The workspace configuration is specified in the Jackrabbit repository configuration file. The configuration specified there acts as a template for the configuration of all new workspaces. Once the workspace is created you can then adjust the workspace configuration on a workspace-by-workspace basis. For example, you can adjust the search index configuration on the workspace to optimize how the data is indexed based on what you know about the data and how it's organized.
The search index in Jackrabbit is pluggable and has a default implementation based on Apache Lucene. It is configured in the file
workspace.xml when the workspace is created. You have a lot of options for configuration. It's the goal of this page to outline those options in one place. This page is based on Jackrabbit 2.16 API, Lucene 3.6, and Magnolia 5.7.
Feel free to ask questions at the bottom of the page for further clarification.
For each workspace that was created, there will also be a
workspace.xml file created inside the workspace home directory that will be used for the workspace.
The virtual file system used by the search index.
The persistence manager configuration for the search index.
Node names and property values are indexed as soon as the data is saved or as soon as the transaction is committed.
Text extraction is done asynchronously in a in a background thread. That means changed or added text is not available immediately, but after a short delay. The exact behavior can be configured using the extractor* settings.
Jackrabbit provides the following options in the class
path: The location of the index directory. This parameter is mandatory. A reasonable value is:
indexingConfiguration: The default indexing configuration file is located in the core module. You have the option to create a workspace specific file with this setting. See Search Index Configuration File.
The configuration parameter
indexingConfigurationis not set by default. This means all properties of a node are indexed.
analyzer: Sets the default analyzer in use for indexing. The default value is the
StandardAnalyzeruses an English language stop word set. Lucene provides language specific analyzers that can be configured on a property-by-property basis in the indexing configuration file.
directoryManager: The name of the class that implements
FSDirectoryManagerimplements a directory manager for
RAMDirectoryManagerimplements a directory manager for
useSimpleFSDirectory: Indicates whether the
DirectoryManagershould use the
SimpleFSDirectoryinstead of letting Lucene automatically pick an implementation based on the platform we are running on. Default is
useCompoundFile: All files belonging to a segment have the same name with varying extensions. When using the Compound File format these files are collapsed into a single
.cfsfile. Useful for systems that frequently run out of file handles.
minMergeDocs: This setting no longer exists in Lucene 3.x.
volatileIdleTime: The Lucene indexer does not write changes to the permanent index immediately. At first, indexer writes the changes to a volatile index. Once the volatile index reaches a certain size it is persisted to the permanent index. Also there is the option to set a timer, in seconds, to control how often changes are written.
maxMergeDocs: While merging segments, Lucene will ensure that no segment with more than maxMergeDocs is created.
mergeFactor: This value tells Lucene how many documents to store in memory before writing them to the disk, as well as how often to merge multiple segments together. With the default value of 10, Lucene will store 10 documents in memory before writing them to a single segment on the disk.
maxFieldLength: Deprecated in Lucene 3.x.
bufferSize: Maximum number of documents that are held in a pending queue until added to the index.
cacheSize: Size of the document number cache. This cache maps UUIDs to lucene document numbers. If the doc number cache hits are poor then increasing this number could help.
maxVolatileIndexSize: The maximum volatile index size in bytes until it is written to disk. The default value is 1MB.
maxHistoryAge: The maximum age (in seconds) of the index history. The default value is 0. Which means, index commits are deleted as soon as they are not used anymore.
initializeHierarchyCache: With the default value of
truethe hierarchy cache is initialized on startup and control is only given back when the initialization has completed. When set to
falsethe cache is populated during regular use.
forceConsistencyCheck: Runs a consistency check on every startup. If false, a consistency check is only performed when the search index detects a prior forced shutdown. When a consistency check is performed it can delay the start of the system. So this should only be run when a search index inconsistency is suspected. For example, a node not found error. A UUID exists in the search index but the corresponding node is not found. On the other hand, a node exists but is not recorded in the index. In both cases the index is inconsistent with the data.
