Class IndexReplicationHandler

A IReplicationHandler for replication of an index. Implements RevisionReady(string, IDictionary<string, IList<RevisionFile>>, IDictionary<string, IList<string>>, IDictionary<string, Directory>) by copying the files pointed by the client resolver to the index Lucene.Net.Store.Directory and then touches the index with Lucene.Net.Index.IndexWriter to make sure any unused files are deleted.

Inheritance

object

IndexReplicationHandler

Implements

IReplicationHandler

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Replicator

Assembly: Lucene.Net.Replicator.dll

Syntax

public class IndexReplicationHandler : IReplicationHandler

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Constructors

IndexReplicationHandler(Directory, Action)

Constructor with the given index directory and callback to notify when the indexes were updated.

Declaration

public IndexReplicationHandler(Directory indexDirectory, Action callback)

Parameters

Type	Name	Description
Directory	indexDirectory
Action	callback

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Fields

INFO_STREAM_COMPONENT

The component used to log messages to the Lucene.Net.Util.InfoStream.DefaultLucene.Net.Util.InfoStream.

Declaration

public const string INFO_STREAM_COMPONENT = "IndexReplicationHandler"

Field Value

Type	Description
string

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Properties

CurrentRevisionFiles

Returns the current revision version held by the handler.

Declaration

public virtual IDictionary<string, IList<RevisionFile>> CurrentRevisionFiles { get; }

Property Value

Type	Description
IDictionary<string, IList<RevisionFile>>

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

CurrentVersion

Returns the current revision files held by the handler.

Declaration

public virtual string CurrentVersion { get; }

Property Value

Type	Description
string

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

InfoStream

Gets or sets the Lucene.Net.Util.InfoStream to use for logging messages.

Declaration

public virtual InfoStream InfoStream { get; set; }

Property Value

Type	Description
InfoStream

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Methods

CleanupFilesOnFailure(Directory, IList<string>)

Cleanup the index directory by deleting all given files. Called when file copy or sync failed.

Declaration

public static void CleanupFilesOnFailure(Directory directory, IList<string> files)

Parameters

Type	Name	Description
Directory	directory
IList<string>	files

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

CleanupOldIndexFiles(Directory, string)

Cleans up the index directory from old index files. This method uses the last commit found by GetLastCommit(Directory). If it matches the expected segmentsFile, then all files not referenced by this commit point are deleted.

Declaration

public static void CleanupOldIndexFiles(Directory directory, string segmentsFile)

Parameters

Type	Name	Description
Directory	directory
string	segmentsFile

Remarks

NOTE: This method does a best effort attempt to clean the index directory. It suppresses any exceptions that occur, as this can be retried the next time.

CopyFiles(Directory, Directory, IList<string>)

Copies the provided list of files from the sourceLucene.Net.Store.Directory to the targetLucene.Net.Store.Directory, if they are not the same.

Declaration

public static void CopyFiles(Directory source, Directory target, IList<string> files)

Parameters

Type	Name	Description
Directory	source
Directory	target
IList<string>	files

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Exceptions

Type	Condition
IOException

GetLastCommit(Directory)

Returns the last Lucene.Net.Index.IndexCommit found in the Lucene.Net.Store.Directory, or null if there are no commits.

Declaration

public static IndexCommit GetLastCommit(Directory directory)

Parameters

Type	Name	Description
Directory	directory

Returns

Type	Description
IndexCommit

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Exceptions

Type	Condition
IOException

GetSegmentsFile(IList<string>, bool)

Verifies that the last file is segments_N and fails otherwise. It also removes and returns the file from the list, because it needs to be handled last, after all files. This is important in order to guarantee that if a reader sees the new segments_N, all other segment files are already on stable storage.

The reason why the code fails instead of putting segments_N file last is that this indicates an error in the IRevision implementation.

Declaration

public static string GetSegmentsFile(IList<string> files, bool allowEmpty)

Parameters

Type	Name	Description
IList<string>	files
bool	allowEmpty

Returns

Type	Description
string

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

RevisionReady(string, IDictionary<string, IList<RevisionFile>>, IDictionary<string, IList<string>>, IDictionary<string, Directory>)

Called when a new revision was obtained and is available (i.e. all needed files were successfully copied).

Declaration

public virtual void RevisionReady(string version, IDictionary<string, IList<RevisionFile>> revisionFiles, IDictionary<string, IList<string>> copiedFiles, IDictionary<string, Directory> sourceDirectory)

Parameters

Type	Name	Description
string	version	The version of the IRevision that was copied
IDictionary<string, IList<RevisionFile>>	revisionFiles	The files contained by this IRevision
IDictionary<string, IList<string>>	copiedFiles	The files that were actually copied
IDictionary<string, Directory>	sourceDirectory	A mapping from a source of files to the Lucene.Net.Store.Directory they were copied into

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Exceptions

Type	Condition
IOException

WriteSegmentsGen(string, Directory)

Writes Lucene.Net.Index.IndexFileNames.SEGMENTS_GEN file to the directory, reading the generation from the given segmentsFile. If it is null, this method deletes segments.gen from the directory.

Declaration

public static void WriteSegmentsGen(string segmentsFile, Directory directory)

Parameters

Type	Name	Description
string	segmentsFile
Directory	directory

Remarks

NOTE: This handler assumes that Lucene.Net.Index.IndexWriter is not opened by another process on the index directory. In fact, opening an Lucene.Net.Index.IndexWriter on the same directory to which files are copied can lead to undefined behavior, where some or all the files will be deleted, override other files or simply create a mess. When you replicate an index, it is best if the index is never modified by Lucene.Net.Index.IndexWriter, except the one that is open on the source index, from which you replicate.

This handler notifies the application via a provided Action when an updated index commit was made available for it.

Note

This API is experimental and might change in incompatible ways in the next release.

Implements

IReplicationHandler