java.util.NoSuchElementException: No value present when using ZooKeeperUpdatingListener

[liuzhengyang]

Hi, I am new to armeria. I build a simple project using armeria 0.5.60 according to armeria documentation, everything goes well until using 'Service discovery with ZooKeeper'. I got this exception

java.util.NoSuchElementException: No value present
	at java.util.Optional.get(Optional.java:135)
	at java.util.concurrent.CompletableFuture.reportJoin(CompletableFuture.java:375)
	at com.linecorp.armeria.server.zookeeper.ZooKeeperUpdatingListener.serverStarting(ZooKeeperUpdatingListener.java:69)
	at java.util.concurrent.CompletableFuture.join(CompletableFuture.java:1934)
	at com.linecorp.armeria.server.Server$StateManager.notifyState(Server.java:585)
	at com.github.liuzhengyang.server.Bootstrap.main(Bootstrap.java:38)
	at com.linecorp.armeria.server.Server$StateManager.enterStarting(Server.java:541)
Caused by: java.lang.IllegalStateException: failed to notify all server listeners
	at com.linecorp.armeria.server.Server.start(Server.java:250)
	at com.linecorp.armeria.server.Server$StateManager.enterStarting(Server.java:542)
	at com.linecorp.armeria.server.Server.start(Server.java:235)
	at com.linecorp.armeria.server.Server.start(Server.java:250)
	at com.github.liuzhengyang.server.Bootstrap.main(Bootstrap.java:38)
	at com.linecorp.armeria.server.Server.start(Server.java:235)
	... 1 more

And here is my example code.

public class Bootstrap {
    public static void main(String[] args) {

        ServerBuilder sb = new ServerBuilder();
        sb.port(8081, "http");

        sb.serviceUnder("/hello",
                        new GrpcServiceBuilder()
                                .addService(new MyHelloService())
                                .supportedSerializationFormats(GrpcSerializationFormats.values())
                                .enableUnframedRequests(true)
                                .build());
        sb.accessLogWriter(AccessLogWriters.common());

        sb.serviceUnder("/docs", new DocService());

        Server server = sb.build();

        ServerListener serverListener = new ZooKeeperUpdatingListener("localhost:2181", "/myProducionEndpoints", 1000);
        server.addListener(serverListener);

        server.start().join();
    }
}

If i remove the ServerListener, it works well. And i looked into com.linecorp.armeria.server.Server, found primaryActivePort is set in ServerPortStartListener, but ZooKeeperUpdatingListener.serverStarting is triggered before ServerPortStartListener added to Server start future listeners.

Did I miss something?
I am not sure whether I explained this problem clear or not. Thanks in advance.

[trustin]

Thanks for reporting! Let me take a look and get back to you soon.

[trustin]

Indeed. The access to the active ports should be done in serverStarted, not in serverStarting. Let me send a fix PR.