Package org.elasticsearch.index.engine

Class CombinedDeletionPolicy

java.lang.Object

org.apache.lucene.index.IndexDeletionPolicy

org.elasticsearch.index.engine.CombinedDeletionPolicy

public final class CombinedDeletionPolicy
extends org.apache.lucene.index.IndexDeletionPolicy

An IndexDeletionPolicy that coordinates between Lucene's commits and the retention of translog generation files, making sure that all translog files that are needed to recover from the Lucene commit are not deleted.

In particular, this policy will delete index commits whose max sequence number is at most the current global checkpoint except the index commit which has the highest max sequence number among those.

Method Summary

Modifier and Type	Method	Description
static java.lang.String	commitDescription(org.apache.lucene.index.IndexCommit commit)	Returns a description for a given IndexCommit.
static org.apache.lucene.index.IndexCommit	findSafeCommitPoint(java.util.List<org.apache.lucene.index.IndexCommit> commits, long globalCheckpoint)	Find a safe commit point from a list of existing commits based on the supplied global checkpoint.
void	onCommit(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)
void	onInit(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

onInit

public void onInit(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)
            throws java.io.IOException

Specified by:

onInit in class org.apache.lucene.index.IndexDeletionPolicy

Throws:

java.io.IOException

onCommit

public void onCommit(java.util.List<? extends org.apache.lucene.index.IndexCommit> commits)
              throws java.io.IOException

Specified by:

onCommit in class org.apache.lucene.index.IndexDeletionPolicy

Throws:

java.io.IOException

findSafeCommitPoint

public static org.apache.lucene.index.IndexCommit findSafeCommitPoint(java.util.List<org.apache.lucene.index.IndexCommit> commits,
                                                                      long globalCheckpoint)
                                                               throws java.io.IOException

Find a safe commit point from a list of existing commits based on the supplied global checkpoint. The max sequence number of a safe commit point should be at most the global checkpoint. If an index was created before v6.2, and we haven't retained a safe commit yet, this method will return the oldest commit.

Parameters:

commits - a list of existing commit points

globalCheckpoint - the persisted global checkpoint from the translog, see Translog.readGlobalCheckpoint(Path, String)

Returns:

a safe commit or the oldest commit if a safe commit is not found

Throws:

java.io.IOException

commitDescription

public static java.lang.String commitDescription(org.apache.lucene.index.IndexCommit commit)
                                          throws java.io.IOException

Returns a description for a given IndexCommit. This should be only used for logging and debugging.

Throws:

java.io.IOException