HTTP/2 support in Tomcat 8

Question

After some research, I was surprised that I did not not find any resource on HTTP/2 support in Tomcat. Changelogs of 8.0 indicate an experimental support of SPDY and wiki refers to HTTP/2 as a supported spec (http://wiki.apache.org/tomcat/Specifications) but I don't find any tutorial on it.

Do you know if it is already possible to enable HTTP/2 on Tomcat? If the answer is yes how I can do that?

Starch

Is there a question here? Ideas about what? I hope you are no asking where to find documentation ... because that is off-topic!! – Deirdra

I added the question explicitely... – Starch

possible duplicate of Configure SPDY on tomcat 8 windows – Deirdra

Short answer: don't bother. – Deirdra

See also: #30855781 – Client

Answer 1

Tomcat does not yet support HTTP/2.

HTTP/2 support is planned for Tomcat 9 onwards. It may get back-ported to earlier versions.

The experimental SPDY support was just that: experimental. It worked while the browsers supported the particular version of SPDY but no browser currently supports the version of SDPY implemented by Tomcat.

That experimental support of SPDY has been removed from Tomcat 8.0.22, noted in the changelog.

Dote

Answer 2

Tomcat 8.5 has been released with features back-ported from Tomcat 9 and includes HTTP/2 support.

I haven't personally had the chance to setup HTTP/2 on Tomcat 8.5 yet, so I can't comment on the "how to".

Rina

Answer 3

HTTP/2 Support is now available in Tomcat. Tomcat-8.5 supports HTTP/2. To enable HTTP/2 in tomcat-8.5 or above you need to upgrade the connector protocol in the file server.xml in the tomcat conf folder.

<Connector ... >
  <UpgradeProtocol className="org.apache.coyote.http2.Http2Protocol" />
</Connector>

You also need to set up the configuration of your SSL certificates to work with this connector.

Cherenkov

Thanks! How do you perform server-push? – Starch

Server Push can be performed using PushBuilder API in Java. – Cherenkov

So does it means that there is no native API that can be used and consequently servlet 4 is required? Also if this statement is true we can take advantage from server-push only in tomcat 9 because it seems that tomcat 8.5 still use servlet 3.1? – Starch

To add to the answer about configuring Tomcat 9 for HTTP/2 see this: readlearncode.com/configure-tomcat-9-for-http2 – Frank

HTTP/2 by default is made secure by design. Hence, we need to have SSL with HTTP2. If you do not want to have SSL, then you need to go back to HTTP 1.1 and cannot use HTTP2. – Cherenkov

Answer 4

to enable http2 for tomcat8.5.x,

@Bean
       public EmbeddedServletContainerCustomizer tomcatCustomizer() {
        return container -> {
            if (container instanceof TomcatEmbeddedServletContainerFactory) {
                ((TomcatEmbeddedServletContainerFactory) container).addConnectorCustomizers((connector) -> {
                    connector.addUpgradeProtocol(new Http2Protocol());
                });
            }
        };
    }

Requite