Examples with EvenScheduler backtype.storm.scheduler.EvenScheduler used on opensource projects

Example 1 with EvenScheduler

use of backtype.storm.scheduler.EvenScheduler in project storm-lib by xumingming.

the class DemoScheduler method schedule.

public void schedule(Topologies topologies, Cluster cluster) {
    System.out.println("DemoScheduler: begin scheduling");
    // Gets the topology which we want to schedule
    TopologyDetails topology = topologies.getByName("special-topology");
    // make sure the special topology is submitted,
    if (topology != null) {
        boolean needsScheduling = cluster.needsScheduling(topology);
        if (!needsScheduling) {
            System.out.println("Our special topology DOES NOT NEED scheduling.");
        } else {
            System.out.println("Our special topology needs scheduling.");
            // find out all the needs-scheduling components of this topology
            Map<String, List<ExecutorDetails>> componentToExecutors = cluster.getNeedsSchedulingComponentToExecutors(topology);
            System.out.println("needs scheduling(component->executor): " + componentToExecutors);
            System.out.println("needs scheduling(executor->compoenents): " + cluster.getNeedsSchedulingExecutorToComponents(topology));
            SchedulerAssignment currentAssignment = cluster.getAssignmentById(topologies.getByName("special-topology").getId());
            if (currentAssignment != null) {
                System.out.println("current assignments: " + currentAssignment.getExecutorToSlot());
            } else {
                System.out.println("current assignments: {}");
            }
            if (!componentToExecutors.containsKey("special-spout")) {
                System.out.println("Our special-spout DOES NOT NEED scheduling.");
            } else {
                System.out.println("Our special-spout needs scheduling.");
                List<ExecutorDetails> executors = componentToExecutors.get("special-spout");
                // find out the our "special-supervisor" from the supervisor metadata
                Collection<SupervisorDetails> supervisors = cluster.getSupervisors().values();
                SupervisorDetails specialSupervisor = null;
                for (SupervisorDetails supervisor : supervisors) {
                    Map meta = (Map) supervisor.getSchedulerMeta();
                    if (meta.get("name").equals("special-supervisor")) {
                        specialSupervisor = supervisor;
                        break;
                    }
                }
                // found the special supervisor
                if (specialSupervisor != null) {
                    System.out.println("Found the special-supervisor");
                    List<WorkerSlot> availableSlots = cluster.getAvailableSlots(specialSupervisor);
                    // TODO for simplicity, we free all the used slots on the supervisor.
                    if (availableSlots.isEmpty() && !executors.isEmpty()) {
                        for (Integer port : cluster.getUsedPorts(specialSupervisor)) {
                            cluster.freeSlot(new WorkerSlot(specialSupervisor.getId(), port));
                        }
                    }
                    // re-get the aviableSlots
                    availableSlots = cluster.getAvailableSlots(specialSupervisor);
                    // since it is just a demo, to keep things simple, we assign all the
                    // executors into one slot.
                    cluster.assign(availableSlots.get(0), topology.getId(), executors);
                    System.out.println("We assigned executors:" + executors + " to slot: [" + availableSlots.get(0).getNodeId() + ", " + availableSlots.get(0).getPort() + "]");
                } else {
                    System.out.println("There is no supervisor named special-supervisor!!!");
                }
            }
        }
    }
    // let system's even scheduler handle the rest scheduling work
    // you can also use your own other scheduler here, this is what
    // makes storm's scheduler composable.
    new EvenScheduler().schedule(topologies, cluster);
}