Examples with LeaderState org.apache.kafka.connect.runtime.distributed.WorkerCoordinator.LeaderState used on opensource projects

Example 1 with LeaderState

use of org.apache.kafka.connect.runtime.distributed.WorkerCoordinator.LeaderState in project kafka by apache.

the class IncrementalCooperativeAssignor method performTaskAssignment.

/**
 * Performs task assignment based on the incremental cooperative connect protocol.
 * Read more on the design and implementation in:
 * {@see https://cwiki.apache.org/confluence/display/KAFKA/KIP-415%3A+Incremental+Cooperative+Rebalancing+in+Kafka+Connect}
 *
 * @param leaderId the ID of the group leader
 * @param maxOffset the latest known offset of the configuration topic
 * @param memberConfigs the metadata of all the members of the group as gather in the current
 * round of rebalancing
 * @param coordinator the worker coordinator instance that provide the configuration snapshot
 * and get assigned the leader state during this assignment
 * @param protocolVersion the Connect subprotocol version
 * @return the serialized assignment of tasks to the whole group, including assigned or
 * revoked tasks
 */
protected Map<String, ByteBuffer> performTaskAssignment(String leaderId, long maxOffset, Map<String, ExtendedWorkerState> memberConfigs, WorkerCoordinator coordinator, short protocolVersion) {
    log.debug("Performing task assignment during generation: {} with memberId: {}", coordinator.generationId(), coordinator.memberId());
    // Base set: The previous assignment of connectors-and-tasks is a standalone snapshot that
    // can be used to calculate derived sets
    log.debug("Previous assignments: {}", previousAssignment);
    int lastCompletedGenerationId = coordinator.lastCompletedGenerationId();
    if (previousGenerationId != lastCompletedGenerationId) {
        log.debug("Clearing the view of previous assignments due to generation mismatch between " + "previous generation ID {} and last completed generation ID {}. This can " + "happen if the leader fails to sync the assignment within a rebalancing round. " + "The following view of previous assignments might be outdated and will be " + "ignored by the leader in the current computation of new assignments. " + "Possibly outdated previous assignments: {}", previousGenerationId, lastCompletedGenerationId, previousAssignment);
        this.previousAssignment = ConnectorsAndTasks.EMPTY;
    }
    ClusterConfigState snapshot = coordinator.configSnapshot();
    Set<String> configuredConnectors = new TreeSet<>(snapshot.connectors());
    Set<ConnectorTaskId> configuredTasks = configuredConnectors.stream().flatMap(c -> snapshot.tasks(c).stream()).collect(Collectors.toSet());
    // Base set: The set of configured connectors-and-tasks is a standalone snapshot that can
    // be used to calculate derived sets
    ConnectorsAndTasks configured = new ConnectorsAndTasks.Builder().with(configuredConnectors, configuredTasks).build();
    log.debug("Configured assignments: {}", configured);
    // Base set: The set of active connectors-and-tasks is a standalone snapshot that can be
    // used to calculate derived sets
    ConnectorsAndTasks activeAssignments = assignment(memberConfigs);
    log.debug("Active assignments: {}", activeAssignments);
    // appropriately and be ready to re-apply revocation of tasks
    if (!previousRevocation.isEmpty()) {
        if (previousRevocation.connectors().stream().anyMatch(c -> activeAssignments.connectors().contains(c)) || previousRevocation.tasks().stream().anyMatch(t -> activeAssignments.tasks().contains(t))) {
            previousAssignment = activeAssignments;
            canRevoke = true;
        }
        previousRevocation.connectors().clear();
        previousRevocation.tasks().clear();
    }
    // Derived set: The set of deleted connectors-and-tasks is a derived set from the set
    // difference of previous - configured
    ConnectorsAndTasks deleted = diff(previousAssignment, configured);
    log.debug("Deleted assignments: {}", deleted);
    // Derived set: The set of remaining active connectors-and-tasks is a derived set from the
    // set difference of active - deleted
    ConnectorsAndTasks remainingActive = diff(activeAssignments, deleted);
    log.debug("Remaining (excluding deleted) active assignments: {}", remainingActive);
    // Derived set: The set of lost or unaccounted connectors-and-tasks is a derived set from
    // the set difference of previous - active - deleted
    ConnectorsAndTasks lostAssignments = diff(previousAssignment, activeAssignments, deleted);
    log.debug("Lost assignments: {}", lostAssignments);
    // Derived set: The set of new connectors-and-tasks is a derived set from the set
    // difference of configured - previous - active
    ConnectorsAndTasks newSubmissions = diff(configured, previousAssignment, activeAssignments);
    log.debug("New assignments: {}", newSubmissions);
