Apache Solr Reference Guide Covering Apache Solr 6.0

lockType
The LockFactory options specify the locking implementation to use.
The set of valid lock type options depends on the DirectoryFactory you have configured. The values listed
below are are supported by StandardDirectoryFactory (the default):
native (default) uses NativeFSLockFactory to specify native OS file locking. If a second Solr process
attempts to access the directory, it will fail. Do not use when multiple Solr web applications are
attempting to share a single index.
simple uses SimpleFSLockFactory to specify a plain file for locking.
single (expert) uses SingleInstanceLockFactory. Use for special situations of a read-only index
directory, or when there is no possibility of more than one process trying to modify the index (even
sequentially). This type will protect against multiple cores within the same JVM attempting to access
the same index. WARNING! If multiple Solr instances in different JVMs modify an index, this type will n
ot protect against index corruption.
hdfs uses HdfsLockFactory to support reading and writing index and transaction log files to a HDFS
filesystem. See the section Running Solr on HDFS for more details on using this feature.
For more information on the nuances of each LockFactory, see http://wiki.apache.org/lucene-java/AvailableLo
ckFactories.
native
writeLockTimeout
The maximum time to wait for a write lock on an IndexWriter. The default is 1000, expressed in milliseconds.
1000
Other Indexing Settings
There are a few other parameters that may be important to configure for your implementation. These settings
affect how or when updates are made to an index.
Setting
reopenReaders
deletionPolicy
infoStream
Description
Controls if IndexReaders will be re-opened, instead of closed and then opened, which is
often less efficient. The default is true.
Controls how commits are retained in case of rollback. The default is SolrDeletionPo
licy, which has sub-parameters for the maximum number of commits to keep ( maxCom
mitsToKeep), the maximum number of optimized commits to keep ( maxOptimizedCom
mitsToKeep), and the maximum age of any commit to keep ( maxCommitAge), which
supports DateMathParser syntax.
The InfoStream setting instructs the underlying Lucene classes to write detailed debug
information from the indexing process as Solr log messages.
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