org.corfudb.runtime.view

Class LayoutView

java.lang.Object

org.corfudb.runtime.view.AbstractView

org.corfudb.runtime.view.LayoutView

public class LayoutView
extends AbstractView

Created by mwei on 12/10/15.

Nested Class Summary

Nested classes/interfaces inherited from class org.corfudb.runtime.view.AbstractView

AbstractView.LayoutFunction<V,R,A extends Throwable,B extends Throwable,C extends Throwable,D extends Throwable>

Constructor Summary

Constructors

Constructor and Description
LayoutView(CorfuRuntime runtime)

Method Summary

Modifier and Type	Method and Description
void	committed(long epoch, Layout layout) Send committed layout to the old Layout servers and the new Layout Servers.
void	committed(long epoch, Layout layout, boolean force) Send committed layout to the old Layout servers and the new Layout Servers.
Layout	getLayout() Retrieves current layout.
int	getQuorumNumber() Retrieves the number of nodes needed to obtain a quorum.
RuntimeLayout	getRuntimeLayout()
RuntimeLayout	getRuntimeLayout(Layout layout)
Layout	prepare(long epoch, long rank) Sends prepare to the current layout and can proceed only if it is accepted by a quorum.
Layout	propose(long epoch, long rank, Layout layout) Proposes new layout to all the servers in the current layout.
void	updateLayout(Layout layout, long rank) Drives the consensus protocol for persisting the new Layout.

Methods inherited from class org.corfudb.runtime.view.AbstractView

getCurrentLayout, layoutHelper, layoutHelper

Methods inherited from class java.lang.Object

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

Constructor Detail

LayoutView

public LayoutView(@Nonnull
                  CorfuRuntime runtime)

Method Detail

getLayout

public Layout getLayout()

Retrieves current layout.

getRuntimeLayout

public RuntimeLayout getRuntimeLayout()

getRuntimeLayout

public RuntimeLayout getRuntimeLayout(@Nonnull
                                      Layout layout)

getQuorumNumber

public int getQuorumNumber()

Retrieves the number of nodes needed to obtain a quorum. We define a quorum for the layout view as n/2+1

Returns:

The number of nodes required for a quorum.

updateLayout

public void updateLayout(Layout layout,
                         long rank)
                  throws QuorumUnreachableException,
                         OutrankedException,
                         WrongEpochException

Drives the consensus protocol for persisting the new Layout. TODO currently the code can drive only one Layout change. If it has to drive a previously incomplete round TODO it will drop it's own set of changes. Need to revisit this. A change of layout proposal consists of a rank and the desired layout.

Parameters:

layout - The layout to propose.

rank - The rank for the proposed layout.

Throws:

QuorumUnreachableException - Thrown if responses not received from a majority of layout servers.

OutrankedException - outranked exception, i.e., higher rank.

WrongEpochException - wrong epoch number.

prepare

public Layout prepare(long epoch,
                      long rank)
               throws QuorumUnreachableException,
                      OutrankedException,
                      WrongEpochException

Sends prepare to the current layout and can proceed only if it is accepted by a quorum.

Parameters:

rank - The rank for the proposed layout.

Returns:

layout

Throws:

QuorumUnreachableException - Thrown if responses not received from a majority of layout servers.

OutrankedException - outranked exception, i.e., higher rank.

WrongEpochException - wrong epoch number.

propose

public Layout propose(long epoch,
                      long rank,
                      Layout layout)
               throws QuorumUnreachableException,
                      OutrankedException

Proposes new layout to all the servers in the current layout.

Throws:

QuorumUnreachableException - Thrown if responses not received from a majority of layout servers.

OutrankedException - outranked exception, i.e., higher rank.

committed

public void committed(long epoch,
                      Layout layout)

Send committed layout to the old Layout servers and the new Layout Servers. TODO Current policy is to send the committed layout once. Need to revisit this in order TODO to drive the new layout to all the involved LayoutServers. TODO The new layout servers are not bootstrapped and will reject committed messages. TODO Need to fix this.

Throws:

WrongEpochException - wrong epoch number.

committed

public void committed(long epoch,
                      Layout layout,
                      boolean force)
               throws WrongEpochException

Send committed layout to the old Layout servers and the new Layout Servers. If force is true, then the layout forced on all layout servers.

Throws:

WrongEpochException