Node.js
???
Jack Wearden, @JackWeirdy
HELLO
What this talk isn't
- Node vs (Rails | PHP | Django)
- Ermagherd JavaScript
Node?
- JavaScript toolset built around V8
- Core libs (filesystem, network...)
- Simple module system
- Super-awesome package manager
- Node is just JavaScript
Node is all about asynchronous code
Node.js uses an event-driven, non-blocking I/O model
Popular new platform uses buzzwords... what's new?
We've been writing badly-scaling code
Consider:
echo("hello");
sleep(1);
echo("world");
Versus:
setTimeout(function() {
console.log("world");
}, 1000);
console.log("hello");
void main() {
s = new Socket("127.0.0.1", 80);
while(conn = s.accept()) {
in = conn.read();
/* STUFF */
conn.write("200 OK");
/* STUFF++ */
conn.close();
}
s.close()
}
void main() {
s = new Socket("127.0.0.1", 80);
conns = []
while(conn = s.accept()) {
conns.push(conn);
if (fork() == 0) {
in = conn.read();
/* STUFF */
conn.write("200 OK");
/* STUFF++ */
conns.remove(conn);
conn.close();
}
}
s.close();
}code++
code++
code++
In reality apache pre-forks & maintains a pool
The premise is the same: 1 process per request (by default)
Teeny node webserver
var http = require("http");
http.createServer(function(request, response) {
response.writeHead(200, {"Content-Type": "text/plain"});
response.end("response body");
}).listen(8765);
We map events to behaviour
Event checking is delegated to Node
Event handling is implemented in JS
Our code is only called when something has to be done
Potentially more testable?
Async is increasingly important
Doing more with 1 thread
More with 1 thread = more with 1 core
More with 1 core = linear scaling to 4, 8, 32 and beyond
Demo time!
[Questions so far?]