    // A collection of the complete assignment
    List<WorkerLoad> completeWorkerAssignment = workerAssignment(memberConfigs, ConnectorsAndTasks.EMPTY);
    log.debug("Complete (ignoring deletions) worker assignments: {}", completeWorkerAssignment);
    // Per worker connector assignments without removing deleted connectors yet
    Map<String, Collection<String>> connectorAssignments = completeWorkerAssignment.stream().collect(Collectors.toMap(WorkerLoad::worker, WorkerLoad::connectors));
    log.debug("Complete (ignoring deletions) connector assignments: {}", connectorAssignments);
    // Per worker task assignments without removing deleted connectors yet
    Map<String, Collection<ConnectorTaskId>> taskAssignments = completeWorkerAssignment.stream().collect(Collectors.toMap(WorkerLoad::worker, WorkerLoad::tasks));
    log.debug("Complete (ignoring deletions) task assignments: {}", taskAssignments);
    // A collection of the current assignment excluding the connectors-and-tasks to be deleted
    List<WorkerLoad> currentWorkerAssignment = workerAssignment(memberConfigs, deleted);
    Map<String, ConnectorsAndTasks> toRevoke = computeDeleted(deleted, connectorAssignments, taskAssignments);
    log.debug("Connector and task to delete assignments: {}", toRevoke);
    // Revoking redundant connectors/tasks if the workers have duplicate assignments
    toRevoke.putAll(computeDuplicatedAssignments(memberConfigs, connectorAssignments, taskAssignments));
    log.debug("Connector and task to revoke assignments (include duplicated assignments): {}", toRevoke);
    // Recompute the complete assignment excluding the deleted connectors-and-tasks
    completeWorkerAssignment = workerAssignment(memberConfigs, deleted);
    connectorAssignments = completeWorkerAssignment.stream().collect(Collectors.toMap(WorkerLoad::worker, WorkerLoad::connectors));
    taskAssignments = completeWorkerAssignment.stream().collect(Collectors.toMap(WorkerLoad::worker, WorkerLoad::tasks));
    handleLostAssignments(lostAssignments, newSubmissions, completeWorkerAssignment, memberConfigs);
    // Do not revoke resources for re-assignment while a delayed rebalance is active
    // Also we do not revoke in two consecutive rebalances by the same leader
    canRevoke = delay == 0 && canRevoke;
    // Compute the connectors-and-tasks to be revoked for load balancing without taking into
    // account the deleted ones.
    log.debug("Can leader revoke tasks in this assignment? {} (delay: {})", canRevoke, delay);
    if (canRevoke) {
        Map<String, ConnectorsAndTasks> toExplicitlyRevoke = performTaskRevocation(activeAssignments, currentWorkerAssignment);
        log.debug("Connector and task to revoke assignments: {}", toRevoke);
        toExplicitlyRevoke.forEach((worker, assignment) -> {
            ConnectorsAndTasks existing = toRevoke.computeIfAbsent(worker, v -> new ConnectorsAndTasks.Builder().build());
            existing.connectors().addAll(assignment.connectors());
            existing.tasks().addAll(assignment.tasks());
        });
        canRevoke = toExplicitlyRevoke.size() == 0;
    } else {
        canRevoke = delay == 0;
    }
    assignConnectors(completeWorkerAssignment, newSubmissions.connectors());
    assignTasks(completeWorkerAssignment, newSubmissions.tasks());
    log.debug("Current complete assignments: {}", currentWorkerAssignment);
    log.debug("New complete assignments: {}", completeWorkerAssignment);
    Map<String, Collection<String>> currentConnectorAssignments = currentWorkerAssignment.stream().collect(Collectors.toMap(WorkerLoad::worker, WorkerLoad::connectors));
    Map<String, Collection<ConnectorTaskId>> currentTaskAssignments = currentWorkerAssignment.stream().collect(Collectors.toMap(WorkerLoad::worker, WorkerLoad::tasks));
    Map<String, Collection<String>> incrementalConnectorAssignments = diff(connectorAssignments, currentConnectorAssignments);
    Map<String, Collection<ConnectorTaskId>> incrementalTaskAssignments = diff(taskAssignments, currentTaskAssignments);
    log.debug("Incremental connector assignments: {}", incrementalConnectorAssignments);
    log.debug("Incremental task assignments: {}", incrementalTaskAssignments);
    coordinator.leaderState(new LeaderState(memberConfigs, connectorAssignments, taskAssignments));
    Map<String, ExtendedAssignment> assignments = fillAssignments(memberConfigs.keySet(), Assignment.NO_ERROR, leaderId, memberConfigs.get(leaderId).url(), maxOffset, incrementalConnectorAssignments, incrementalTaskAssignments, toRevoke, delay, protocolVersion);
    previousAssignment = computePreviousAssignment(toRevoke, connectorAssignments, taskAssignments, lostAssignments);
    previousGenerationId = coordinator.generationId();
    previousMembers = memberConfigs.keySet();
    log.debug("Actual assignments: {}", assignments);
    return serializeAssignments(assignments);
}

