaId (0).
static RegionInfo	getRegionInfoForReplica(RegionInfo regionInfo, int replicaId) Returns the RegionInfo for the given replicaId.
static boolean	isDefaultReplica(int replicaId)
static boolean	isDefaultReplica(RegionInfo hri)
static boolean	isReplicasForSameRegion(RegionInfo regionInfoA, RegionInfo regionInfoB)
static void	removeNonDefaultRegions(Collection<RegionInfo> regions) Removes the non-default replicas from the passed regions collection

Methods inherited from class java.lang.Object

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

Field Detail

REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY

public static final String REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH_CONF_KEY

Whether or not the secondary region will wait for observing a flush / region open event from the primary region via async wal replication before enabling read requests. Since replayed edits from async wal replication from primary is not persisted in WAL, the memstore of the secondary region might be non-empty at the time of close or crash. For ensuring seqId's not "going back in time" in the secondary region replica, this should be enabled. However, in some cases the above semantics might be ok for some application classes. See HBASE-11580 for more context.

See Also:

Constant Field Values

DEFAULT_REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH

protected static final boolean DEFAULT_REGION_REPLICA_WAIT_FOR_PRIMARY_FLUSH

See Also:

Constant Field Values

DEFAULT_REPLICA_ID

static final int DEFAULT_REPLICA_ID

The default replicaId for the region

See Also:

Constant Field Values

Constructor Detail

RegionReplicaUtil

public RegionReplicaUtil()

Method Detail

getRegionInfoForReplica

public static RegionInfo getRegionInfoForReplica(RegionInfo regionInfo,
                                                 int replicaId)

Returns the RegionInfo for the given replicaId. RegionInfo's correspond to a range of a table, but more than one "instance" of the same range can be deployed which are differentiated by the replicaId.

Parameters:

regionInfo -

replicaId - the replicaId to use

Returns:

an RegionInfo object corresponding to the same range (table, start and end key), but for the given replicaId.

getRegionInfoForDefaultReplica

public static RegionInfo getRegionInfoForDefaultReplica(RegionInfo regionInfo)

Returns the RegionInfo for the default replicaId (0). RegionInfo's correspond to a range of a table, but more than one "instance" of the same range can be deployed which are differentiated by the replicaId.

Returns:

an RegionInfo object corresponding to the same range (table, start and end key), but for the default replicaId.

isDefaultReplica

public static boolean isDefaultReplica(int replicaId)

Returns:

true if this replicaId corresponds to default replica for the region

isDefaultReplica

public static boolean isDefaultReplica(RegionInfo hri)

Returns:

true if this region is a default replica for the region

removeNonDefaultRegions

public static void removeNonDefaultRegions(Collection<RegionInfo> regions)

Removes the non-default replicas from the passed regions collection

Parameters:

regions -

isReplicasForSameRegion

public static boolean isReplicasForSameRegion(RegionInfo regionInfoA,
                                              RegionInfo regionInfoB)

compareRegionInfosWithoutReplicaId

private static int compareRegionInfosWithoutReplicaId(RegionInfo regionInfoA,
                                                      RegionInfo regionInfoB)

addReplicas

public static List<RegionInfo> addReplicas(List<RegionInfo> regions,
                                           int oldReplicaCount,
                                           int newReplicaCount)

Create any replicas for the regions (the default replicas that was already created is passed to the method)

Parameters:

regions - existing regions

oldReplicaCount - existing replica count

newReplicaCount - updated replica count due to modify table

Returns:

the combined list of default and non-default replicas