autoRepair: Errors detected by a consistency check are automatically repaired. If false, errors are only written to the log.
enableConsistencyCheck: If set to
truea consistency check is performed depending on the parameter
forceConsistencyCheck. If set to
falseno consistency check is performed on startup, even if a redo log had been applied.
redoLogFactoryClass: The name of the class that implements
RedoLogFactory. A redo log keeps track of changes that have not been committed to disk. While nodes are added to and removed from the volatile index (held in memory) a redo log is maintained to keep track of the changes. In case the Jackrabbit process terminates unexpectedly the redo log is applied when Jackrabbit is restarted the next time.
DefaultRedoLogFactoryis the default value.
queryClass: Class used to perform JCR Queries.
QueryImplprovides the default implementation for a JCR query. Raising the log level on
DEBUGwill print query execution times to the log.
respectDocumentOrder: If true and the query does not contain an 'order by' clause, result nodes will be in document order (the order in which the were indexed by the system).
resultFetchSize: The number of results the query handler should initially fetch when a query is executed. Keep in mind that ACL checks must be performed on the result set. The larger the set the more time to load and check.
TermInfosReaderso that on opening a reader you could further sub-sample the the
termIndexIntervalto use less RAM. Set to 1 by default, meaning all terms loaded into RAM. Set to 2 will load every other term into RAM but the trade off is you might have to scan twice. See LUCENE-1052.
extractorPoolSize: Defines the maximum number of background threads that are used to extract text from binary properties. If set to 0 then no background threads are allocated and text extractors run in the current thread. 1.5 to 2 times the number of processors is a good rule of thumb.
extractorTimeout: A text extractor is executed using a background thread if it doesn't finish within this timeout defined in milliseconds. This parameter has no effect if
extractorBackLogSize: The size of the extractor pool back log. If all threads in the pool are busy, incoming work is put into a wait queue. If the wait queue reaches the back log size, incoming extractor work will not be queued anymore but will be executed with the current thread.
maxExtractLength: Positive values are used as-is, negative values are interpreted as factors of the
forkJavaCommand: Java command used to fork external parser processes or null (the default) for in-process text extraction. Use this to better control system stability and reliability by forcing indexing of binary documents into separate JVM processes. Any problems caused by parsing large or malformed documents won't affect the main process.
nice java -Xmx512m
cmd /c start /low /wait /b java -Xmx512m
Search Term Identification
supportHighlighting: If set to
trueadditional information is stored in the index to support highlighting using the
excerptProviderClass: The name of the class that implements
ExcerptProviderand should be used for the
rep:excerpt()function in a query. By default this is set to
textFilterClasses: Deprecated in Jackrabbit 2.x. With Jackrabbit 2.x Apache Tika was introduced as the default binaries parser. By default Jackrabbit comes with a default
tika-config.xmlfile that contains the configuration for which mime-types to parse and extract.
tikaConfigPath: Set the location of the
tika-config.xml. For example,
This allows users to use generalized language-dependent synonyms but more importantly very domain-specific synonyms like abbreviations or product names.
synonymProviderClass: The name of a class that implements
SynonymProvider. The default value is null which means no class set. Jackrabbit provides the
PropertiesSynonymProviderwhich implements a synonym provider based on a properties file. The location of the properties file is specified by the
synonymProviderConfigPath: The path to the synonym provider configuration file. This path interpreted relative to the
pathparameter. If there is a
FileSystemelement inside the
SearchIndexelement, then this path is interpreted relative to the root path of the
FileSystem. Whether this parameter is mandatory depends on the synonym provider implementation. The default value is null which means no class set.
spellCheckerClass: The name of a class that implements
SpellChecker. No known implementation exists.
Similarity defines the components of Lucene scoring.
similarityClass: The name of a class that extends
Workspace security is handled by the
MagnoliaAccessProvider. See Jackrabbit Repository Configuration File#WorkspaceSecurity.