Class is not registered: io.atomix.cluster.MemberId

[eonie]

Expected behavior

Run leader election successful

Actual behavior

When run leader election, i got an error

Exception in thread "main" java.lang.IllegalArgumentException: Class is not registered: io.atomix.cluster.MemberId
Note: To register this class use: kryo.register(io.atomix.cluster.MemberId.class);
	at com.esotericsoftware.kryo.Kryo.getRegistration(Kryo.java:503)
	at com.esotericsoftware.kryo.util.DefaultClassResolver.writeClass(DefaultClassResolver.java:97)
	at com.esotericsoftware.kryo.Kryo.writeClass(Kryo.java:540)
	at com.esotericsoftware.kryo.Kryo.writeClassAndObject(Kryo.java:645)
	at io.atomix.utils.serializer.Namespace.lambda$null$0(Namespace.java:347)
	at com.esotericsoftware.kryo.pool.KryoPoolQueueImpl.run(KryoPoolQueueImpl.java:58)
	at io.atomix.utils.serializer.Namespace.lambda$serialize$1(Namespace.java:346)
	at io.atomix.utils.serializer.KryoIOPool.run(KryoIOPool.java:45)
	at io.atomix.utils.serializer.Namespace.serialize(Namespace.java:345)
	at io.atomix.utils.serializer.Namespace.serialize(Namespace.java:334)
	at io.atomix.utils.serializer.Serializer$1.encode(Serializer.java:71)
	at io.atomix.core.election.impl.DefaultLeaderElectionBuilder.lambda$null$1(DefaultLeaderElectionBuilder.java:44)
	at io.atomix.core.election.impl.TranscodingAsyncLeaderElection.run(TranscodingAsyncLeaderElection.java:52)
	at io.atomix.core.election.impl.BlockingLeaderElection.run(BlockingLeaderElection.java:49)
	at org.turnera.server.cluster.Server3.main(Server3.java:21)

Minimal yet complete reproducer code (or URL to code)

public class AotmixServer {
    public static CompletableFuture<Atomix> getServer(int port, Collection<Integer> ports) {
        String server = "server" + port;
        List<String> servers = ports.stream().map(p -> "server" + p).collect(Collectors.toList());

        AtomixBuilder builder = Atomix.builder();
        builder.withMemberId(server).withAddress("127.0.0.1", port)
                .withMembershipProvider(new BootstrapDiscoveryProvider(ports.stream()
                        .map(p -> Node.builder().withId("server" + p)
                                .withAddress(p).build())
                        .collect(Collectors.toList())))
                .withManagementGroup(RaftPartitionGroup.builder("system")
                        .withNumPartitions(1).withMembers(servers)
                        .withDataDirectory(new File("mngdir", server))
                        .withStorageLevel(StorageLevel.MEMORY).build())
                .addPartitionGroup(RaftPartitionGroup.builder("data")
                        .withNumPartitions(1).withMembers(servers)
                        .withDataDirectory(new File("datadir", server))
                        .withStorageLevel(StorageLevel.MEMORY).build());
        Atomix atomix = builder.build();

        atomix.getMembershipService().addListener(event -> System.out.println(event.toString()));

        System.out.println("trying to start " + server + " on port " + port + ".");
        return CompletableFuture.supplyAsync(() -> {
            atomix.start().join();
            return atomix;
        });
    }

}

public class Server1 {

    public static void main(String[] args) {
        List< Integer> ports = Arrays.asList(5002, 5003, 5004);
        int cur = 5002;
        Atomix atomix = AotmixServer.getServer(cur, ports).join();
        AtomicValue<String> value = atomix.getAtomicValue("value");
        // Get or create a leader election
        LeaderElection<MemberId> election = atomix.getLeaderElection("my-election");

        // Enter the election
        Leadership<MemberId> leadership = election.run(atomix.getMembershipService().getLocalMember().id());

        // Check if the current node is the leader
        if (leadership.leader().equals(atomix.getMembershipService().getLocalMember().id())) {
            System.out.println("I am the leader!");
        }

        // Listen for changes in leadership
        election.addListener(event -> {
            if (event.newLeadership().leader().equals(atomix.getMembershipService().getLocalMember().id())) {
                System.out.println("I am the leader!");
            }
        });
        System.out.println("done");
    }
}

Environment

• Atomix: [3.0.15]
• OS: [macOS 10.14.4 ]
• JVM [1.8.0_121]

[santhoshTpixler]

In Atomix: [3.1.5] the below code works. Not able to find the documentation. Anyway figured it out.

  Serializer s = Serializer.builder().withRegistrationRequired(false).build();

    LeaderElection<MemberId> election =
        atomix
            .<MemberId>leaderElectionBuilder("my-election")
            .withSerializer(s)
            .withProtocol(
                MultiRaftProtocol.builder()
                    .withReadConsistency(ReadConsistency.LINEARIZABLE)
                    .build())
            .build();

[franz1981]

@santhoshTpixler Thanks, I'm trying with the last version this same fix: but is a required step? I mean, on the doc I haven't found it to be necessary to get the election to work.

[johnou]

no shouldn't be required, it means the default serializer for the leaderelection code is missing MemberId, setting a custom serializer, especially with reg required false is a hacky work-around.

[johnou]

so after further investigation, I believe the correct fix for this, is to add a new "elementType" configuration to io.atomix.core.election.LeaderElectionConfig and io.atomix.core.election.LeaderElectorConfig then register that in DefaultLeaderElectionBuilder and DefaultLeaderElectorBuilder in a serializer override.

[johnou]

As a work around you might consider using string of the member id.