Package org.apache.hadoop.hbase.master.janitor

Class MetaFixer

java.lang.Object

org.apache.hadoop.hbase.master.janitor.MetaFixer

@Private
public class MetaFixer
extends Object

Server-side fixing of bad or inconsistent state in hbase:meta. Distinct from MetaTableAccessor because MetaTableAccessor is about low-level manipulations driven by the Master. This class MetaFixer is employed by the Master and it 'knows' about holes and orphans and encapsulates their fixing on behalf of the Master.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	MetaFixer.Either<L,R>	A union over MetaFixer.Either and MetaFixer.Either.

Field Summary

Fields

Modifier and Type	Field	Description
private static final org.slf4j.Logger	LOG
private final MasterServices	masterServices
private static final int	MAX_MERGE_COUNT_DEFAULT
private static final String	MAX_MERGE_COUNT_KEY
private final int	maxMergeCount	Maximum for many regions to merge at a time.

Constructor Summary

Constructors

Constructor	Description
MetaFixer(MasterServices masterServices)

Method Summary

Modifier and Type	Method	Description
private static RegionInfo	buildRegionInfo(TableName tn, byte[] start, byte[] end)
(package private) static List<SortedSet<RegionInfo>>	calculateMerges(int maxMergeCount, List<Pair<RegionInfo,RegionInfo>> overlaps)	Run through overlaps and return a list of merges to run.
private static void	calculateTableMerges(int maxMergeCount, List<SortedSet<RegionInfo>> merges, Collection<Pair<RegionInfo,RegionInfo>> overlaps)
private static List<RegionInfo>	createMetaEntries(MasterServices masterServices, List<RegionInfo> newRegionInfos)	Create entries in the hbase:meta for each provided RegionInfo.
private static List<RegionInfo>	createRegionInfosForHoles(List<Pair<RegionInfo,RegionInfo>> holes)	Create a new RegionInfo corresponding to each provided "hole" pair.
void	fix()
(package private) void	fixHoles(CatalogJanitorReport report)	If hole, it papers it over by adding a region in the filesystem and to hbase:meta.
(package private) List<Long>	fixOverlaps(CatalogJanitorReport report)	Fix overlaps noted in CJ consistency report.
private static Optional<RegionInfo>	getHoleCover(Pair<RegionInfo,RegionInfo> hole)
(package private) static RegionInfo	getRegionInfoWithLargestEndKey(RegionInfo a, RegionInfo b)
(package private) static boolean	isOverlap(RegionInfo ri, Pair<RegionInfo,RegionInfo> pair)

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

MAX_MERGE_COUNT_KEY

private static final String MAX_MERGE_COUNT_KEY

See Also:

• Constant Field Values

MAX_MERGE_COUNT_DEFAULT

private static final int MAX_MERGE_COUNT_DEFAULT

See Also:

• Constant Field Values

masterServices

private final MasterServices masterServices

maxMergeCount

private final int maxMergeCount

Maximum for many regions to merge at a time.

Constructor Details

MetaFixer

public MetaFixer(MasterServices masterServices)

Method Details

fix

public void fix()
         throws IOException

Throws:

IOException

fixHoles

void fixHoles(CatalogJanitorReport report)

If hole, it papers it over by adding a region in the filesystem and to hbase:meta. Does not assign.

createRegionInfosForHoles

private static List<RegionInfo> createRegionInfosForHoles(List<Pair<RegionInfo,RegionInfo>> holes)

Create a new RegionInfo corresponding to each provided "hole" pair.

getHoleCover

private static Optional<RegionInfo> getHoleCover(Pair<RegionInfo,RegionInfo> hole)

Returns:

Attempts to calculate a new RegionInfo that covers the region range described in hole.

buildRegionInfo

private static RegionInfo buildRegionInfo(TableName tn,
 byte[] start,
 byte[] end)

createMetaEntries

private static List<RegionInfo> createMetaEntries(MasterServices masterServices,
 List<RegionInfo> newRegionInfos)

Create entries in the hbase:meta for each provided RegionInfo. Best effort.

Parameters:

masterServices - used to connect to hbase:meta

newRegionInfos - the new RegionInfo entries to add to the filesystem

Returns:

a list of RegionInfo entries for which hbase:meta entries were successfully created

fixOverlaps

List<Long> fixOverlaps(CatalogJanitorReport report)
                throws IOException

Fix overlaps noted in CJ consistency report.

Throws:

IOException

calculateMerges

static List<SortedSet<RegionInfo>> calculateMerges(int maxMergeCount,
 List<Pair<RegionInfo,RegionInfo>> overlaps)

Run through overlaps and return a list of merges to run. Presumes overlaps are ordered (which they are coming out of the CatalogJanitor consistency report).

Parameters:

maxMergeCount - Maximum regions to merge at a time (avoid merging 100k regions in one go!)

calculateTableMerges

private static void calculateTableMerges(int maxMergeCount,
 List<SortedSet<RegionInfo>> merges,
 Collection<Pair<RegionInfo,RegionInfo>> overlaps)

getRegionInfoWithLargestEndKey

static RegionInfo getRegionInfoWithLargestEndKey(RegionInfo a,
 RegionInfo b)

Returns:

Either a or b, whichever has the endkey that is furthest along in the Table.

isOverlap

static boolean isOverlap(RegionInfo ri,
 Pair<RegionInfo,RegionInfo> pair)

Returns:

True if an overlap found between passed in ri and the pair. Does NOT check the pairs themselves overlap.