Package org.apache.hadoop.hbase

Class AsyncMetaTableAccessor

java.lang.Object

org.apache.hadoop.hbase.AsyncMetaTableAccessor

@Private
public class AsyncMetaTableAccessor
extends Object

The asynchronous meta table accessor. Used to read/write region and assignment information store in hbase:meta.

Since:

2.0.0

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	AsyncMetaTableAccessor.MetaTableScanResultConsumer

Field Summary

Fields

Modifier and Type	Field	Description
private static final org.slf4j.Logger	LOG
private static final char	META_REPLICA_ID_DELIMITER	The delimiter for meta columns for replicaIds > 0
private static final Pattern	SERVER_COLUMN_PATTERN	A regex for parsing server columns from meta.

Constructor Summary

Constructors

Constructor	Description
AsyncMetaTableAccessor()

Method Summary

Modifier and Type	Method	Description
private static byte[]	getCatalogFamily()	Returns the column family used for meta columns.
private static Optional<RegionInfo>	getHRegionInfo(Result r, byte[] qualifier)	Returns the RegionInfo object from the column HConstants.CATALOG_FAMILY and qualifier of the catalog table result.
private static Scan	getMetaScan(AsyncTable<?> metaTable, int rowUpperLimit)
private static byte[]	getRegionInfoColumn()	Returns the column qualifier for serialized region info
static CompletableFuture<Optional<HRegionLocation>>	getRegionLocation(AsyncTable<?> metaTable, byte[] regionName)	Returns the HRegionLocation from meta for the given region
private static HRegionLocation	getRegionLocation(Result r, RegionInfo regionInfo, int replicaId)	Returns the HRegionLocation parsed from the given meta row Result for the given regionInfo and replicaId.
private static Optional<RegionLocations>	getRegionLocations(Result r)	Returns an HRegionLocationList extracted from the result.
static CompletableFuture<Optional<HRegionLocation>>	getRegionLocationWithEncodedName(AsyncTable<?> metaTable, byte[] encodedRegionName)	Returns the HRegionLocation from meta for the given encoded region name
private static byte[]	getSeqNumColumn(int replicaId)	Returns the column qualifier for seqNum column for replicaId
private static long	getSeqNumDuringOpen(Result r, int replicaId)	The latest seqnum that the server writing to meta observed when opening the region.
private static byte[]	getServerColumn(int replicaId)	Returns the column qualifier for server column for replicaId
private static Optional<ServerName>	getServerName(Result r, int replicaId)	Returns a ServerName from catalog table Result.
private static byte[]	getStartCodeColumn(int replicaId)	Returns the column qualifier for server start code column for replicaId
private static byte[]	getStateColumn()	Returns the column qualifier for serialized table state
private static byte[]	getTableFamily()	Returns the column family used for table columns.
static CompletableFuture<List<HRegionLocation>>	getTableHRegionLocations(AsyncTable<AdvancedScanResultConsumer> metaTable, TableName tableName)	Used to get all region locations for the specific table
private static CompletableFuture<List<Pair<RegionInfo,ServerName>>>	getTableRegionsAndLocations(AsyncTable<AdvancedScanResultConsumer> metaTable, TableName tableName, boolean excludeOfflinedSplitParents)	Used to get table regions' info and server.
private static byte[]	getTableStartRowForMeta(TableName tableName, MetaTableAccessor.QueryType type)
static CompletableFuture<Optional<TableState>>	getTableState(AsyncTable<?> metaTable, TableName tableName)
private static Optional<TableState>	getTableState(Result r)
private static byte[]	getTableStopRowForMeta(TableName tableName, MetaTableAccessor.QueryType type)
private static int	parseReplicaIdFromServerColumn(byte[] serverColumn)	Parses the replicaId from the server column qualifier.
private static CompletableFuture<Void>	scanMeta(AsyncTable<AdvancedScanResultConsumer> metaTable, byte[] startRow, byte[] stopRow, MetaTableAccessor.QueryType type, int maxRows, MetaTableAccessor.Visitor visitor)	Performs a scan of META table for given table.
private static CompletableFuture<Void>	scanMeta(AsyncTable<AdvancedScanResultConsumer> metaTable, TableName tableName, MetaTableAccessor.QueryType type, MetaTableAccessor.Visitor visitor)	Performs a scan of META table for given table.
static CompletableFuture<Boolean>	tableExists(AsyncTable<?> metaTable, TableName tableName)

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

META_REPLICA_ID_DELIMITER

private static final char META_REPLICA_ID_DELIMITER

The delimiter for meta columns for replicaIds > 0

See Also:

• Constant Field Values

SERVER_COLUMN_PATTERN

private static final Pattern SERVER_COLUMN_PATTERN

A regex for parsing server columns from meta. See above javadoc for meta layout

Constructor Details

AsyncMetaTableAccessor

public AsyncMetaTableAccessor()

Method Details

tableExists

public static CompletableFuture<Boolean> tableExists(AsyncTable<?> metaTable,
 TableName tableName)

getTableState

public static CompletableFuture<Optional<TableState>> getTableState(AsyncTable<?> metaTable,
 TableName tableName)

getRegionLocation

public static CompletableFuture<Optional<HRegionLocation>> getRegionLocation(AsyncTable<?> metaTable,
 byte[] regionName)

Returns the HRegionLocation from meta for the given region

getRegionLocationWithEncodedName

public static CompletableFuture<Optional<HRegionLocation>> getRegionLocationWithEncodedName(AsyncTable<?> metaTable,
 byte[] encodedRegionName)

Returns the HRegionLocation from meta for the given encoded region name

getTableState

private static Optional<TableState> getTableState(Result r)
                                           throws IOException

Throws:

IOException

getTableHRegionLocations

public static CompletableFuture<List<HRegionLocation>> getTableHRegionLocations(AsyncTable<AdvancedScanResultConsumer> metaTable,
 TableName tableName)

Used to get all region locations for the specific table

Parameters:

metaTable - scanner over meta table

tableName - table we're looking for, can be null for getting all regions

Returns:

the list of region locations. The return value will be wrapped by a CompletableFuture.

getTableRegionsAndLocations

private static CompletableFuture<List<Pair<RegionInfo,ServerName>>> getTableRegionsAndLocations(AsyncTable<AdvancedScanResultConsumer> metaTable,
 TableName tableName,
 boolean excludeOfflinedSplitParents)

Used to get table regions' info and server.

