Package org.apache.lucene.index

Class LiveIndexWriterConfig

java.lang.Object
org.apache.lucene.index.LiveIndexWriterConfig
Direct Known Subclasses:
IndexWriterConfig
public class LiveIndexWriterConfig extends Object
Holds all the configuration used by IndexWriter with few setters for settings that can be changed on an IndexWriter instance "live".
Since:
4.0

  • Field Details

    • delPolicy

      protected volatile IndexDeletionPolicy delPolicy
      IndexDeletionPolicy controlling when commit points are deleted.

    • commit

      protected volatile IndexCommit commit
      IndexCommit that IndexWriter is opened on.

    • openMode

      protected volatile IndexWriterConfig.OpenMode openMode
      IndexWriterConfig.OpenMode that IndexWriter is opened with.

    • similarity

      protected volatile Similarity similarity
      Similarity to use when encoding norms.

    • mergeScheduler

      protected volatile MergeScheduler mergeScheduler
      MergeScheduler to use for running merges.

    • writeLockTimeout

      protected volatile long writeLockTimeout
      Timeout when trying to obtain the write lock on init.

    • indexingChain

      protected volatile org.apache.lucene.index.DocumentsWriterPerThread.IndexingChain indexingChain
      DocumentsWriterPerThread.IndexingChain that determines how documents are indexed.

    • codec

      protected volatile Codec codec
      Codec used to write new segments.

    • infoStream

      protected volatile InfoStream infoStream
      InfoStream for debugging messages.

    • mergePolicy

      protected volatile MergePolicy mergePolicy
      MergePolicy for selecting merges.

    • indexerThreadPool

      protected volatile org.apache.lucene.index.DocumentsWriterPerThreadPool indexerThreadPool
      DocumentsWriterPerThreadPool to control how threads are allocated to DocumentsWriterPerThread.

    • readerPooling

      protected volatile boolean readerPooling
      True if readers should be pooled.

    • flushPolicy

      protected volatile org.apache.lucene.index.FlushPolicy flushPolicy
      FlushPolicy to control when segments are flushed.

    • perThreadHardLimitMB

      protected volatile int perThreadHardLimitMB
      Sets the hard upper bound on RAM usage for a single segment, after which the segment is forced to flush.

    • matchVersion

      protected final Version matchVersion
      Version that IndexWriter should emulate.

    • useCompoundFile

      protected volatile boolean useCompoundFile
      True if segment flushes should use compound file format

  • Method Details

    • getAnalyzer

      public Analyzer getAnalyzer()
      Returns the default analyzer to use for indexing documents.

    • setTermIndexInterval

      public LiveIndexWriterConfig setTermIndexInterval(int interval)
      Expert: set the interval between indexed terms. Large values cause less memory to be used by IndexReader, but slow random-access to terms. Small values cause more memory to be used by an IndexReader, and speed random-access to terms.

      This parameter determines the amount of computation required per query term, regardless of the number of documents that contain that term. In particular, it is the maximum number of other terms that must be scanned before a term is located and its frequency and position information may be processed. In a large index with user-entered query terms, query processing time is likely to be dominated not by term lookup but rather by the processing of frequency and positional data. In a small index or when many uncommon query terms are generated (e.g., by wildcard queries) term lookup may become a dominant cost.

      In particular, numUniqueTerms/interval terms are read into memory by an IndexReader, and, on average, interval/2 terms must be scanned for each random term access.

      Takes effect immediately, but only applies to newly flushed/merged segments.

      NOTE: This parameter does not apply to all PostingsFormat implementations, including the default one in this release. It only makes sense for term indexes that are implemented as a fixed gap between terms. For example, Lucene41PostingsFormat implements the term index instead based upon how terms share prefixes. To configure its parameters (the minimum and maximum size for a block), you would instead use Lucene41PostingsFormat(int, int). which can also be configured on a per-field basis: 

       //customize Lucene41PostingsFormat, passing minBlockSize=50, maxBlockSize=100
 final PostingsFormat tweakedPostings = new Lucene41PostingsFormat(50, 100);
 iwc.setCodec(new Lucene45Codec() {
   @Override
   public PostingsFormat getPostingsFormatForField(String field) {
     if (field.equals("fieldWithTonsOfTerms"))
       return tweakedPostings;
     else
       return super.getPostingsFormatForField(field);
   }
 });
      Note that other implementations may have their own parameters, or no parameters at all.
      See Also:

    • getTermIndexInterval

      public int getTermIndexInterval()
      Returns the interval between indexed terms.
      See Also:

    • setMaxBufferedDeleteTerms

      public LiveIndexWriterConfig setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms)
      Determines the maximum number of delete-by-term operations that will be buffered before both the buffered in-memory delete terms and queries are applied and flushed.

