#AMQP-RPC
RPC library based on AMQP protocol. Tested with RabbitMQ on the highload project.
###Install RabitMQ
apt-get install rabbitmq-server
###Install library
npm install amqp-rpc
##round-robin
Example: Call remote function. Run multiple servers.js for round-robin shared.
###server.js example
var rpc = require('amqp-rpc').factory({
exchange: "uuu-test", exchange_options: {exclusive: false, autoDelete: true},
conn_options: {url: "amqp://guest:guest@rabbitmq:5672", heartbeat: 10}
});
rpc.on('inc', function(param, cb){
var prevVal = param;
var nextVal = param+2;
cb(++param, prevVal, nextVal);
});
rpc.on('say.*', function(param, cb, inf){
var arr = inf.cmd.split('.');
var name = (param && param.name) ? param.name : 'world';
cb(arr[1] + ' ' + name + '!');
});
rpc.on('withoutCB', function(param, cb, inf) {
if(cb){
cb('please run function without cb parameter')
}
else{
console.log('this is function withoutCB');
}
});
###client.js example
var rpc = require('amqp-rpc').factory({
exchange: "uuu-test", exchange_options: {exclusive: false, autoDelete: true},
conn_options: {url: "amqp://guest:guest@rabbitmq:5672", heartbeat: 10}
});
rpc.call('inc', 5, function() {
console.log('results of inc:', arguments); //output: [6,4,7]
});
rpc.call('say.Hello', { name: 'John' }, function(msg) {
console.log('results of say.Hello:', msg); //output: Hello John!
});
rpc.call('withoutCB', {}, function(msg) {
console.log('withoutCB results:', msg); //output: please run function without cb parameter
});
rpc.call('withoutCB', {}); //output message on server side console
##broadcast
Example: Core receiving data from all workers. Run multiple worker.js for broadcast witness. The core.js must be launched after all worker.js instances.
###example/broadcast/worker.js
var os = require('os');
var worker_name = os.hostname() + ':' + process.pid;
var counter = 0;
var rpc = require('../../index').factory({
url: "amqp://guest:guest@localhost:5672"
});
rpc.onBroadcast('getWorkerStat', function(params, cb) {
if(params && params.type == 'fullStat') {
cb(null, {
pid: process.pid,
hostname: os.hostname(),
uptime: process.uptime(),
counter: counter++
});
}
else {
cb(null, { counter: counter++ })
}
});
###example/broadcast/core.js
var rpc = require('../../index').factory({
url: "amqp://guest:guest@localhost:5672"
});
var all_stats = {};
//rpc.callBroadcast() is rpc.call() + waiting multiple responses
//If remote handler without response data, you can use rpc.call() for initiate broadcast calls.
rpc.callBroadcast(
'getWorkerStat',
{ type: 'fullStat'}, //request parameters
{ //call options
ttl: 1000, //wait response time (1 seconds), after run onComplete
onResponse: function(err, stat) { //callback on each worker response
all_stats[ stat.hostname+':'+ stat.pid ] = stat;
},
onComplete: function() { //callback on ttl expired
console.log('----------------------- WORKER STATISTICS ----------------------------------------');
for(var worker in all_stats) {
s = all_stats[worker];
console.log(worker, '\tuptime=', s.uptime.toFixed(2) + ' seconds', '\tcounter=', s.counter);
}
}
});
Results for three workers:
----------------------- WORKER STATISTICS ----------------------------------------
host1:2612 uptime= 2470.39 seconds counter= 2
host2:1615 uptime= 3723.53 seconds counter= 8
host2:2822 uptime= 2279.16 seconds counter= 3
Eugene Demchenko aka Goldy skype demchenkoe email demchenkoev@gmail.com
0.2.4:
* bugfix memory leak
0.2.3:
* support for other exchanges than rpc_exchange
0.2.2:
* print channels fn