com.bigdata.ha

Interface HACommitGlue

All Superinterfaces:

Remote

All Known Subinterfaces:

HAGlue

All Known Implementing Classes:

AbstractJournal.BasicHA

public interface HACommitGlue
extends Remote

A Remote interface supporting a 2-phase commit protocol for the members of a highly available quorum.

Version:

$Id$

Author:

Bryan Thompson

See Also:

QuorumCommit

Method Summary

Methods

Modifier and Type	Method and Description
Future<Void>	abort2Phase(IHA2PhaseAbortMessage abortMessage) Discard the current write set using AbstractJournal.abort(), reloading all state from the last root block, etc.
Future<Void>	commit2Phase(IHA2PhaseCommitMessage commitMessage) Commit using the root block from the corresponding prepare message.
Future<Boolean>	prepare2Phase(IHA2PhasePrepareMessage prepareMessage) Save a reference to the caller's root block, flush writes to the backing channel and acknowledge "yes" if ready to commit.

Method Detail

prepare2Phase

Future<Boolean> prepare2Phase(IHA2PhasePrepareMessage prepareMessage)
                              throws IOException

Save a reference to the caller's root block, flush writes to the backing channel and acknowledge "yes" if ready to commit. If the node can not prepare for any reason, then it must return "no".

Parameters:

prepareMessage - The message used to prepare for the commit.

Returns:

A Future which evaluates to a yes/no vote on whether the service is prepared to commit.

Throws:

IOException

commit2Phase

Future<Void> commit2Phase(IHA2PhaseCommitMessage commitMessage)
                          throws IOException

Commit using the root block from the corresponding prepare message. It is an error if a commit message is observed without the corresponding prepare message.

Parameters:

commitMessage - The commit message.

Throws:

IOException

abort2Phase

Future<Void> abort2Phase(IHA2PhaseAbortMessage abortMessage)
                         throws IOException

Discard the current write set using AbstractJournal.abort(), reloading all state from the last root block, etc.

Note: A service automatically does a local abort() if it leaves the pool of services joined with the quorum or if the leader fails over. Therefore a service should reject this message if the token has been invalidated since the service either has dine or will shortly do a low-level abort() on its own initiative.

Parameters:

token - The token for the quorum for which this request was made.

Throws:

IOException