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 Directory and then touches the index with IndexWriter to make sure any unused files are deleted.

Inheritance

System.Object

IndexReplicationHandler

Implements

IReplicationHandler

Namespace: Lucene.Net.Replicator

Assembly: Lucene.Net.Replicator.dll

Syntax

public class IndexReplicationHandler : object, IReplicationHandler

Remarks

NOTE: This handler assumes that IndexWriter is not opened by another process on the index directory. In fact, opening an 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 IndexWriter, except the one that is open on the source index, from which you replicate.

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

This is a Lucene.NET EXPERIMENTAL API, use at your own risk

Constructors

IndexReplicationHandler(Directory, Func<Nullable<Boolean>>)

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

Declaration

public IndexReplicationHandler(Directory indexDirectory, Func<bool?> callback)

Parameters

Type	Name	Description
Directory	indexDirectory
Func<System.Nullable<System.Boolean>>	callback

Fields

INFO_STREAM_COMPONENT

The component used to log messages to the Default InfoStream.

Declaration

public const string INFO_STREAM_COMPONENT = null

Field Value

Type	Description
System.String

Properties

CurrentRevisionFiles

Declaration

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

Property Value

Type	Description
IDictionary<System.String, IList<RevisionFile>>

CurrentVersion

Declaration

public virtual string CurrentVersion { get; }

Property Value

Type	Description
System.String

InfoStream

Gets or sets the InfoStream to use for logging messages.

Declaration

public virtual InfoStream InfoStream { get; set; }

Property Value

Type	Description
InfoStream

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<System.String>	files

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
System.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 source Directory to the target 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<System.String>	files

GetLastCommit(Directory)

Returns the last IndexCommit found in the 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

GetSegmentsFile(IList<String>, Boolean)

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<System.String>	files
System.Boolean	allowEmpty

Returns

Type	Description
System.String

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

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
System.String	version
IDictionary<System.String, IList<RevisionFile>>	revisionFiles
IDictionary<System.String, IList<System.String>>	copiedFiles
IDictionary<System.String, Directory>	sourceDirectory

WriteSegmentsGen(String, Directory)

Writes 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
System.String	segmentsFile
Directory	directory

Implements

IReplicationHandler