1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
#!/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
// chance that a message will be taken into account for statistics (drops others for performance)
RELIABILITY = parseFloat(process.env.RELIABILITY) || 1.0;
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 });
const model = require("../orm/model")(seq, Seq);
logger.info("configuration", {
SCRIPT, QUEUE, BATCHSIZE, MAXCONNS, LOAD_TIMEOUT
});
// load update SQL scripts; scripts use sequelize replacements
// for the `participant_api_id` array
let script = fs.readFileSync(SCRIPT, "utf8");
// array of all consumable ids
const active_items = (await model.Item.findAll({
where: { is_activable: true }
})).map((i) => i.id);
// returns an SQL snippet like this:
/* sum(column_get(p_i.item_grants, '14')) as item_014_use
* or
* item_014_use = item_014_use + values(item_014_use)
*/
const dynamic_sql = (doCreate, tableName) => {
const pad = (i) => i.toString().padStart(3, "0");
if (doCreate) { // insert
return active_items.map((i) =>
`sum(column_get(${tableName}.item_uses, '${i}' as int)) ` +
`as item_${pad(i)}_use`
).join(",\n");
} else {
return active_items.map((i) =>
`item_${pad(i)}_use = item_${pad(i)}_use + values(item_${pad(i)}_use)`
).join(",\n");
}
};
// generate
const
p_i_item_uses_insert = dynamic_sql(true, 'p_i'),
p_i_item_uses_update = dynamic_sql(false, 'p_i'),
ph_item_uses_insert = dynamic_sql(true, 'ph'),
ph_item_uses_update = dynamic_sql(false, 'ph')
;
// replace stubs
Object.entries({
p_i_item_uses_insert,
p_i_item_uses_update,
ph_item_uses_insert,
ph_item_uses_update
}).forEach(([key, value]) => script = script.replace('_' + key, value));
// 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) => {
if (msg.content.length > 1024) {
// thx NodeJS for implementing `new Buffer(size)`
// Sometimes I fuck up during message sending
// and forget a `id.toString()`, creating huge blobs of zeros,
// which makes Sequelize panic because the packets are 2MB.
// May god forgive me for deploying debug code…
await ch.nack(msg, false, false);
return;
}
if (RELIABILITY < 1.0 && Math.random() > RELIABILITY) {
// randomly drop some data :)
await ch.nack(msg, false, false);
return;
}
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
await Promise.map(msgs, async (m) => {
if (m.properties.headers.notify)
await ch.publish("amq.topic",
m.properties.headers.notify,
new Buffer("crunch_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
});
|
