HTTP/2 and What it Means for the Java EE Ecosystem

Others Talk, We Listen.

HTTP/2 and What it Means for the Java EE EcosystemReza RahmanSenior [email protected]@reza_rahman

CapTech

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Why HTTP/2?


The Web of the Past

Why HTTP/2?


The Web Today

HTTP Pipelining/Head-of-Line Blocking


style1.cssstyle2.css

Client Server

index.html

index.html

style1.cssstyle2.cssscript1.js

.

.

.

script2.js

.

.

.

script1.jsscript2.js

Socket Abuse/Max Connections


Client Server

Client Server

Client Server

Client Server

Client Server

Client Server

HTTP 1.1 Hacks

• File concatenation and image sprites• Domain sharding• Inlined assets


HTTP/2

• HTTP/2 is new transport layer underneath HTTP/1.1• Same request/response model• No new methods• No new headers• No new URLs or ports


At the Network Layer

HTTP/2

• Sockets scarce resource• Only one open per server


At the Socket Layer

Socket Abuse/Max Connections


Client Server

Client Server

Client Server

Client Server

Client Server

Client Server

Sockets in HTTP/2


Client Server

HTTP/2 Big Ticket Features

• Request/response multiplexing• Binary framing• Stream prioritization• Server push• Header compression• HTTP/2 upgrade

• ALPN• 101 Switching Protocols


HTTP/2 Request/Response Multiplexing


HTTP/2 Request/Response Multiplexing


HTTP/2 Header Compression


HTTP/2 Stream Prioritization


A

B C

4 12

A

B CD

4 16 12

A

B C

D

4 12

16

HTTP/2 Server Push

• Eliminates need for resource in-lining.• Lets server populate browser’s cache in advance.


HTTP/2 Upgrade from HTTP/1.1

• Not secure• Use port 80• Use existing 101 Switching Protocols from HTTP/1.1

• Secure• Application Layer Protocol Negotiation (ALPN)


http://www.http2demo.io


http://www.http2demo.io/

Servlet 4 Abstracts All This


Servlet 4

• Servlet well positioned to enable HTTP/2• Low-level protocol changes absorbed transparently• Allow frameworks to effectively leverage server push


Challenges Exposing HTTP/2 Features in Servlet

• Existing API designed for one request == one response.• HTTP/2 destroys this assumption.• It will be challenging to do justice to the new reality of one request == one or more responses.


HTTP/2 Features Exposed in Servlet

• Request/response multiplexing• Binary framing• Stream prioritization• Server push• Header compression• HTTP/2 upgrade

• ALPN• 101 Switching Protocols


Servlet 4 New Features

• HTTP/2 required• Server push

• Push resource to client for a given URL and headers.• Really useful for frameworks that build on Servlet, such as JSF• Builder API


javax.servlet.http.PushBuilder


Server Push via Builder API


Server Push in JSF


public class FacesServlet implements Servlet { public void service(ServletRequest req, ServletResponse resp) throws IOException, ServletException { //... HttpServletRequest request = (HttpServletRequest) req; try { ResourceHandler handler = context.getApplication().getResourceHandler(); if (handler.isResourceRequest(context)) { handler.handleResourceRequest(context); } else { lifecycle.attachWindow(context); lifecycle.execute(context); lifecycle.render(context); } } }

Server Push in JSF


public class ExternalContextImpl extends ExternalContext { //... public String encodeResourceURL(String url) { if (null == url) { String message = MessageUtils.getExceptionMessageString (MessageUtils.NULL_PARAMETERS_ERROR_MESSAGE_ID, "url"); throw new NullPointerException(message); } ((HttpServletRequest) request).getPushBuilder().path(url).push(); return ((HttpServletResponse) response).encodeURL(url); } //...}

Current Status


• Minimal early draft released, further progress basically stalled.

Java EE Guardians

https://groups.google.com/group/javaee-guardians@javaee_guardian


https://groups.google.com/group/javaee-guardians

Resources

• http2 explained• https://daniel.haxx.se/http2/

• Servlet 4 Specification• https://servlet-spec.java.net



Date post:	11-Jan-2017
Category:	Technology
Upload:	reza-rahman
View:	17,501 times
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HTTP/2 and What it Means for the Java EE Ecosystem

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