io.aeron.cluster

Class ClusterMember

java.lang.Object

io.aeron.cluster.ClusterMember

public final class ClusterMember
extends Object

Represents a member of the cluster that participates in consensus for storing state from the perspective of any single member. It is not a global view of the cluster, perspectives only exist from a vantage point.

Constructor Summary

Constructors

Constructor and Description
ClusterMember(int id, String ingressEndpoint, String consensusEndpoint, String logEndpoint, String catchupEndpoint, String archiveEndpoint, String endpoints) Construct a new member of the cluster.

Method Summary

Modifier and Type	Method and Description
static void	addClusterMemberIds(ClusterMember[] clusterMembers, Int2ObjectHashMap<ClusterMember> clusterMemberByIdMap) Populate map of ClusterMembers which can be looked up by id.
static void	addConsensusPublication(ClusterMember member, String channelTemplate, int streamId, Aeron aeron, ErrorHandler errorHandler) Add an exclusive Publication for communicating to a member on the consensus channel.
static void	addConsensusPublications(ClusterMember[] members, ClusterMember exclude, String channelTemplate, int streamId, Aeron aeron, ErrorHandler errorHandler) Add the publications for sending consensus messages to the other members of the cluster.
static ClusterMember[]	addMember(ClusterMember[] oldMembers, ClusterMember newMember) Add a new member to an array of ClusterMembers.
String	archiveEndpoint() The address:port endpoint for this cluster member that the archive can be reached.
static boolean	areSameEndpoints(ClusterMember lhs, ClusterMember rhs) Are two cluster members using the same endpoints?
static void	becomeCandidate(ClusterMember[] members, long candidateTermId, int candidateMemberId) Become a candidate by voting for yourself and resetting the other votes to Aeron.NULL_VALUE.
long	candidateTermId() The candidate term id used when voting.
ClusterMember	candidateTermId(long candidateTermId) The candidate term id used when voting.
String	catchupEndpoint() The address:port endpoint for this cluster member to which a stream is replayed for catchup to the leader.
long	catchupReplayCorrelationId() The correlation id for the replay when catching up to the leader.
ClusterMember	catchupReplayCorrelationId(long correlationId) The correlation id for the replay when catching up to the leader.
long	catchupReplaySessionId() The session id for the replay when catching up to the leader.
ClusterMember	catchupReplaySessionId(long replaySessionId) The session id for the replay when catching up to the leader.
static void	closeConsensusPublications(ErrorHandler errorHandler, ClusterMember[] clusterMembers) Close the publications associated with members of the cluster used for the consensus protocol.
void	closePublication(ErrorHandler errorHandler) Close consensus publication and null out reference.
static int	compareLog(ClusterMember lhs, ClusterMember rhs) The result is positive if lhs has the more recent log, zero if logs are equal, and negative if rhs has the more recent log.
static int	compareLog(long lhsLogLeadershipTermId, long lhsLogPosition, long rhsLogLeadershipTermId, long rhsLogPosition) The result is positive if lhs has the more recent log, zero if logs are equal, and negative if rhs has the more recent log.
String	consensusEndpoint() The address:port endpoint for this cluster member that other members connect to for achieving consensus.
static void	copyVotes(ClusterMember[] srcMembers, ClusterMember[] dstMembers) Copy votes from one array of members to another where the id()s match.
long	correlationId() Correlation id assigned to the current action undertaken by the cluster member.
ClusterMember	correlationId(long correlationId) Correlation id assigned to the current action undertaken by the cluster member.
static ClusterMember	determineMember(ClusterMember[] clusterMembers, int memberId, String memberEndpoints) Determine which member of a cluster this is and check endpoints.
static String	encodeAsString(ClusterMember[] clusterMembers) Encode member endpoints from a cluster members array to a String.
static String	encodeAsString(List<ClusterMember> clusterMembers) Encode member endpoints from a cluster members List to a String.
String	endpoints() The string of endpoints for this member in a comma separated list in the same order they are parsed.
static ClusterMember	findMember(ClusterMember[] clusterMembers, int memberId) Find a ClusterMember with a given id.
static int	findMemberIndex(ClusterMember[] clusterMembers, int memberId) Find the index at which a member id is present.
static boolean	hasActiveQuorum(ClusterMember[] clusterMembers, long nowNs, long timeoutNs) Check if the cluster leader has an active quorum of cluster followers.
static boolean	hasQuorumAtPosition(ClusterMember[] clusterMembers, long position, long leadershipTermId) Has a quorum of members of appended a position to their local log.
boolean	hasRequestedJoin() Has this member requested to join the cluster?
