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#!/usr/bin/node
/* jshint esnext:true */
"use strict";
/*
* cruncher calculates global_point and player_point for stats.
* It listens to the queue `crunch` and expects a JSON with
* a string that is a `participant.api_id`.
* cruncher will update the sums of points
* and send a notification to web.
*/
const amqp = require("amqplib"),
Promise = require("bluebird"),
fs = Promise.promisifyAll(require("fs")),
winston = require("winston"),
loggly = require("winston-loggly-bulk"),
sleep = require("sleep-promise"),
Seq = require("sequelize");
const RABBITMQ_URI = process.env.RABBITMQ_URI,
DATABASE_URI = process.env.DATABASE_URI,
QUEUE = process.env.QUEUE || "crunch",
SCRIPT = process.env.SCRIPT || "crunch_global.sql",
LOGGLY_TOKEN = process.env.LOGGLY_TOKEN,
// size of connection pool
MAXCONNS = parseInt(process.env.MAXCONNS) || 3,
// number of participants to calculate at once
BATCHSIZE = parseInt(process.env.BATCHSIZE) || 1000,
LOAD_TIMEOUT = parseInt(process.env.LOAD_TIMEOUT) || 5, // s
// wait time before next batch
SLOWMODE = parseFloat(process.env.SLOWMODE) || 0; // s
const logger = new (winston.Logger)({
transports: [
new (winston.transports.Console)({
timestamp: true,
colorize: true
})
]
});
// loggly integration
if (LOGGLY_TOKEN)
logger.add(winston.transports.Loggly, {
inputToken: LOGGLY_TOKEN,
subdomain: "kvahuja",
tags: ["backend", "cruncher", QUEUE],
json: true
});
amqp.connect(RABBITMQ_URI).then(async (rabbit) => {
// connect to rabbit & db
const seq = new Seq(DATABASE_URI, {
logging: false,
max: MAXCONNS
});
process.once("SIGINT", rabbit.close.bind(rabbit));
const ch = await rabbit.createChannel();
await ch.assertQueue(QUEUE, { durable: true });
await ch.assertQueue(QUEUE + "_failed", { durable: true });
// load update SQL scripts; scripts use sequelize replacements
// for the `participant_api_id` array
const script = fs.readFileSync(SCRIPT, "utf8");
// fill a buffer and execute an SQL on a bigger (> 1o) batch
const participants = new Set(),
// store the msgs that should be ACKed
buffer = new Set();
let timeout = undefined;
// set maximum allowed number of unacked msgs
await ch.prefetch(BATCHSIZE);
ch.consume(QUEUE, async (msg) => {
participants.add(msg.content.toString());
buffer.add(msg);
if (timeout == undefined) timeout = setTimeout(tryCrunch, LOAD_TIMEOUT*1000);
if (buffer.size >= BATCHSIZE) await tryCrunch();
}, { noAck: false });
// wrap crunch() in message handler
async function tryCrunch() {
const msgs = new Set(buffer),
api_ids = [...participants];
buffer.clear();
clearTimeout(timeout);
timeout = undefined;
participants.clear();
if (SLOWMODE > 0) {
logger.info("slowmode active, sleeping…", { wait: SLOWMODE });
await sleep(SLOWMODE * 1000);
}
try {
await crunch(api_ids);
} catch (err) {
// log, move to failed queue, NACK
logger.error(err);
await Promise.map(msgs, async (m) => {
await ch.sendToQueue(QUEUE + "_failed", m.content, {
persistent: true,
headers: m.properties.headers
});
await ch.nack(m, false, false);
});
return;
}
await Promise.map(msgs, async (m) => await ch.ack(m));
// notify web
// TODO notify for player too
// TODO fix these
await ch.publish("amq.topic", "global", new Buffer("points_update"));
}
// execute the script
async function crunch(api_ids) {
const profiler = logger.startTimer();
logger.info("crunching", { size: api_ids.length });
await seq.query(script, {
replacements: {
build_regex_start: '^([[:digit:]]+;[[:digit:]]+,)*(',
build_regex_end: ')+(,[[:digit:]]+;[[:digit:]]+)*$',
participant_api_ids: api_ids
},
type: seq.QueryTypes.UPSERT
});
profiler.done("crunched", { size: api_ids.length });
}
});
process.on("unhandledRejection", (err) => {
logger.error(err);
process.exit(1); // fail hard and die
});
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