SessionImpl class is not serializable so fails in clustered session store.

[mark-ennis]

The SessionImpl class is not serializable because is lacks a zero argument constructor. This means that it causes an exception when using sessions with a ClusteredSessionStore. The serialised form created by the writeToBuffer() method does not include the "timeout" field (which results in sessions being discarded as soon as they are referenced from the store) or the "id" field which appears to be needed, although, I did not identify exactly where. I have updated the SessionImpl class to overcome these problems.

[purplefox]

Hi Mark - is this still an issue?

I will close this for now, if it is, please re-open :)

[mark-ennis]

Yes, it is still an issue.

Apr 15, 2015 8:28:15 AM io.vertx.ext.apex.impl.RoutingContextImplBase
SEVERE: Unexpected exception in route
com.hazelcast.nio.serialization.HazelcastSerializationException: Problem while reading DataSerializable, namespace: 0, id: 0, class: 'io.vertx.spi.cluster.impl.hazelcast.HazelcastAsyncMap$DataSerializableHolder', exception: Failed to load class io.vertx.ext.apex.sstore.impl.SessionImpl
at com.hazelcast.nio.serialization.DataSerializer.read(DataSerializer.java:120)
at com.hazelcast.nio.serialization.DataSerializer.read(DataSerializer.java:39)
at com.hazelcast.nio.serialization.StreamSerializerAdapter.toObject(StreamSerializerAdapter.java:65)
at com.hazelcast.nio.serialization.SerializationServiceImpl.toObject(SerializationServiceImpl.java:260)
at com.hazelcast.spi.impl.NodeEngineImpl.toObject(NodeEngineImpl.java:186)
at com.hazelcast.map.impl.AbstractMapServiceContextSupport.toObject(AbstractMapServiceContextSupport.java:42)
at com.hazelcast.map.impl.DefaultMapServiceContext.toObject(DefaultMapServiceContext.java:28)
at com.hazelcast.map.impl.proxy.MapProxySupport.toObject(MapProxySupport.java:1038)
at com.hazelcast.map.impl.proxy.MapProxyImpl.get(MapProxyImpl.java:84)
at io.vertx.spi.cluster.impl.hazelcast.HazelcastAsyncMap.lambda$get$0(HazelcastAsyncMap.java:46)
at io.vertx.spi.cluster.impl.hazelcast.HazelcastAsyncMap$$Lambda$126/463866392.handle(Unknown Source)
at io.vertx.core.impl.ContextImpl.lambda$executeBlocking$2(ContextImpl.java:219)
at io.vertx.core.impl.ContextImpl$$Lambda$6/917831210.run(Unknown Source)
at io.vertx.core.impl.OrderedExecutorFactory$OrderedExecutor.lambda$new$180(OrderedExecutorFactory.java:91)
at io.vertx.core.impl.OrderedExecutorFactory$OrderedExecutor$$Lambda$5/73181251.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.IllegalStateException: Failed to load class io.vertx.ext.apex.sstore.impl.SessionImpl
at io.vertx.spi.cluster.impl.hazelcast.HazelcastAsyncMap$DataSerializableHolder.readData(HazelcastAsyncMap.java:176)
at com.hazelcast.nio.serialization.DataSerializer.read(DataSerializer.java:111)
... 17 more
Caused by: java.lang.InstantiationException: io.vertx.ext.apex.sstore.impl.SessionImpl
at java.lang.Class.newInstance(Class.java:423)
at io.vertx.spi.cluster.impl.hazelcast.HazelcastAsyncMap$DataSerializableHolder.readData(HazelcastAsyncMap.java:173)
... 18 more
Caused by: java.lang.NoSuchMethodException: io.vertx.ext.apex.sstore.impl.SessionImpl.()
at java.lang.Class.getConstructor0(Class.java:3074)
at java.lang.Class.newInstance(Class.java:408)
... 19 more

[purplefox]

Do you have a reproducer for this?

[mark-ennis]

package com.viewds.test.vertx.cluster;

import io.vertx.core.AsyncResult;
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.core.http.HttpServer;
import io.vertx.core.logging.Logger;
import io.vertx.core.logging.impl.LoggerFactory;
import io.vertx.ext.apex.Router;
import io.vertx.ext.apex.RoutingContext;
import io.vertx.ext.apex.handler.CookieHandler;
import io.vertx.ext.apex.handler.SessionHandler;
import io.vertx.ext.apex.sstore.ClusteredSessionStore;
import io.vertx.ext.apex.sstore.SessionStore;

public class Example
implements Runnable
{
private static final Logger logger =
LoggerFactory.getLogger(Example.class);
private Vertx vertx;

public static void main(String[] args)
{
    new Example(args).run();
}

public Example(String[] args)
{
}

@Override
public void run()
{
    VertxOptions options;

    options = new VertxOptions();
    Vertx.clusteredVertx(options, (AsyncResult<Vertx> event) -> {
        if (event.succeeded()) {
            vertx = event.result();
            startHttpServer();
        }
        else {
            logger.error("failed to obtain vertx object", event.cause());
        }
    });
}

private void startHttpServer()
{
    SessionStore store;
    Router router;

    store = ClusteredSessionStore.create(vertx);

    router = Router.router(vertx);
    router.route().handler(CookieHandler.create());
    router.route().handler(SessionHandler.create(store));
    router.route().handler(this::doSomething);

    vertx.createHttpServer()
            .requestHandler(router::accept)
            .listen(8080, (AsyncResult<HttpServer> event) -> {
                if (event.succeeded()) {
                    logger.info("HTTP server started successfully");
                }
                else {
                    logger.error("HTTP server failed to start",
                            event.cause());
                }
            });
}

private void doSomething(RoutingContext context)
{
    Integer count;

    if ((count = context.session().get("count")) == null) {
        count = 0;
    }
    count += 1;
    context.session().put("count", count);
    context.response()
            .setStatusCode(200)
            .putHeader("Content-type", "text/plain")
            .end("count = " + count + "\n");
}

}

[mark-ennis]

I have put the above code in GitHub. See https://github.com/mark-ennis/vertx-example/tree/master/cluster.

[purplefox]

Thanks Mark, this should be fixed now (PR waiting for review).

The problem here was, although we have clustered session tests, they were all using the fake cluster manager which doesn't actually serialize the sessions.

[mark-ennis]

Great, thanks.