ClusterMember	hasRequestedJoin(boolean hasRequestedJoin) Set if this member requested to join the cluster.
boolean	hasRequestedRemove() Has this member requested to be removed from the cluster.
boolean	hasTerminated() Has this member notified that it has terminated?
ClusterMember	hasTerminated(boolean hasTerminated) Set if this member has terminated.
static boolean	hasVotersAtPosition(ClusterMember[] clusterMembers, long position, long leadershipTermId) Has the voting members of a cluster arrived at provided position in their log.
static int	highMemberId(ClusterMember[] clusterMembers) Find the highest member id in an array of members.
int	id() Unique identity for this member in the cluster.
ClusterMember	id(int id) Set the unique id for this member of the cluster.
String	ingressEndpoint() The address:port endpoint for this cluster member that clients send ingress to.
static String	ingressEndpoints(ClusterMember[] members) Create a string of ingress endpoints by member id in format id=endpoint,id=endpoint, ....
boolean	isBallotSent() Is the ballot for the current election sent to this member?
ClusterMember	isBallotSent(boolean isBallotSent) Is the ballot for the current election sent to this member?
boolean	isLeader() Is this member currently the leader?
ClusterMember	isLeader(boolean isLeader) Set if this member should be leader.
static boolean	isQuorumCandidate(ClusterMember[] clusterMembers, ClusterMember candidate) Has the member achieved a quorum view to be a suitable candidate in an election.
static boolean	isQuorumLeader(ClusterMember[] clusterMembers, long candidateTermId) Is this member considered leader by a quorum of members by having positive votes being counted for a majority and no negative votes.
static boolean	isUnanimousCandidate(ClusterMember[] clusterMembers, ClusterMember candidate, int gracefulClosedLeaderId) Is the member considered a candidate by a unanimous view to be a suitable candidate in an election.
static boolean	isUnanimousLeader(ClusterMember[] clusterMembers, long candidateTermId, int gracefulClosedLeaderId) Is a member considered unanimously to be leader after voting.
long	leadershipTermId() The leadership term reached for the cluster member.
ClusterMember	leadershipTermId(long leadershipTermId) The leadership term reached for the cluster member.
String	logEndpoint() The address:port endpoint for this cluster member that the log is replicated to.
long	logPosition() The log position this member has persisted.
ClusterMember	logPosition(long logPosition) The log position this member has persisted.
static boolean	notDuplicateEndpoint(ClusterMember[] members, String endpoints) Is the string of member endpoints not duplicated in the members.
static ClusterMember[]	parse(String value) Parse the details for a cluster members from a string.
static ClusterMember	parseEndpoints(int id, String endpoints) Parse a string containing the endpoints for a cluster node and passing to ClusterMember(int, String, String, String, String, String, String).
ExclusivePublication	publication() The Publication used for send status updates to the member.
void	publication(ExclusivePublication publication) Publication used for send status updates to the member.
static long	quorumPosition(ClusterMember[] members, long[] rankedPositions) Calculate the position reached by a quorum of cluster members.
static int	quorumThreshold(int memberCount) The threshold of clusters members required to achieve quorum given a count of cluster members.
long	removalPosition() The log position as of appending the event to be removed from the cluster.
ClusterMember	removalPosition(long removalPosition) Set the log position as of appending the event to be removed from the cluster.
static ClusterMember[]	removeMember(ClusterMember[] oldMembers, int memberId) Remove a member from an array if found, otherwise return the array unmodified.
void	reset() Reset the state of a cluster member, so it can be canvassed and reestablished.
static void	reset(ClusterMember[] members) Reset the state of all cluster members.
static void	resetLogPositions(ClusterMember[] clusterMembers, long logPosition) Reset the log position of all the members to the provided value.
static void	setIsLeader(ClusterMember[] clusterMembers, int leaderMemberId) Run through the list of cluster members and set the isLeader field based on the supplied leaderMemberId.
long	timeOfLastAppendPositionNs() Time (in ns) of last received appendPosition.
ClusterMember	timeOfLastAppendPositionNs(long timeNs) Time (in ns) of last received appendPosition.
String	toString()
static void	tryAddPublication(ClusterMember member, int streamId, Aeron aeron, ErrorHandler errorHandler) Try and add an exclusive Publication for communicating to a member on the consensus channel.
static void	validateMemberEndpoints(ClusterMember member, String memberEndpoints) Check the member with the memberEndpoints.
Boolean	vote() The status of the vote for this member in an election.
ClusterMember	vote(Boolean vote) Set the result of the vote for this member.