      Disabled by default (writer flushes by RAM usage).

      NOTE: This setting won't trigger a segment flush.

      Takes effect immediately, but only the next time a document is added, updated or deleted. Also, if you only delete-by-query, this setting has no effect, i.e. delete queries are buffered until the next segment is flushed.

      Throws:
      IllegalArgumentException - if maxBufferedDeleteTerms is enabled but smaller than 1
      See Also:

    • getMaxBufferedDeleteTerms

      public int getMaxBufferedDeleteTerms()
      Returns the number of buffered deleted terms that will trigger a flush of all buffered deletes if enabled.
      See Also:

    • setRAMBufferSizeMB

      public LiveIndexWriterConfig setRAMBufferSizeMB(double ramBufferSizeMB)
      Determines the amount of RAM that may be used for buffering added documents and deletions before they are flushed to the Directory. Generally for faster indexing performance it's best to flush by RAM usage instead of document count and use as large a RAM buffer as you can.

      When this is set, the writer will flush whenever buffered documents and deletions use this much RAM. Pass in IndexWriterConfig.DISABLE_AUTO_FLUSH to prevent triggering a flush due to RAM usage. Note that if flushing by document count is also enabled, then the flush will be triggered by whichever comes first.

      The maximum RAM limit is inherently determined by the JVMs available memory. Yet, an IndexWriter session can consume a significantly larger amount of memory than the given RAM limit since this limit is just an indicator when to flush memory resident documents to the Directory. Flushes are likely happen concurrently while other threads adding documents to the writer. For application stability the available memory in the JVM should be significantly larger than the RAM buffer used for indexing.

      NOTE: the account of RAM usage for pending deletions is only approximate. Specifically, if you delete by Query, Lucene currently has no way to measure the RAM usage of individual Queries so the accounting will under-estimate and you should compensate by either calling commit() periodically yourself, or by using setMaxBufferedDeleteTerms(int) to flush and apply buffered deletes by count instead of RAM usage (for each buffered delete Query a constant number of bytes is used to estimate RAM usage). Note that enabling setMaxBufferedDeleteTerms(int) will not trigger any segment flushes.

      NOTE: It's not guaranteed that all memory resident documents are flushed once this limit is exceeded. Depending on the configured FlushPolicy only a subset of the buffered documents are flushed and therefore only parts of the RAM buffer is released.

      The default value is IndexWriterConfig.DEFAULT_RAM_BUFFER_SIZE_MB.

      Takes effect immediately, but only the next time a document is added, updated or deleted.

      Throws:
      IllegalArgumentException - if ramBufferSize is enabled but non-positive, or it disables ramBufferSize when maxBufferedDocs is already disabled
      See Also:

    • getRAMBufferSizeMB

      public double getRAMBufferSizeMB()
      Returns the value set by setRAMBufferSizeMB(double) if enabled.

    • setMaxBufferedDocs

      public LiveIndexWriterConfig setMaxBufferedDocs(int maxBufferedDocs)
      Determines the minimal number of documents required before the buffered in-memory documents are flushed as a new Segment. Large values generally give faster indexing.

      When this is set, the writer will flush every maxBufferedDocs added documents. Pass in IndexWriterConfig.DISABLE_AUTO_FLUSH to prevent triggering a flush due to number of buffered documents. Note that if flushing by RAM usage is also enabled, then the flush will be triggered by whichever comes first.

      Disabled by default (writer flushes by RAM usage).

      Takes effect immediately, but only the next time a document is added, updated or deleted.

