org.corfudb.runtime.view

Class LayoutManagementView

java.lang.Object

org.corfudb.runtime.view.AbstractView

org.corfudb.runtime.view.LayoutManagementView

public class LayoutManagementView
extends AbstractView

A view of the Layout Manager to manage reconfigurations of the Corfu Cluster.

Created by zlokhandwala on 11/1/17.

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
LayoutManagementView(CorfuRuntime runtime)

Method Summary

Modifier and Type	Method and Description
void	addLogUnitReplica(Layout currentLayout, String endpoint, int stripeIndex) Add the log unit to the segment to increase redundancy.
void	addNode(Layout currentLayout, String endpoint, boolean isLayoutServer, boolean isSequencerServer, boolean isLogUnitServer, boolean isUnresponsiveServer, int logUnitStripeIndex) Adds a new node to the existing layout.
CompletableFuture<Boolean>	asyncSequencerBootstrap(Layout layout, ExecutorService service) Triggers a new task to bootstrap the sequencer for the specified layout.
boolean	attemptClusterRecovery(Layout recoveryLayout) On restart, if MANAGEMENT_LAYOUT exists in the local datastore.
CompletableFuture<Boolean>	bootstrapNewNode(String endpoint) Bootstraps the new node with the current layout.
void	forceLayout(Layout currentLayout, Layout forceLayout) Attempts to force commit a new layout to the cluster.
void	handleFailure(IReconfigurationHandlerPolicy failureHandlerPolicy, Layout currentLayout, Set<String> failedServers) Takes in the existing layout and a set of failed nodes.
void	healNode(Layout currentLayout, String endpoint) Heals an existing node in the layout.
void	mergeSegments(Layout currentLayout) Attempts to merge the last 2 segments.
void	reconfigureSequencerServers(Layout originalLayout, Layout newLayout, boolean forceReconfigure) Reconfigures the sequencer.
void	removeNode(Layout currentLayout, String endpoint) Best effort attempt to removes a node from the 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

LayoutManagementView

public LayoutManagementView(@NonNull
                            CorfuRuntime runtime)

Method Detail

attemptClusterRecovery

public boolean attemptClusterRecovery(Layout recoveryLayout)

On restart, if MANAGEMENT_LAYOUT exists in the local datastore. the Management Server attempts to recover the cluster from that layout.

Parameters:

recoveryLayout - Layout to use to recover

Returns:

True if the cluster was recovered, False otherwise

handleFailure

public void handleFailure(IReconfigurationHandlerPolicy failureHandlerPolicy,
                          Layout currentLayout,
                          Set<String> failedServers)
                   throws OutrankedException,
                          LayoutModificationException

Takes in the existing layout and a set of failed nodes. It first generates a new layout by removing the failed nodes from the existing layout. It then seals the epoch to prevent any client from accessing the stale layout. Finally we run paxos to update all servers with the new layout.

Parameters:

currentLayout - The current layout

failedServers - Set of failed server addresses

Throws:

OutrankedException

LayoutModificationException

bootstrapNewNode

public CompletableFuture<Boolean> bootstrapNewNode(String endpoint)

Bootstraps the new node with the current layout. This action is invoked as a part of the add node workflow which requires the new node to be added to the cluster to be bootstrapped with the existing layout of this cluster. This bootstraps the Layout and the Management server with the existing layout which initiates failure handling capabilities on the management server.

Parameters:

endpoint - New node endpoint.

Returns:

Completable Future which completes when the node's layout and management servers are bootstrapped.

addNode

public void addNode(@Nonnull
                    Layout currentLayout,
                    @Nonnull
                    String endpoint,
                    boolean isLayoutServer,
                    boolean isSequencerServer,
                    boolean isLogUnitServer,
                    boolean isUnresponsiveServer,
                    int logUnitStripeIndex)
             throws OutrankedException

Adds a new node to the existing layout.

Parameters:

currentLayout - Current layout.

endpoint - New endpoint to be added.

isLayoutServer - is a layout server

isSequencerServer - is a sequencer server

isLogUnitServer - is a log unit server

isUnresponsiveServer - is an unresponsive server

logUnitStripeIndex - stripe index to be added into if its a log unit.

Throws:

OutrankedException - if consensus outranked.

healNode

public void healNode(Layout currentLayout,
                     String endpoint)
              throws OutrankedException

Heals an existing node in the layout.

Parameters:

currentLayout - Current layout.

endpoint - New endpoint to be added.

Throws:

OutrankedException - if consensus outranked.

mergeSegments

public void mergeSegments(Layout currentLayout)
                   throws OutrankedException

Attempts to merge the last 2 segments.

Parameters:

currentLayout - Current layout

Throws:

OutrankedException - if consensus is outranked.

addLogUnitReplica

public void addLogUnitReplica(@Nonnull
                              Layout currentLayout,
                              @Nonnull
                              String endpoint,
                              int stripeIndex)
                       throws OutrankedException

Add the log unit to the segment to increase redundancy. This is preceded by state transfer. Adds the specified log unit to the stripe in all segments, increments the epoch and proposes the new layout. This method is idempotent - adds the new log unit to each segment only once.

Parameters:

currentLayout - Current layout.

endpoint - Endpoint to be added to the segment.

stripeIndex - Stripe index.

Throws:

OutrankedException - if consensus is outranked.

removeNode

public void removeNode(@Nonnull
                       Layout currentLayout,
                       @Nonnull
                       String endpoint)
                throws OutrankedException

Best effort attempt to removes a node from the layout.

Parameters:

currentLayout - the layout to remove the node from

endpoint - the node to remove

Throws:

OutrankedException

forceLayout

public void forceLayout(@Nonnull
                        Layout currentLayout,
                        @Nonnull
                        Layout forceLayout)

Attempts to force commit a new layout to the cluster.

Parameters:

currentLayout - the current layout

forceLayout - the new layout to force

Throws:

QuorumUnreachableException

reconfigureSequencerServers

public void reconfigureSequencerServers(Layout originalLayout,
                                        Layout newLayout,
                                        boolean forceReconfigure)

Reconfigures the sequencer. If the primary sequencer has changed in the new layout, the global tail of the log units are queried and used to set the initial token of the new primary sequencer.

Parameters:

originalLayout - Current layout to get the latest state of servers.

newLayout - New Layout to be reconfigured.

forceReconfigure - Flag to force reconfiguration.

asyncSequencerBootstrap

public CompletableFuture<Boolean> asyncSequencerBootstrap(@NonNull
                                                          Layout layout,
                                                          @NonNull
                                                          ExecutorService service)

Triggers a new task to bootstrap the sequencer for the specified layout. If there is already a task in progress, this is a no-op.

Parameters:

layout - Layout to use to bootstrap the primary sequencer.

Returns:

Future which completes when the task completes successfully or with a failure.