Parameters:

metaTable - scanner over meta table

tableName - table we're looking for, can be null for getting all regions

excludeOfflinedSplitParents - don't return split parents

Returns:

the list of regioninfos and server. The return value will be wrapped by a CompletableFuture.

scanMeta

private static CompletableFuture<Void> scanMeta(AsyncTable<AdvancedScanResultConsumer> metaTable,
 TableName tableName,
 MetaTableAccessor.QueryType type,
 MetaTableAccessor.Visitor visitor)

Performs a scan of META table for given table.

Parameters:

metaTable - scanner over meta table

tableName - table within we scan

type - scanned part of meta

visitor - Visitor invoked against each row

scanMeta

private static CompletableFuture<Void> scanMeta(AsyncTable<AdvancedScanResultConsumer> metaTable,
 byte[] startRow,
 byte[] stopRow,
 MetaTableAccessor.QueryType type,
 int maxRows,
 MetaTableAccessor.Visitor visitor)

Performs a scan of META table for given table.

Parameters:

metaTable - scanner over meta table

startRow - Where to start the scan

stopRow - Where to stop the scan

type - scanned part of meta

maxRows - maximum rows to return

visitor - Visitor invoked against each row

getMetaScan

private static Scan getMetaScan(AsyncTable<?> metaTable,
 int rowUpperLimit)

getRegionLocations

private static Optional<RegionLocations> getRegionLocations(Result r)

Returns an HRegionLocationList extracted from the result.

Returns:

an HRegionLocationList containing all locations for the region range or null if we can't deserialize the result.

getRegionLocation

private static HRegionLocation getRegionLocation(Result r,
 RegionInfo regionInfo,
 int replicaId)

Returns the HRegionLocation parsed from the given meta row Result for the given regionInfo and replicaId. The regionInfo can be the default region info for the replica.

Parameters:

r - the meta row result

regionInfo - RegionInfo for default replica

replicaId - the replicaId for the HRegionLocation

Returns:

HRegionLocation parsed from the given meta row Result for the given replicaId

getServerName

private static Optional<ServerName> getServerName(Result r,
 int replicaId)

Returns a ServerName from catalog table Result.

Parameters:

r - Result to pull from

Returns:

A ServerName instance.

getSeqNumDuringOpen

private static long getSeqNumDuringOpen(Result r,
 int replicaId)

The latest seqnum that the server writing to meta observed when opening the region. E.g. the seqNum when the result of getServerName(Result, int) was written.

Parameters:

r - Result to pull the seqNum from

Returns:

SeqNum, or HConstants.NO_SEQNUM if there's no value written.

getTableStartRowForMeta

private static byte[] getTableStartRowForMeta(TableName tableName,
 MetaTableAccessor.QueryType type)

Parameters:

tableName - table we're working with

Returns:

start row for scanning META according to query type

getTableStopRowForMeta

private static byte[] getTableStopRowForMeta(TableName tableName,
 MetaTableAccessor.QueryType type)

Parameters:

tableName - table we're working with

Returns:

stop row for scanning META according to query type

getHRegionInfo

private static Optional<RegionInfo> getHRegionInfo(Result r,
 byte[] qualifier)

Returns the RegionInfo object from the column HConstants.CATALOG_FAMILY and qualifier of the catalog table result.

Parameters:

r - a Result object from the catalog table scan

qualifier - Column family qualifier

Returns:

An RegionInfo instance.

getCatalogFamily

private static byte[] getCatalogFamily()

Returns the column family used for meta columns.

Returns:

HConstants.CATALOG_FAMILY.

getTableFamily

private static byte[] getTableFamily()

Returns the column family used for table columns.

Returns:

HConstants.TABLE_FAMILY.

getRegionInfoColumn

private static byte[] getRegionInfoColumn()

Returns the column qualifier for serialized region info

Returns:

HConstants.REGIONINFO_QUALIFIER

getStateColumn

private static byte[] getStateColumn()

Returns the column qualifier for serialized table state

Returns:

HConstants.TABLE_STATE_QUALIFIER

getServerColumn

private static byte[] getServerColumn(int replicaId)

Returns the column qualifier for server column for replicaId

Parameters:

replicaId - the replicaId of the region

Returns:

a byte[] for server column qualifier

getStartCodeColumn

private static byte[] getStartCodeColumn(int replicaId)

Returns the column qualifier for server start code column for replicaId

Parameters:

replicaId - the replicaId of the region

Returns:

a byte[] for server start code column qualifier

getSeqNumColumn

private static byte[] getSeqNumColumn(int replicaId)

Returns the column qualifier for seqNum column for replicaId

Parameters:

replicaId - the replicaId of the region

Returns:

a byte[] for seqNum column qualifier

parseReplicaIdFromServerColumn

private static int parseReplicaIdFromServerColumn(byte[] serverColumn)

Parses the replicaId from the server column qualifier. See top of the class javadoc for the actual meta layout

Parameters:

serverColumn - the column qualifier

Returns:

an int for the replicaId