Example 2 with LeaderState

use of org.apache.kafka.connect.runtime.distributed.WorkerCoordinator.LeaderState in project kafka by apache.

the class EagerAssignor method performTaskAssignment.

private Map<String, ByteBuffer> performTaskAssignment(String leaderId, long maxOffset, Map<String, ExtendedWorkerState> memberConfigs, WorkerCoordinator coordinator) {
    Map<String, Collection<String>> connectorAssignments = new HashMap<>();
    Map<String, Collection<ConnectorTaskId>> taskAssignments = new HashMap<>();
    // Perform round-robin task assignment. Assign all connectors and then all tasks because assigning both the
    // connector and its tasks can lead to very uneven distribution of work in some common cases (e.g. for connectors
    // that generate only 1 task each; in a cluster of 2 or an even # of nodes, only even nodes will be assigned
    // connectors and only odd nodes will be assigned tasks, but tasks are, on average, actually more resource
    // intensive than connectors).
    List<String> connectorsSorted = sorted(coordinator.configSnapshot().connectors());
    CircularIterator<String> memberIt = new CircularIterator<>(sorted(memberConfigs.keySet()));
    for (String connectorId : connectorsSorted) {
        String connectorAssignedTo = memberIt.next();
        log.trace("Assigning connector {} to {}", connectorId, connectorAssignedTo);
        Collection<String> memberConnectors = connectorAssignments.computeIfAbsent(connectorAssignedTo, k -> new ArrayList<>());
        memberConnectors.add(connectorId);
    }
    for (String connectorId : connectorsSorted) {
        for (ConnectorTaskId taskId : sorted(coordinator.configSnapshot().tasks(connectorId))) {
            String taskAssignedTo = memberIt.next();
            log.trace("Assigning task {} to {}", taskId, taskAssignedTo);
            Collection<ConnectorTaskId> memberTasks = taskAssignments.computeIfAbsent(taskAssignedTo, k -> new ArrayList<>());
            memberTasks.add(taskId);
        }
    }
    coordinator.leaderState(new LeaderState(memberConfigs, connectorAssignments, taskAssignments));
    return fillAssignmentsAndSerialize(memberConfigs.keySet(), Assignment.NO_ERROR, leaderId, memberConfigs.get(leaderId).url(), maxOffset, connectorAssignments, taskAssignments);
}