[Tomcat 9.0.31] Missing WebSocket ServerContainer

[boris-petrov]

After updating Tomcat from 9.0.30 to 9.0.31 our integration tests don't want to even start due to:

FAILED org.cometd.server.BayeuxServerImpl@1ec3f0e5: java.lang.IllegalArgumentException: Missing WebSocket ServerContainer
java.lang.IllegalArgumentException: Missing WebSocket ServerContainer
        at org.cometd.websocket.server.WebSocketTransport.init(WebSocketTransport.java:72)
        at org.cometd.server.BayeuxServerImpl.initializeServerTransports(BayeuxServerImpl.java:255)
        at org.cometd.server.BayeuxServerImpl.doStart(BayeuxServerImpl.java:135)
        at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
        at org.cometd.server.CometDServlet.init(CometDServlet.java:64)
        at org.cometd.annotation.AnnotationCometDServlet.init(AnnotationCometDServlet.java:52)
        at javax.servlet.GenericServlet.init(GenericServlet.java:158)
        at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1134)
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1089)
        at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:983)
        at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4871)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5180)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
        at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140)
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:841)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1384)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1374)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
        at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140)
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:909)
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:421)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.startup.Tomcat.start(Tomcat.java:467)
        ...

I'm not sure whether this is a Tomcat issue or a CometD one or I'm doing something wrong but it was working before... how do I begin debugging this? I have these dependencies (among others):

integrationTestRuntimeOnly "org.apache.tomcat.embed:tomcat-embed-websocket:$tomcatVersion"
integrationTestRuntimeOnly "org.cometd.java:cometd-java-server:$cometDVersion"
integrationTestRuntimeOnly "org.cometd.java:cometd-java-websocket-javax-server:$cometDVersion"

CometD version is 3.1.12.

[sbordet]

@boris-petrov the place where this exception is thrown is here.

This is the JSR 356 standard way to obtain the WebSocket ServerContainer, so Tomcat must expose it as per specification.

I don't know why it was working before, but this code in CometD did not change because it's the standard and only way of accessing the WebSocket container.

Have you asked the Tomcat project?

[boris-petrov]

@sbordet - I haven't asked there yet, no. So this cannot be an application-configuration issue but is rather a Tomcat problem for sure? Or it's possible I'm not doing something right?

[sbordet]

@boris-petrov I don't know. I don't think it's a CometD issue.

Could be your application configuration, or how you configure Tomcat, or how you package your webapp.

If it was Jetty, I would say that you have either misconfigured your JETTY_BASE if you use Jetty standalone server, or you have forgot some jar in the classpath if you use Jetty embedded.

Try to enable DEBUG logging for Tomcat, and you should see if there are errors.

[boris-petrov]

@sbordet - I've opened an issue in Tomcat's Bugzilla and I've given them a reproduction project so I hope they can fix it. I'll close this issue for now and will follow up if they think the problem is not there but in CometD.

Thanks for the support!

[sbordet]

@boris-petrov are you configuring Tomcat with HTTP/2 only (no HTTP/1.1) and WebSocket?
Chances are that Tomcat does not support WebSocket over HTTP/2 and so it won't expose the ServerContainer.

[boris-petrov]

Well, I do have this line:

tomcat.connector.add_upgrade_protocol(Http2Protocol.new)

But even commenting it out doesn't help. Also, I didn't change any code between the Tomcat version update so this was working before. I think this code doesn't remove the default HTTP/1.1 connector. Thanks for the suggestion!