Methods inherited from class java.lang.Object

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

Constructor Detail

ClusterMember

public ClusterMember(int id,
                     String ingressEndpoint,
                     String consensusEndpoint,
                     String logEndpoint,
                     String catchupEndpoint,
                     String archiveEndpoint,
                     String endpoints)

Construct a new member of the cluster.

Parameters:

id - unique id for the member.

ingressEndpoint - address and port endpoint to which cluster clients send ingress.

consensusEndpoint - address and port endpoint to which other cluster members connect.

logEndpoint - address and port endpoint to which the log is replicated.

catchupEndpoint - address and port endpoint to which a stream is replayed for catchup to the leader.

archiveEndpoint - address and port endpoint to which the archive control channel can be reached.

endpoints - comma separated list of endpoints.

Method Detail

reset

public void reset()

Reset the state of a cluster member, so it can be canvassed and reestablished.

isLeader

public ClusterMember isLeader(boolean isLeader)

Set if this member should be leader.

Parameters:

isLeader - value.

Returns:

this for a fluent API.

isLeader

public boolean isLeader()

Is this member currently the leader?

Returns:

true if this member is currently the leader otherwise false.

isBallotSent

public ClusterMember isBallotSent(boolean isBallotSent)

Is the ballot for the current election sent to this member?

Parameters:

isBallotSent - is the ballot for the current election sent to this member?

Returns:

this for a fluent API.

isBallotSent

public boolean isBallotSent()

Is the ballot for the current election sent to this member?

Returns:

true if the ballot has been sent for this member in the current election.

hasRequestedJoin

public ClusterMember hasRequestedJoin(boolean hasRequestedJoin)

Set if this member requested to join the cluster.

Parameters:

hasRequestedJoin - the cluster.

Returns:

this for a fluent API.

hasRequestedJoin

public boolean hasRequestedJoin()

Has this member requested to join the cluster?

Returns:

has this member requested to join the cluster?

hasTerminated

public ClusterMember hasTerminated(boolean hasTerminated)

Set if this member has terminated.

Parameters:

hasTerminated - in notification to the leader.

Returns:

this for a fluent API.

hasTerminated

public boolean hasTerminated()

Has this member notified that it has terminated?

Returns:

has this member notified that it has terminated?

removalPosition

public ClusterMember removalPosition(long removalPosition)

Set the log position as of appending the event to be removed from the cluster.

Parameters:

removalPosition - as of appending the event to be removed from the cluster.

Returns:

this for a fluent API.

removalPosition

public long removalPosition()

The log position as of appending the event to be removed from the cluster.

Returns:

the log position as of appending the event to be removed from the cluster, or AeronArchive.NULL_POSITION if not requested remove.

hasRequestedRemove

public boolean hasRequestedRemove()

Has this member requested to be removed from the cluster.

Returns:

true if this member requested to be removed from the cluster, otherwise false.

id

public ClusterMember id(int id)

Set the unique id for this member of the cluster.

Parameters:

id - for this member of the cluster.

Returns:

this for a fluent API.

id

public int id()

Unique identity for this member in the cluster.

Returns:

the unique identity for this member in the cluster.

vote

public ClusterMember vote(Boolean vote)

Set the result of the vote for this member. Boolean.TRUE means they voted for this member, Boolean.FALSE means they voted against this member, and null means no vote was received.

