56 lines
1.5 KiB
Java
56 lines
1.5 KiB
Java
package jdocs.cluster;
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import static jdocs.cluster.TransformationMessages.BACKEND_REGISTRATION;
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import jdocs.cluster.TransformationMessages.TransformationJob;
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import jdocs.cluster.TransformationMessages.TransformationResult;
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import akka.actor.AbstractActor;
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import akka.cluster.Cluster;
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import akka.cluster.ClusterEvent.CurrentClusterState;
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import akka.cluster.ClusterEvent.MemberUp;
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import akka.cluster.Member;
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import akka.cluster.MemberStatus;
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//#backend
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public class TransformationBackend extends AbstractActor {
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Cluster cluster = Cluster.get(getContext().getSystem());
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//subscribe to cluster changes, MemberUp
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@Override
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public void preStart() {
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cluster.subscribe(getSelf(), MemberUp.class);
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}
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//re-subscribe when restart
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@Override
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public void postStop() {
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cluster.unsubscribe(getSelf());
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}
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@Override
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public Receive createReceive() {
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return receiveBuilder()
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.match(TransformationJob.class, job -> {
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getSender().tell(new TransformationResult(job.getText().toUpperCase()),
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getSelf());
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})
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.match(CurrentClusterState.class, state -> {
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for (Member member : state.getMembers()) {
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if (member.status().equals(MemberStatus.up())) {
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register(member);
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}
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}
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})
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.match(MemberUp.class, mUp -> {
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register(mUp.member());
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})
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.build();
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}
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void register(Member member) {
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if (member.hasRole("frontend"))
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getContext().actorSelection(member.address() + "/user/frontend").tell(
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BACKEND_REGISTRATION, getSelf());
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}
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}
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//#backend
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