Package org.apache.activemq.artemis.core.server.impl.quorum

Class ActivationSequenceStateMachine

java.lang.Object

org.apache.activemq.artemis.core.server.impl.quorum.ActivationSequenceStateMachine

public final class ActivationSequenceStateMachine
extends Object

This class contains the activation sequence logic of the pluggable quorum vote: it should be used by ReplicationBackupActivation and ReplicationPrimaryActivation to coordinate for replication.

Method Summary

Modifier and Type	Method	Description
static boolean	awaitNextCommittedActivationSequence(org.apache.activemq.artemis.quorum.DistributedPrimitiveManager distributedManager, String coordinatedLockAndNodeId, long activationSequence, long timeoutMills, org.slf4j.Logger logger)	It wait until timeoutMillis ms has passed or the coordinated activation sequence has progressed enough
static void	ensureSequentialAccessToNodeData(String serverDescription, NodeManager nodeManager, org.apache.activemq.artemis.quorum.DistributedPrimitiveManager distributedManager, org.slf4j.Logger logger)	This is going to increment the coordinated activation sequence and the local activation sequence (using NodeManager.writeNodeActivationSequence(long)) while holding the live lock, failing with some exception otherwise.
static org.apache.activemq.artemis.quorum.DistributedLock	tryActivate(NodeManager nodeManager, org.apache.activemq.artemis.quorum.DistributedPrimitiveManager distributedManager, org.slf4j.Logger logger)	It loops if the data of the broker is still valuable, but cannot become live.

Methods inherited from class java.lang.Object

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

Method Detail

tryActivate

public static org.apache.activemq.artemis.quorum.DistributedLock tryActivate(NodeManager nodeManager,
                                                                             org.apache.activemq.artemis.quorum.DistributedPrimitiveManager distributedManager,
                                                                             org.slf4j.Logger logger)
                                                                      throws InterruptedException,
                                                                             ExecutionException,
                                                                             TimeoutException,
                                                                             org.apache.activemq.artemis.quorum.UnavailableStateException

It loops if the data of the broker is still valuable, but cannot become live. It loops (temporarily) if data is in sync or can auto-repair, but cannot yet acquire the live lock.

It stops loop and return:

• null: if data is stale (and there are no rights to become live)
• !=null: if data is in sync/repaired and the DistributedLock is correctly acquired

After successfully returning from this method ie not null return value, a broker should use ensureSequentialAccessToNodeData(java.lang.String, org.apache.activemq.artemis.core.server.NodeManager, org.apache.activemq.artemis.quorum.DistributedPrimitiveManager, org.slf4j.Logger) to complete the activation and guarantee the initial not-replicated ownership of data.

Throws:

InterruptedException

ExecutionException

TimeoutException

org.apache.activemq.artemis.quorum.UnavailableStateException

awaitNextCommittedActivationSequence

public static boolean awaitNextCommittedActivationSequence(org.apache.activemq.artemis.quorum.DistributedPrimitiveManager distributedManager,
                                                           String coordinatedLockAndNodeId,
                                                           long activationSequence,
                                                           long timeoutMills,
                                                           org.slf4j.Logger logger)
                                                    throws ExecutionException,
                                                           InterruptedException,
                                                           TimeoutException,
                                                           org.apache.activemq.artemis.quorum.UnavailableStateException

It wait until timeoutMillis ms has passed or the coordinated activation sequence has progressed enough

Throws:

ExecutionException

InterruptedException

TimeoutException

org.apache.activemq.artemis.quorum.UnavailableStateException

ensureSequentialAccessToNodeData

public static void ensureSequentialAccessToNodeData(String serverDescription,
                                                    NodeManager nodeManager,
                                                    org.apache.activemq.artemis.quorum.DistributedPrimitiveManager distributedManager,
                                                    org.slf4j.Logger logger)
                                             throws ActiveMQException,
                                                    InterruptedException,
                                                    org.apache.activemq.artemis.quorum.UnavailableStateException,
                                                    ExecutionException,
                                                    TimeoutException

This is going to increment the coordinated activation sequence and the local activation sequence (using NodeManager.writeNodeActivationSequence(long)) while holding the live lock, failing with some exception otherwise.

This must be used while holding a live lock to ensure not-exclusive ownership of data ie can be both used while loosing connectivity with a replica or after successfully tryActivate(org.apache.activemq.artemis.core.server.NodeManager, org.apache.activemq.artemis.quorum.DistributedPrimitiveManager, org.slf4j.Logger).

Throws:

ActiveMQException

InterruptedException

org.apache.activemq.artemis.quorum.UnavailableStateException

ExecutionException

TimeoutException