Refactor streaming to simplify for logging change (#28056)

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Emelia Smith 2023-11-28 15:24:41 +01:00 committed by GitHub
parent 4949b6da58
commit a4de0e364b
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3 changed files with 139 additions and 92 deletions

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@ -12,10 +12,12 @@ const { JSDOM } = require('jsdom');
const log = require('npmlog');
const pg = require('pg');
const dbUrlToConfig = require('pg-connection-string').parse;
const metrics = require('prom-client');
const uuid = require('uuid');
const WebSocket = require('ws');
const { setupMetrics } = require('./metrics');
const { isTruthy } = require("./utils");
const environment = process.env.NODE_ENV || 'development';
// Correctly detect and load .env or .env.production file based on environment:
@ -196,78 +198,15 @@ const startServer = async () => {
const redisClient = await createRedisClient(redisConfig);
const { redisPrefix } = redisConfig;
// Collect metrics from Node.js
metrics.collectDefaultMetrics();
new metrics.Gauge({
name: 'pg_pool_total_connections',
help: 'The total number of clients existing within the pool',
collect() {
this.set(pgPool.totalCount);
},
});
new metrics.Gauge({
name: 'pg_pool_idle_connections',
help: 'The number of clients which are not checked out but are currently idle in the pool',
collect() {
this.set(pgPool.idleCount);
},
});
new metrics.Gauge({
name: 'pg_pool_waiting_queries',
help: 'The number of queued requests waiting on a client when all clients are checked out',
collect() {
this.set(pgPool.waitingCount);
},
});
const connectedClients = new metrics.Gauge({
name: 'connected_clients',
help: 'The number of clients connected to the streaming server',
labelNames: ['type'],
});
const connectedChannels = new metrics.Gauge({
name: 'connected_channels',
help: 'The number of channels the streaming server is streaming to',
labelNames: [ 'type', 'channel' ]
});
const redisSubscriptions = new metrics.Gauge({
name: 'redis_subscriptions',
help: 'The number of Redis channels the streaming server is subscribed to',
});
const redisMessagesReceived = new metrics.Counter({
name: 'redis_messages_received_total',
help: 'The total number of messages the streaming server has received from redis subscriptions'
});
const messagesSent = new metrics.Counter({
name: 'messages_sent_total',
help: 'The total number of messages the streaming server sent to clients per connection type',
labelNames: [ 'type' ]
});
// Prime the gauges so we don't loose metrics between restarts:
redisSubscriptions.set(0);
connectedClients.set({ type: 'websocket' }, 0);
connectedClients.set({ type: 'eventsource' }, 0);
// For each channel, initialize the gauges at zero; There's only a finite set of channels available
CHANNEL_NAMES.forEach(( channel ) => {
connectedChannels.set({ type: 'websocket', channel }, 0);
connectedChannels.set({ type: 'eventsource', channel }, 0);
});
// Prime the counters so that we don't loose metrics between restarts.
// Unfortunately counters don't support the set() API, so instead I'm using
// inc(0) to achieve the same result.
redisMessagesReceived.inc(0);
messagesSent.inc({ type: 'websocket' }, 0);
messagesSent.inc({ type: 'eventsource' }, 0);
const metrics = setupMetrics(CHANNEL_NAMES, pgPool);
// TODO: migrate all metrics to metrics.X.method() instead of just X.method()
const {
connectedClients,
connectedChannels,
redisSubscriptions,
redisMessagesReceived,
messagesSent,
} = metrics;
// When checking metrics in the browser, the favicon is requested this
// prevents the request from falling through to the API Router, which would
@ -388,25 +327,6 @@ const startServer = async () => {
}
};
const FALSE_VALUES = [
false,
0,
'0',
'f',
'F',
'false',
'FALSE',
'off',
'OFF',
];
/**
* @param {any} value
* @returns {boolean}
*/
const isTruthy = value =>
value && !FALSE_VALUES.includes(value);
/**
* @param {any} req
* @param {any} res

105
streaming/metrics.js Normal file
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@ -0,0 +1,105 @@
// @ts-check
const metrics = require('prom-client');
/**
* @typedef StreamingMetrics
* @property {metrics.Registry} register
* @property {metrics.Gauge<"type">} connectedClients
* @property {metrics.Gauge<"type" | "channel">} connectedChannels
* @property {metrics.Gauge} redisSubscriptions
* @property {metrics.Counter} redisMessagesReceived
* @property {metrics.Counter<"type">} messagesSent
*/
/**
*
* @param {string[]} channels
* @param {import('pg').Pool} pgPool
* @returns {StreamingMetrics}
*/
function setupMetrics(channels, pgPool) {
// Collect metrics from Node.js
metrics.collectDefaultMetrics();
new metrics.Gauge({
name: 'pg_pool_total_connections',
help: 'The total number of clients existing within the pool',
collect() {
this.set(pgPool.totalCount);
},
});
new metrics.Gauge({
name: 'pg_pool_idle_connections',
help: 'The number of clients which are not checked out but are currently idle in the pool',
collect() {
this.set(pgPool.idleCount);
},
});
new metrics.Gauge({
name: 'pg_pool_waiting_queries',
help: 'The number of queued requests waiting on a client when all clients are checked out',
collect() {
this.set(pgPool.waitingCount);
},
});
const connectedClients = new metrics.Gauge({
name: 'connected_clients',
help: 'The number of clients connected to the streaming server',
labelNames: ['type'],
});
const connectedChannels = new metrics.Gauge({
name: 'connected_channels',
help: 'The number of channels the streaming server is streaming to',
labelNames: [ 'type', 'channel' ]
});
const redisSubscriptions = new metrics.Gauge({
name: 'redis_subscriptions',
help: 'The number of Redis channels the streaming server is subscribed to',
});
const redisMessagesReceived = new metrics.Counter({
name: 'redis_messages_received_total',
help: 'The total number of messages the streaming server has received from redis subscriptions'
});
const messagesSent = new metrics.Counter({
name: 'messages_sent_total',
help: 'The total number of messages the streaming server sent to clients per connection type',
labelNames: [ 'type' ]
});
// Prime the gauges so we don't loose metrics between restarts:
redisSubscriptions.set(0);
connectedClients.set({ type: 'websocket' }, 0);
connectedClients.set({ type: 'eventsource' }, 0);
// For each channel, initialize the gauges at zero; There's only a finite set of channels available
channels.forEach(( channel ) => {
connectedChannels.set({ type: 'websocket', channel }, 0);
connectedChannels.set({ type: 'eventsource', channel }, 0);
});
// Prime the counters so that we don't loose metrics between restarts.
// Unfortunately counters don't support the set() API, so instead I'm using
// inc(0) to achieve the same result.
redisMessagesReceived.inc(0);
messagesSent.inc({ type: 'websocket' }, 0);
messagesSent.inc({ type: 'eventsource' }, 0);
return {
register: metrics.register,
connectedClients,
connectedChannels,
redisSubscriptions,
redisMessagesReceived,
messagesSent,
};
}
exports.setupMetrics = setupMetrics;

22
streaming/utils.js Normal file
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@ -0,0 +1,22 @@
// @ts-check
const FALSE_VALUES = [
false,
0,
'0',
'f',
'F',
'false',
'FALSE',
'off',
'OFF',
];
/**
* @param {any} value
* @returns {boolean}
*/
const isTruthy = value =>
value && !FALSE_VALUES.includes(value);
exports.isTruthy = isTruthy;