Parameters:

vote - for this member in the election.

Returns:

this for a fluent API.

vote

public Boolean vote()

The status of the vote for this member in an election. Boolean.TRUE means they voted for this member, Boolean.FALSE means they voted against this member, and null means no vote was received.

Returns:

the status of the vote for this member in an election.

leadershipTermId

public ClusterMember leadershipTermId(long leadershipTermId)

The leadership term reached for the cluster member.

Parameters:

leadershipTermId - leadership term reached for the cluster member.

Returns:

this for a fluent API.

leadershipTermId

public long leadershipTermId()

The leadership term reached for the cluster member.

Returns:

The leadership term reached for the cluster member.

logPosition

public ClusterMember logPosition(long logPosition)

The log position this member has persisted.

Parameters:

logPosition - this member has persisted.

Returns:

this for a fluent API.

logPosition

public long logPosition()

The log position this member has persisted.

Returns:

the log position this member has persisted.

candidateTermId

public ClusterMember candidateTermId(long candidateTermId)

The candidate term id used when voting.

Parameters:

candidateTermId - used when voting.

Returns:

this for a fluent API.

candidateTermId

public long candidateTermId()

The candidate term id used when voting.

Returns:

the candidate term id used when voting.

catchupReplaySessionId

public ClusterMember catchupReplaySessionId(long replaySessionId)

The session id for the replay when catching up to the leader.

Parameters:

replaySessionId - for the replay when catching up to the leader.

Returns:

this for a fluent API.

catchupReplaySessionId

public long catchupReplaySessionId()

The session id for the replay when catching up to the leader.

Returns:

the session id for the replay when catching up to the leader.

catchupReplayCorrelationId

public ClusterMember catchupReplayCorrelationId(long correlationId)

The correlation id for the replay when catching up to the leader.

Parameters:

correlationId - for the replay when catching up to the leader.

Returns:

this for a fluent API.

catchupReplayCorrelationId

public long catchupReplayCorrelationId()

The correlation id for the replay when catching up to the leader.

Returns:

the correlation id for the replay when catching up to the leader.

correlationId

public ClusterMember correlationId(long correlationId)

Correlation id assigned to the current action undertaken by the cluster member.

Parameters:

correlationId - assigned to the current action undertaken by the cluster member.

Returns:

this for a fluent API.

correlationId

public long correlationId()

Correlation id assigned to the current action undertaken by the cluster member.

Returns:

correlation id assigned to the current action undertaken by the cluster member.

timeOfLastAppendPositionNs

public ClusterMember timeOfLastAppendPositionNs(long timeNs)

Time (in ns) of last received appendPosition.

Parameters:

timeNs - of the last received appendPosition.

Returns:

this for a fluent API.

timeOfLastAppendPositionNs

public long timeOfLastAppendPositionNs()

Time (in ns) of last received appendPosition.

Returns:

time (in ns) of last received appendPosition or Aeron.NULL_VALUE if none received.

consensusEndpoint

public String consensusEndpoint()

The address:port endpoint for this cluster member that other members connect to for achieving consensus.

Returns:

the address:port endpoint for this cluster member that other members will connect to for consensus.

ingressEndpoint

public String ingressEndpoint()

The address:port endpoint for this cluster member that clients send ingress to.

Returns:

the address:port endpoint for this cluster member that listens for ingress.

logEndpoint

public String logEndpoint()

The address:port endpoint for this cluster member that the log is replicated to.

Returns:

the address:port endpoint for this cluster member that the log is replicated to.

catchupEndpoint

public String catchupEndpoint()

The address:port endpoint for this cluster member to which a stream is replayed for catchup to the leader.

It is recommended a port of 0 is used, so it is system allocated to avoid potential clashes.

Returns:

the address:port endpoint for this cluster member to which a stream is replayed for catchup to the leader.

archiveEndpoint

public String archiveEndpoint()

The address:port endpoint for this cluster member that the archive can be reached.

Returns:

the address:port endpoint for this cluster member that the archive can be reached.

endpoints

public String endpoints()

The string of endpoints for this member in a comma separated list in the same order they are parsed.

