Spectator-js
⚠️ Experimental
Simple library for instructing code to record dimentional time series.
Description
This implements a basic Spectator library for instrumenting nodejs applications, sending metrics to an Atlas aggregator service.
Instrumenting Code
'use strict';
const spectator = require('nflx-spectator');
// Netflix applications can use the nflx-spectator-config node module available
// internally through artifactory to generate the config required by nflx-spectator
function getConfig() {
return {
commonTags: {'nf.node': 'i-1234'},
uri: 'http://atlas.example.org/v1/publish',
timeout: 1000 // milliseconds
}
}
class Response {
constructor(status, size) {
this.status = status;
this.size = size;
}
}
class Server {
constructor(registry) {
this.registry = registry;
// create a base Id, to which we'll add some dynamic tags later
this.requestCountId = registry.createId('server.requestCount', {version: 'v1'});
this.requestLatency = registry.timer('server.requestLatency');
this.responseSize = registry.distributionSummary('server.responseSizes');
}
handle(request) {
const start = this.registry.hrtime();
// do some work based on request and obtain a response
const res = new Response(200, 64);
// update the counter id with dimensions based on the request. The
// counter will then be looked up in the registry which should be
// fairly cheap, such as a lookup of an id object in a map
// However, it is more expensive than having a local variable set
// to the counter
const counterId = this.requestCountId.withTags({country: request.country,
status: res.status});
this.registry.counter(counterId).increment();
this.requestLatency.record(this.registry.hrtime(start));
this.responseSize.record(res.size);
return res;
}
}
const config = getConfig();
const registry = new spectator.Registry(config);
class Request {
constructor(country) {
this.country = country;
}
}
// somehow get a request from the user...
function getNextRequest() {
return new Request('AR');
}
function handleTermination() {
registry.stop();
}
process.on('SIGINT', handleTermination);
process.on('SIGTERM', handleTermination);
registry.start();
const server = new Server(registry);
for (let i = 0; i < 3; ++i) {
const req = getNextRequest();
server.handle(req)
}
registry.stop();