com.bigdata.ha

Interface HATXSGlue

All Superinterfaces:

Remote

All Known Subinterfaces:

HAGlue

All Known Implementing Classes:

AbstractHATransactionService, AbstractJournal.BasicHA, JournalTransactionService

public interface HATXSGlue
extends Remote

RMI interface for the ITransactionService for HA.

Author:

Bryan Thompson

See Also:

HA TXS Design Document , HA TXS / TXS Bottleneck

Method Summary

Methods

Modifier and Type	Method and Description
void	gatherMinimumVisibleCommitTime(IHAGatherReleaseTimeRequest req) Message used to request information about the earliest commit point that is pinned on a follower.
IHANotifyReleaseTimeResponse	notifyEarliestCommitTime(IHANotifyReleaseTimeRequest req) Message used by the follower to notify the leader about the new release time that will be visible for new transaction starts.

Method Detail

gatherMinimumVisibleCommitTime

void gatherMinimumVisibleCommitTime(IHAGatherReleaseTimeRequest req)
                                    throws IOException

Message used to request information about the earliest commit point that is pinned on a follower. This is used by the leader to make a decision about the new release time for the replication cluster.

Note: This message is used as part of a pattern where the leader instructs the followers to message the leader with their earliest commit point pinned by either a transaction or the minReleaseAge of their ITransactionService using #notifyEarliestCommitTime(IHANotifyReleaseTimeResponse).

The message is a sync RMI call. The follower will clear an outcome and execute a task which runs asynchronously and messages back to the leader with its IHANotifyReleaseTimeResponse. The leader will report back the consensus release time. The outcome of these on the follower is not directly reported back to the leader, e.g., through a remote Future because this causes a DGC thread leak on the follower. See the ticket below. Instead, the follower notes the outcome of the gather operation and will vote "NO" in HACommitGlue.prepare2Phase(IHA2PhasePrepareMessage) unless it completes its side of the release time consensus protocol without error (that is, the otherwise unmonitored outcome of the asynchronous task for gatherMinimumVisibleCommitTime(IHAGatherReleaseTimeRequest)).

Parameters:

req - The request from the leader.

Throws:

IOException

See Also:

#notifyEarliestCommitTime(IHANotifyReleaseTimeResponse), Native thread leak in HAJournalServer process

notifyEarliestCommitTime

IHANotifyReleaseTimeResponse notifyEarliestCommitTime(IHANotifyReleaseTimeRequest req)
                                                      throws IOException,
                                                             InterruptedException,
                                                             BrokenBarrierException

Message used by the follower to notify the leader about the new release time that will be visible for new transaction starts. The leader then chooses the mimimum across itself and the followers.

Parameters:

rsp - The earliest pinned commit point on the follower.

Returns:

The earliest pinned commit point across the services joined with the met quorum.

Throws:

BrokenBarrierException

InterruptedException

IOException