Examples with BalancedAssignmentStrategy co.cask.cdap.common.zookeeper.coordination.BalancedAssignmentStrategy used on opensource projects

Example 1 with BalancedAssignmentStrategy

use of co.cask.cdap.common.zookeeper.coordination.BalancedAssignmentStrategy in project cdap by caskdata.

the class DistributedStreamService method performLeaderElection.

/**
   * Elect one leader among the {@link DistributedStreamService}s running in different Twill runnables.
   */
private void performLeaderElection() {
    // Start the resource coordinator that will map Streams to Stream handlers
    leaderElection = new LeaderElection(// TODO: Should unify this leader election with DistributedStreamFileJanitorService
    zkClient, "/election/" + STREAMS_COORDINATOR, new ElectionHandler() {

        @Override
        public void leader() {
            LOG.info("Became Stream handler leader. Starting resource coordinator.");
            resourceCoordinator = new ResourceCoordinator(getCoordinatorZKClient(), discoveryServiceClient, new BalancedAssignmentStrategy());
            resourceCoordinator.startAndWait();
            updateRequirement();
        }

        @Override
        public void follower() {
            LOG.info("Became Stream handler follower.");
            if (resourceCoordinator != null) {
                resourceCoordinator.stopAndWait();
            }
        }
    });
    leaderElection.start();
}