LiveIndexWriterConfig (Lucene 4.2.0 API)

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 Summary

Fields
Modifier and Type	Field and Description
`protected Codec`	`codec` `Codec` used to write new segments.
`protected IndexCommit`	`commit` `IndexCommit` that `IndexWriter` is opened on.
`protected IndexDeletionPolicy`	`delPolicy` `IndexDeletionPolicy` controlling when commit points are deleted.
`protected org.apache.lucene.index.FlushPolicy`	`flushPolicy` `FlushPolicy` to control when segments are flushed.
`protected org.apache.lucene.index.DocumentsWriterPerThreadPool`	`indexerThreadPool` `DocumentsWriterPerThreadPool` to control how threads are allocated to `DocumentsWriterPerThread`.
`protected org.apache.lucene.index.DocumentsWriterPerThread.IndexingChain`	`indexingChain` `DocumentsWriterPerThread.IndexingChain` that determines how documents are indexed.
`protected InfoStream`	`infoStream` `InfoStream` for debugging messages.
`protected Version`	`matchVersion` `Version` that `IndexWriter` should emulate.
`protected MergePolicy`	`mergePolicy` `MergePolicy` for selecting merges.
`protected MergeScheduler`	`mergeScheduler` `MergeScheduler` to use for running merges.
`protected IndexWriterConfig.OpenMode`	`openMode` `IndexWriterConfig.OpenMode` that `IndexWriter` is opened with.
`protected int`	`perThreadHardLimitMB` Sets the hard upper bound on RAM usage for a single segment, after which the segment is forced to flush.
`protected boolean`	`readerPooling` True if readers should be pooled.
`protected Similarity`	`similarity` `Similarity` to use when encoding norms.
`protected long`	`writeLockTimeout` Timeout when trying to obtain the write lock on init.

Method Summary

Methods
Modifier and Type	Method and Description
`Analyzer`	`getAnalyzer()` Returns the default analyzer to use for indexing documents.
`Codec`	`getCodec()` Returns the current `Codec`.
`IndexCommit`	`getIndexCommit()` Returns the `IndexCommit` as specified in `IndexWriterConfig.setIndexCommit(IndexCommit)` or the default, `null` which specifies to open the latest index commit point.
`IndexDeletionPolicy`	`getIndexDeletionPolicy()` Returns the `IndexDeletionPolicy` specified in `IndexWriterConfig.setIndexDeletionPolicy(IndexDeletionPolicy)` or the default `KeepOnlyLastCommitDeletionPolicy`/
`InfoStream`	`getInfoStream()` Returns `InfoStream` used for debugging.
`int`	`getMaxBufferedDeleteTerms()` Returns the number of buffered deleted terms that will trigger a flush of all buffered deletes if enabled.
`int`	`getMaxBufferedDocs()` Returns the number of buffered added documents that will trigger a flush if enabled.
`int`	`getMaxThreadStates()` Returns the max number of simultaneous threads that may be indexing documents at once in IndexWriter.
`IndexWriter.IndexReaderWarmer`	`getMergedSegmentWarmer()` Returns the current merged segment warmer.
`MergePolicy`	`getMergePolicy()` Returns the current MergePolicy in use by this writer.
`MergeScheduler`	`getMergeScheduler()` Returns the `MergeScheduler` that was set by `IndexWriterConfig.setMergeScheduler(MergeScheduler)`.
`IndexWriterConfig.OpenMode`	`getOpenMode()` Returns the `IndexWriterConfig.OpenMode` set by `IndexWriterConfig.setOpenMode(OpenMode)`.
`double`	`getRAMBufferSizeMB()` Returns the value set by `setRAMBufferSizeMB(double)` if enabled.
`int`	`getRAMPerThreadHardLimitMB()` Returns the max amount of memory each `DocumentsWriterPerThread` can consume until forcefully flushed.
`boolean`	`getReaderPooling()` Returns `true` if `IndexWriter` should pool readers even if `DirectoryReader.open(IndexWriter, boolean)` has not been called.
`int`	`getReaderTermsIndexDivisor()` Returns the `termInfosIndexDivisor`.
`Similarity`	`getSimilarity()` Expert: returns the `Similarity` implementation used by this `IndexWriter`.
`int`	`getTermIndexInterval()` Returns the interval between indexed terms.
`long`	`getWriteLockTimeout()` Returns allowed timeout when acquiring the write lock.
`LiveIndexWriterConfig`	`setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms)` Determines the minimal number of delete terms required before the buffered in-memory delete terms and queries are applied and flushed.
`LiveIndexWriterConfig`	`setMaxBufferedDocs(int maxBufferedDocs)` Determines the minimal number of documents required before the buffered in-memory documents are flushed as a new Segment.
`LiveIndexWriterConfig`	`setMergedSegmentWarmer(IndexWriter.IndexReaderWarmer mergeSegmentWarmer)` Set the merged segment warmer.
`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.
`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)`.
`LiveIndexWriterConfig`	`setTermIndexInterval(int interval)` Expert: set the interval between indexed terms.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - 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.
- Method Detail
  - 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.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 Lucene42Codec() {
   @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:
    IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL
  - getTermIndexInterval
```
public int getTermIndexInterval()
```
    Returns the interval between indexed terms.
    