Returns:

list of endpoints for this member in a comma separated list.

See Also:

parse(String)

publication

public ExclusivePublication publication()

The Publication used for send status updates to the member.

Returns:

Publication used for send status updates to the member.

publication

public void publication(ExclusivePublication publication)

Publication used for send status updates to the member.

Parameters:

publication - used for send status updates to the member.

closePublication

public void closePublication(ErrorHandler errorHandler)

Close consensus publication and null out reference.

Parameters:

errorHandler - to capture errors during close.

parse

public static ClusterMember[] parse(String value)

Parse the details for a cluster members from a string.

member-id,ingress:port,consensus:port,log:port,catchup:port,archive:port|1,...

Parameters:

value - of the string to be parsed.

Returns:

An array of cluster members.

parseEndpoints

public static ClusterMember parseEndpoints(int id,
                                           String endpoints)

Parse a string containing the endpoints for a cluster node and passing to ClusterMember(int, String, String, String, String, String, String).

Parameters:

id - of the member node.

endpoints - comma separated.

Returns:

the ClusterMember with the endpoints set.

encodeAsString

public static String encodeAsString(ClusterMember[] clusterMembers)

Encode member endpoints from a cluster members array to a String.

Parameters:

clusterMembers - to fill the details from.

Returns:

String representation suitable for use with parse(String).

encodeAsString

public static String encodeAsString(List<ClusterMember> clusterMembers)

Encode member endpoints from a cluster members List to a String.

Parameters:

clusterMembers - to fill the details from.

Returns:

String representation suitable for use with parse(String).

copyVotes

public static void copyVotes(ClusterMember[] srcMembers,
                             ClusterMember[] dstMembers)

Copy votes from one array of members to another where the id()s match.

Parameters:

srcMembers - to copy the votes from.

dstMembers - to copy the votes to.

addConsensusPublications

public static void addConsensusPublications(ClusterMember[] members,
                                            ClusterMember exclude,
                                            String channelTemplate,
                                            int streamId,
                                            Aeron aeron,
                                            ErrorHandler errorHandler)

Add the publications for sending consensus messages to the other members of the cluster.

Parameters:

members - of the cluster.

exclude - this member when adding publications.

channelTemplate - for the publications.

streamId - for the publications.

aeron - to add the publications to.

errorHandler - to log registration exceptions to.

addConsensusPublication

public static void addConsensusPublication(ClusterMember member,
                                           String channelTemplate,
                                           int streamId,
                                           Aeron aeron,
                                           ErrorHandler errorHandler)

Add an exclusive Publication for communicating to a member on the consensus channel.

Parameters:

member - to which the publication is addressed.

channelTemplate - for the target member.

streamId - for the target member.

aeron - from which the publication will be created.

errorHandler - to log registration exceptions to.

tryAddPublication

public static void tryAddPublication(ClusterMember member,
                                     int streamId,
                                     Aeron aeron,
                                     ErrorHandler errorHandler)

Try and add an exclusive Publication for communicating to a member on the consensus channel.

Parameters:

member - to which the publication is added.

streamId - for the target member.

aeron - from which the publication will be created.

errorHandler - to log registration exceptions to.

closeConsensusPublications

public static void closeConsensusPublications(ErrorHandler errorHandler,
                                              ClusterMember[] clusterMembers)

Close the publications associated with members of the cluster used for the consensus protocol.

Parameters:

errorHandler - to capture errors during close.

clusterMembers - to close the publications for.

addClusterMemberIds

public static void addClusterMemberIds(ClusterMember[] clusterMembers,
                                       Int2ObjectHashMap<ClusterMember> clusterMemberByIdMap)

Populate map of ClusterMembers which can be looked up by id.

Parameters:

clusterMembers - to populate the map.

clusterMemberByIdMap - to be populated.

hasActiveQuorum

public static boolean hasActiveQuorum(ClusterMember[] clusterMembers,
                                      long nowNs,
                                      long timeoutNs)

Check if the cluster leader has an active quorum of cluster followers.

Parameters:

clusterMembers - for the current cluster.

nowNs - for the current time.

timeoutNs - after which a follower is not considered active.

