public class UpgradeIndexMergePolicy extends MergePolicyWrapper
MergePolicy
is used for upgrading all existing segments of
an index when calling IndexWriter.forceMerge(int)
.
All other methods delegate to the base MergePolicy
given to the constructor.
This allows for an as-cheap-as possible upgrade of an older index by only upgrading segments that
are created by previous Lucene versions. forceMerge does no longer really merge;
it is just used to "forceMerge" older segment versions away.
In general one would use IndexUpgrader
, but for a fully customizeable upgrade,
you can use this like any other MergePolicy
and call IndexWriter.forceMerge(int)
:
IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_XX, new KeywordAnalyzer()); iwc.setMergePolicy(new UpgradeIndexMergePolicy(iwc.getMergePolicy())); IndexWriter w = new IndexWriter(dir, iwc); w.forceMerge(1); w.close();
Warning: This merge policy may reorder documents if the index was partially
upgraded before calling forceMerge (e.g., documents were added). If your application relies
on "monotonicity" of doc IDs (which means that the order in which the documents
were added to the index is preserved), do a forceMerge(1) instead. Please note, the
delegate MergePolicy
may also reorder documents.
IndexUpgrader
MergePolicy.MergeAbortedException, MergePolicy.MergeException, MergePolicy.MergeSpecification, MergePolicy.OneMerge, MergePolicy.OneMergeProgress
in
DEFAULT_MAX_CFS_SEGMENT_SIZE, DEFAULT_NO_CFS_RATIO, maxCFSSegmentSize, noCFSRatio
Constructor and Description |
---|
UpgradeIndexMergePolicy(MergePolicy in)
Wrap the given
MergePolicy and intercept forceMerge requests to
only upgrade segments written with previous Lucene versions. |
Modifier and Type | Method and Description |
---|---|
MergePolicy.MergeSpecification |
findForcedMerges(SegmentInfos segmentInfos,
int maxSegmentCount,
Map<SegmentCommitInfo,Boolean> segmentsToMerge,
IndexWriter writer)
Determine what set of merge operations is necessary in
order to merge to
<= the specified segment count. |
MergePolicy.MergeSpecification |
findMerges(MergeTrigger mergeTrigger,
SegmentInfos segmentInfos,
IndexWriter writer)
Determine what set of merge operations are now necessary on the index.
|
protected boolean |
shouldUpgradeSegment(SegmentCommitInfo si)
Returns if the given segment should be upgraded.
|
findForcedDeletesMerges, getNoCFSRatio, setMaxCFSSegmentSizeMB, setNoCFSRatio, size, toString, useCompoundFile
getMaxCFSSegmentSizeMB, isMerged
public UpgradeIndexMergePolicy(MergePolicy in)
MergePolicy
and intercept forceMerge requests to
only upgrade segments written with previous Lucene versions.protected boolean shouldUpgradeSegment(SegmentCommitInfo si)
!Version.LATEST.equals(si.getVersion())
,
so all segments created with a different version number than this Lucene version will
get upgraded.public MergePolicy.MergeSpecification findMerges(MergeTrigger mergeTrigger, SegmentInfos segmentInfos, IndexWriter writer) throws IOException
MergePolicy
IndexWriter
calls this whenever there is a change to the segments.
This call is always synchronized on the IndexWriter
instance so
only one thread at a time will call this method.findMerges
in class MergePolicyWrapper
mergeTrigger
- the event that triggered the mergesegmentInfos
- the total set of segments in the indexwriter
- the IndexWriter to find the merges onIOException
public MergePolicy.MergeSpecification findForcedMerges(SegmentInfos segmentInfos, int maxSegmentCount, Map<SegmentCommitInfo,Boolean> segmentsToMerge, IndexWriter writer) throws IOException
MergePolicy
<=
the specified segment count. IndexWriter
calls this when its
IndexWriter.forceMerge(int)
method is called. This call is always
synchronized on the IndexWriter
instance so only one thread at a
time will call this method.findForcedMerges
in class MergePolicyWrapper
segmentInfos
- the total set of segments in the indexmaxSegmentCount
- requested maximum number of segments in the index (currently this
is always 1)segmentsToMerge
- contains the specific SegmentInfo instances that must be merged
away. This may be a subset of all
SegmentInfos. If the value is True for a
given SegmentInfo, that means this segment was
an original segment present in the
to-be-merged index; else, it was a segment
produced by a cascaded merge.writer
- the IndexWriter to find the merges onIOException
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