      Throws:
      IllegalArgumentException - if maxBufferedDocs is enabled but smaller than 2, or it disables maxBufferedDocs when ramBufferSize is already disabled
      See Also:

    • getMaxBufferedDocs

      public int getMaxBufferedDocs()
      Returns the number of buffered added documents that will trigger a flush if enabled.
      See Also:

    • setMergedSegmentWarmer

      public LiveIndexWriterConfig setMergedSegmentWarmer(IndexWriter.IndexReaderWarmer mergeSegmentWarmer)
      Set the merged segment warmer. See IndexWriter.IndexReaderWarmer.

      Takes effect on the next merge.

    • getMergedSegmentWarmer

      public IndexWriter.IndexReaderWarmer getMergedSegmentWarmer()
      Returns the current merged segment warmer. See IndexWriter.IndexReaderWarmer.

    • setReaderTermsIndexDivisor

      public LiveIndexWriterConfig setReaderTermsIndexDivisor(int divisor)
      Sets the termsIndexDivisor passed to any readers that IndexWriter opens, for example when applying deletes or creating a near-real-time reader in DirectoryReader.open(IndexWriter, boolean). If you pass -1, the terms index won't be loaded by the readers. This is only useful in advanced situations when you will only .next() through all terms; attempts to seek will hit an exception.

      Takes effect immediately, but only applies to readers opened after this call

      NOTE: divisor settings > 1 do not apply to all PostingsFormat implementations, including the default one in this release. It only makes sense for terms indexes that can efficiently re-sample terms at load time.

    • getReaderTermsIndexDivisor

      public int getReaderTermsIndexDivisor()
      Returns the termInfosIndexDivisor.
      See Also:

    • getOpenMode

      public IndexWriterConfig.OpenMode getOpenMode()
      Returns the IndexWriterConfig.OpenMode set by IndexWriterConfig.setOpenMode(OpenMode).

    • getIndexDeletionPolicy

      public IndexDeletionPolicy getIndexDeletionPolicy()
      Returns the IndexDeletionPolicy specified in IndexWriterConfig.setIndexDeletionPolicy(IndexDeletionPolicy) or the default KeepOnlyLastCommitDeletionPolicy/

    • getIndexCommit

      public IndexCommit getIndexCommit()
      Returns the IndexCommit as specified in IndexWriterConfig.setIndexCommit(IndexCommit) or the default, null which specifies to open the latest index commit point.

    • getSimilarity

      public Similarity getSimilarity()
      Expert: returns the Similarity implementation used by this IndexWriter.

    • getMergeScheduler

      public MergeScheduler getMergeScheduler()
      Returns the MergeScheduler that was set by IndexWriterConfig.setMergeScheduler(MergeScheduler).

    • getWriteLockTimeout

      public long getWriteLockTimeout()
      Returns allowed timeout when acquiring the write lock.
      See Also:

    • getCodec

      public Codec getCodec()
      Returns the current Codec.

    • getMergePolicy

      public MergePolicy getMergePolicy()
      Returns the current MergePolicy in use by this writer.
      See Also:

    • getMaxThreadStates

      public int getMaxThreadStates()
      Returns the max number of simultaneous threads that may be indexing documents at once in IndexWriter.

    • getReaderPooling

      public boolean getReaderPooling()
      Returns true if IndexWriter should pool readers even if DirectoryReader.open(IndexWriter, boolean) has not been called.

    • getRAMPerThreadHardLimitMB

      public int getRAMPerThreadHardLimitMB()
      Returns the max amount of memory each DocumentsWriterPerThread can consume until forcefully flushed.
      See Also:

    • getInfoStream

      public InfoStream getInfoStream()
      Returns InfoStream used for debugging.
      See Also:

    • setUseCompoundFile

      public LiveIndexWriterConfig setUseCompoundFile(boolean useCompoundFile)
      Sets if the IndexWriter should pack newly written segments in a compound file. Default is true.

      Use false for batch indexing with very large ram buffer settings.

      Note: To control compound file usage during segment merges see MergePolicy.setNoCFSRatio(double) and MergePolicy.setMaxCFSSegmentSizeMB(double). This setting only applies to newly created segments.

    • getUseCompoundFile

      public boolean getUseCompoundFile()
      Returns true iff the IndexWriter packs newly written segments in a compound file. Default is true.

    • toString

      public String toString()
      Overrides:
      toString in class Object