Returns:

true if quorum of cluster members are considered active.

quorumThreshold

public static int quorumThreshold(int memberCount)

The threshold of clusters members required to achieve quorum given a count of cluster members.

Parameters:

memberCount - for the cluster

Returns:

the threshold for achieving quorum.

quorumPosition

public static long quorumPosition(ClusterMember[] members,
                                  long[] rankedPositions)

Calculate the position reached by a quorum of cluster members.

Parameters:

members - of the cluster.

rankedPositions - temp array to be used for sorting the positions to avoid allocation.

Returns:

the position reached by a quorum of cluster members.

resetLogPositions

public static void resetLogPositions(ClusterMember[] clusterMembers,
                                     long logPosition)

Reset the log position of all the members to the provided value.

Parameters:

clusterMembers - to be reset.

logPosition - to set for them all.

hasVotersAtPosition

public static boolean hasVotersAtPosition(ClusterMember[] clusterMembers,
                                          long position,
                                          long leadershipTermId)

Has the voting members of a cluster arrived at provided position in their log.

Parameters:

clusterMembers - to check.

position - to compare the logPosition() against.

leadershipTermId - expected of the members.

Returns:

true if all members have reached this position otherwise false.

hasQuorumAtPosition

public static boolean hasQuorumAtPosition(ClusterMember[] clusterMembers,
                                          long position,
                                          long leadershipTermId)

Has a quorum of members of appended a position to their local log.

Parameters:

clusterMembers - to check.

position - to compare the logPosition() against.

leadershipTermId - expected of the members.

Returns:

true if a quorum of members reached this position otherwise false.

reset

public static void reset(ClusterMember[] members)

Reset the state of all cluster members.

Parameters:

members - to reset.

becomeCandidate

public static void becomeCandidate(ClusterMember[] members,
                                   long candidateTermId,
                                   int candidateMemberId)

Become a candidate by voting for yourself and resetting the other votes to Aeron.NULL_VALUE.

Parameters:

members - to reset the votes for.

candidateTermId - for the candidacy.

candidateMemberId - for the election.

isUnanimousLeader

public static boolean isUnanimousLeader(ClusterMember[] clusterMembers,
                                        long candidateTermId,
                                        int gracefulClosedLeaderId)

Is a member considered unanimously to be leader after voting.

If a leader has been gracefully closed then it is not included in the membership for considering a unanimous position but will be considered in the membership for quorum.

Parameters:

clusterMembers - to check for votes.

candidateTermId - for the vote.

gracefulClosedLeaderId - id of a leader if gracefully closed otherwise Aeron.NULL_VALUE.

Returns:

true if all members voted positively.

isQuorumLeader

public static boolean isQuorumLeader(ClusterMember[] clusterMembers,
                                     long candidateTermId)

Is this member considered leader by a quorum of members by having positive votes being counted for a majority and no negative votes.

Parameters:

clusterMembers - to check for votes.

candidateTermId - for the vote.

Returns:

true if sufficient positive votes being counted for a majority and no negative votes.

determineMember

public static ClusterMember determineMember(ClusterMember[] clusterMembers,
                                            int memberId,
                                            String memberEndpoints)

Determine which member of a cluster this is and check endpoints.

Parameters:

clusterMembers - for the current cluster which can be null.

memberId - for this member.

memberEndpoints - for this member.

Returns:

the ClusterMember determined.

validateMemberEndpoints

public static void validateMemberEndpoints(ClusterMember member,
                                           String memberEndpoints)

Check the member with the memberEndpoints.

Parameters:

member - to check memberEndpoints against.

memberEndpoints - to check member against.

See Also:

ConsensusModule.Context.memberEndpoints(), ConsensusModule.Context.clusterMembers()

areSameEndpoints

public static boolean areSameEndpoints(ClusterMember lhs,
                                       ClusterMember rhs)

Are two cluster members using the same endpoints?

Parameters:

lhs - to compare for equality.

rhs - to compare for equality.

Returns:

true if both are using the same endpoints or false if not.

isUnanimousCandidate

public static boolean isUnanimousCandidate(ClusterMember[] clusterMembers,
                                           ClusterMember candidate,
                                           int gracefulClosedLeaderId)

Is the member considered a candidate by a unanimous view to be a suitable candidate in an election.