    See Also:
    setTermIndexInterval(int)
  - setMaxBufferedDeleteTerms
```
public LiveIndexWriterConfig setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms)
```
    Determines the minimal number of delete terms required before 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.
    
    Throws:
    
    IllegalArgumentException - if maxBufferedDeleteTerms is enabled but smaller than 1
    See Also:
    setRAMBufferSizeMB(double)
  - getMaxBufferedDeleteTerms
```
public int getMaxBufferedDeleteTerms()
```
    Returns the number of buffered deleted terms that will trigger a flush of all buffered deletes if enabled.
    
    See Also:
    setMaxBufferedDeleteTerms(int)
  - 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:
    IndexWriterConfig.setRAMPerThreadHardLimitMB(int)
  - 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:
    setRAMBufferSizeMB(double)
  - getMaxBufferedDocs
```
public int getMaxBufferedDocs()
```
    Returns the number of buffered added documents that will trigger a flush if enabled.
    
    See Also:
    setMaxBufferedDocs(int)
  - 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:
    setReaderTermsIndexDivisor(int)
  - 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:
    IndexWriterConfig.setWriteLockTimeout(long)
  - getCodec
```
public Codec getCodec()
```
    Returns the current Codec.
  - getMergePolicy
```
public MergePolicy getMergePolicy()
```
    Returns the current MergePolicy in use by this writer.
    
    See Also:
    IndexWriterConfig.setMergePolicy(MergePolicy)
  - 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:
    IndexWriterConfig.setRAMPerThreadHardLimitMB(int)
  - getInfoStream
```
public InfoStream getInfoStream()
```
    Returns InfoStream used for debugging.
    
    See Also:
    IndexWriterConfig.setInfoStream(InfoStream)
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class LiveIndexWriterConfig

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

delPolicy

commit

openMode

similarity

mergeScheduler

writeLockTimeout

indexingChain

codec

infoStream

mergePolicy

indexerThreadPool

readerPooling

flushPolicy

perThreadHardLimitMB

matchVersion

Method Detail

getAnalyzer

setTermIndexInterval

getTermIndexInterval

setMaxBufferedDeleteTerms

getMaxBufferedDeleteTerms

setRAMBufferSizeMB

getRAMBufferSizeMB

setMaxBufferedDocs

getMaxBufferedDocs

setMergedSegmentWarmer

getMergedSegmentWarmer

setReaderTermsIndexDivisor

getReaderTermsIndexDivisor

getOpenMode

getIndexDeletionPolicy

getIndexCommit

getSimilarity

getMergeScheduler

getWriteLockTimeout

getCodec

getMergePolicy

getMaxThreadStates

getReaderPooling

getRAMPerThreadHardLimitMB

getInfoStream

toString