Servlet 4 and HTTP2 - Githubissues

decebals commented 5 years ago

The idea is to play with Servlet 4 and see how we can add support for HTTP2 in Pippo.

decebals commented 5 years ago

It's related with #487. Actually, #487 is a subtask/subset of this issue.

decebals commented 5 years ago

Good news. I have a POC (a demo) for HTTP/2 in Pippo. Before to present you the code I will give you some information:

the demo use Jetty server (but this aspect is not so important because when the feature will be available, Tomcat and Undertow will support also this feature)
the demo present you how to use HTTP/2 server PUSH
the demo is tiny (only a route that serve a dynamic html page using template page)
HTTP/2 protocol will be enabled by default if you supply a keystore file (SSL)

So, now I can show the code and some pictures:

HTTP 1.1
HTTP/2 (H2)
HTTP/2 with PUSH

The important columns (right table) are:

Protocol
Initiator

Code:

application.properties

# SSL configuration
server.keystoreFile = keystore.jks
server.keystorePassword = password
server.truststoreFile = truststore.jks
server.truststorePassword = password

Http2Application

I posted the code on gist to have a lite comment here. In that code you can see that I implemented one of my idea, to extract automatically the assets/resources needed by the html page that will be send as response to the client. For extraction I used a HTML parser. Sure we can avoid this new dependency, because we don't need a full html parser. We can write a small class that can extract only the information needed for push. My final idea is to abstract all push mechanism in Response class. A simple push enabled flag/method in Response class from Pippo will be enough to push out of the box (automatically) all the assets of the page.

On my test branch I switched Pippo from Servlet 3.x to Servlet 4 to use the new features. The process was painless. Unfortunately the last Jetty version (9.4) doesn't implement Servlet 4 specification and from this reason I used in my demo the Jetty specific API. For the servers that implement already Servlet 4 specs, we will use javax.servlet.http.PushBuilder returned by HttpServletRequest#newPushBuilder method.

In the end, I can say that the code looks simple enough and it was a pleasure to work on/with this feature.

Any feedback is welcome.

decebals commented 5 years ago

To switch my HTTP/2 demo from Jetty to Undertow, all I made is to upgrade Undertow to the last version (2.0.17.Final). I remember you that I updated Servlet version to 4.0 in pippo-core, so we can use the javax.servlet.http.PushBuilder:

HttpServletRequest httpServletRequest = routeContext.getRequest().getHttpServletRequest();
PushBuilder pushBuilder = httpServletRequest.newPushBuilder();
getPushResourcePaths(html).forEach(path -> pushBuilder.path(path).push());

decebals commented 5 years ago

On Tomcat I encounter some problem. After I made some modifications in TomcatServer to enable HTTP/2:

private void enableSSLConnector(Tomcat tomcat) {
    // actual code

    // enable HTTP/2
    connector.setAttribute("sslImplementationName", "org.apache.tomcat.util.net.openssl.OpenSSLImplementation");
//    connector.setAttribute("sslImplementationName", "org.apache.tomcat.util.net.jse.JSSEImplementation");
    connector.addUpgradeProtocol(new Http2Protocol());
}

To go with OpenSSLImplementation you must install APR and Tomcat Native on your computer. On my dev machine I use Ubuntu 18.10 I installed all these dependencies via apt-get.

decebal@decebal:/usr/lib$ ldd libtcnative-1.so.0.2.17 
    linux-vdso.so.1 (0x00007ffd61da7000)
    libssl.so.1.1 => /usr/lib/x86_64-linux-gnu/libssl.so.1.1 (0x00007f2f2c9d9000)
    libcrypto.so.1.1 => /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1 (0x00007f2f2c70e000)
    libapr-1.so.0 => /usr/lib/x86_64-linux-gnu/libapr-1.so.0 (0x00007f2f2c6d6000)
    libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f2f2c6b5000)
    libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f2f2c4cb000)
    libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f2f2c4c5000)
    libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007f2f2c4ba000)
    /lib64/ld-linux-x86-64.so.2 (0x00007f2f2ccb9000)

When I run demo I obtain the below error message:

22:11:43 [main] INFO ro.pippo.tomcat.TomcatServer - Starting Tomcat Server 9.0.10 on port 8338
Jan 26, 2019 10:11:44 PM org.apache.coyote.http11.AbstractHttp11Protocol configureUpgradeProtocol
INFO: The ["https-openssl-nio-8338"] connector has been configured to support negotiation to [h2] via ALPN
Jan 26, 2019 10:11:44 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["https-openssl-nio-8338"]
Jan 26, 2019 10:11:44 PM org.apache.catalina.util.LifecycleBase handleSubClassException
SEVERE: Failed to initialize component [Connector[HTTP/1.1-8338]]
java.lang.UnsatisfiedLinkError: org.apache.tomcat.jni.Pool.create(J)J
    at org.apache.tomcat.jni.Pool.create(Native Method)
    at org.apache.tomcat.util.net.openssl.OpenSSLEngine.<clinit>(OpenSSLEngine.java:70)
    at org.apache.tomcat.util.net.openssl.OpenSSLUtil.getImplementedProtocols(OpenSSLUtil.java:61)
    at org.apache.tomcat.util.net.SSLUtilBase.<init>(SSLUtilBase.java:53)
    at org.apache.tomcat.util.net.openssl.OpenSSLUtil.<init>(OpenSSLUtil.java:41)
    at org.apache.tomcat.util.net.openssl.OpenSSLImplementation.getSSLUtil(OpenSSLImplementation.java:36)

Maybe someone who uses Tomcat and who has more experience like me with Tomcat can help.

whyicantusemyemailasusername commented 5 years ago

http2 on undertow works out of the box

decebals commented 5 years ago

http2 on undertow works out of the box

Yes. I said the same thing in https://github.com/pippo-java/pippo/issues/490#issuecomment-457213332.

pippo-java / pippo

Servlet 4 and HTTP2 #490