org.apache.lucene.index

Interface TwoPhaseCommit

All Known Implementing Classes:

IndexWriter

public interface TwoPhaseCommit

An interface for implementations that support 2-phase commit. You can use TwoPhaseCommitTool to execute a 2-phase commit algorithm over several TwoPhaseCommits.

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

Method Summary

Modifier and Type	Method and Description
long	commit() The second phase of a 2-phase commit.
long	prepareCommit() The first stage of a 2-phase commit.
void	rollback() Discards any changes that have occurred since the last commit.

Method Detail

prepareCommit

long prepareCommit()
            throws IOException

The first stage of a 2-phase commit. Implementations should do as much work as possible in this method, but avoid actual committing changes. If the 2-phase commit fails, rollback() is called to discard all changes since last successful commit.

Throws:

IOException

commit

long commit()
     throws IOException

The second phase of a 2-phase commit. Implementations should ideally do very little work in this method (following prepareCommit(), and after it returns, the caller can assume that the changes were successfully committed to the underlying storage.

Throws:

IOException

rollback

void rollback()
       throws IOException

Discards any changes that have occurred since the last commit. In a 2-phase commit algorithm, where one of the objects failed to commit() or prepareCommit(), this method is used to roll all other objects back to their previous state.

Throws:

IOException