If a leader has been gracefully closed then it is not included in the membership for considering a unanimous position but will be considered in the membership for quorum.

Parameters:

clusterMembers - to compare the candidate against.

candidate - for leadership.

gracefulClosedLeaderId - id of a leader if gracefully closed otherwise Aeron.NULL_VALUE.

Returns:

true if the candidate is suitable otherwise false.

isQuorumCandidate

public static boolean isQuorumCandidate(ClusterMember[] clusterMembers,
                                        ClusterMember candidate)

Has the member achieved a quorum view to be a suitable candidate in an election.

Parameters:

clusterMembers - to compare the candidate against.

candidate - for leadership.

Returns:

true if the candidate is suitable otherwise false.

compareLog

public static int compareLog(long lhsLogLeadershipTermId,
                             long lhsLogPosition,
                             long rhsLogLeadershipTermId,
                             long rhsLogPosition)

The result is positive if lhs has the more recent log, zero if logs are equal, and negative if rhs has the more recent log.

Parameters:

lhsLogLeadershipTermId - term for which the position is most recent.

lhsLogPosition - reached in the provided term.

rhsLogLeadershipTermId - term for which the position is most recent.

rhsLogPosition - reached in the provided term.

Returns:

positive if lhs has the more recent log, zero if logs are equal, and negative if rhs has the more recent log.

compareLog

public static int compareLog(ClusterMember lhs,
                             ClusterMember rhs)

The result is positive if lhs has the more recent log, zero if logs are equal, and negative if rhs has the more recent log.

Parameters:

lhs - member to compare.

rhs - member to compare.

Returns:

positive if lhs has the more recent log, zero if logs are equal, and negative if rhs has the more recent log.

notDuplicateEndpoint

public static boolean notDuplicateEndpoint(ClusterMember[] members,
                                           String endpoints)

Is the string of member endpoints not duplicated in the members.

Parameters:

members - to check if the provided endpoints have a duplicate.

endpoints - to check for duplicates.

Returns:

true if no duplicate is found otherwise false.

findMemberIndex

public static int findMemberIndex(ClusterMember[] clusterMembers,
                                  int memberId)

Find the index at which a member id is present.

Parameters:

clusterMembers - to be searched.

memberId - to search for.

Returns:

the index at which the member id is found otherwise ArrayUtil.UNKNOWN_INDEX.

findMember

public static ClusterMember findMember(ClusterMember[] clusterMembers,
                                       int memberId)

Find a ClusterMember with a given id.

Parameters:

clusterMembers - to search.

memberId - to search for.

Returns:

the ClusterMember if found otherwise null.

addMember

public static ClusterMember[] addMember(ClusterMember[] oldMembers,
                                        ClusterMember newMember)

Add a new member to an array of ClusterMembers.

Parameters:

oldMembers - to add to.

newMember - to add.

Returns:

a new array containing the old members plus the new member.

removeMember

public static ClusterMember[] removeMember(ClusterMember[] oldMembers,
                                           int memberId)

Remove a member from an array if found, otherwise return the array unmodified.

Parameters:

oldMembers - to remove a member from.

memberId - of the member to remove.

Returns:

a new array with the member removed or the existing array if not found.

highMemberId

public static int highMemberId(ClusterMember[] clusterMembers)

Find the highest member id in an array of members.

Parameters:

clusterMembers - to search for the highest id.

Returns:

the highest id otherwise Aeron.NULL_VALUE if empty.

ingressEndpoints

public static String ingressEndpoints(ClusterMember[] members)

Create a string of ingress endpoints by member id in format id=endpoint,id=endpoint, ....

Parameters:

members - for which the ingress endpoints string will be generated.

Returns:

a string of ingress endpoints by id.

setIsLeader

public static void setIsLeader(ClusterMember[] clusterMembers,
                               int leaderMemberId)

Run through the list of cluster members and set the isLeader field based on the supplied leaderMemberId.

Parameters:

clusterMembers - list of cluster members.

leaderMemberId - memberId of the current leader.

toString

public String toString()

Overrides:

toString in class Object