refactor(server): standarderlize metrics and trace with OTEL (#5054)

you can now export span to Zipkin and metrics to Prometheus when developing locally
follow the docs of OTEL: https://opentelemetry.io/docs/instrumentation/js/exporters/

<img width="2357" alt="image" src="https://github.com/toeverything/AFFiNE/assets/8281226/ec615e1f-3e91-43f7-9111-d7d2629e9679">

packages/backend/server/tests/auth.spec.ts

@@ -5,7 +5,6 @@ import test from 'ava';
 
 import { ConfigModule } from '../src/config';
 import { GqlModule } from '../src/graphql.module';
-import { MetricsModule } from '../src/metrics';
 import { AuthModule } from '../src/modules/auth';
 import { AuthResolver } from '../src/modules/auth/resolver';
 import { AuthService } from '../src/modules/auth/service';
@@ -40,7 +39,6 @@ test.beforeEach(async () => {
       PrismaModule,
       GqlModule,
       AuthModule,
-      MetricsModule,
       RateLimiterModule,
     ],
   }).compile();

packages/backend/server/tests/doc.spec.ts

@@ -10,7 +10,6 @@ import { Doc as YDoc, encodeStateAsUpdate } from 'yjs';
 
 import { CacheModule } from '../src/cache';
 import { Config, ConfigModule } from '../src/config';
-import { MetricsModule } from '../src/metrics';
 import { DocManager, DocModule } from '../src/modules/doc';
 import { PrismaModule, PrismaService } from '../src/prisma';
 import { flushDB } from './utils';
@@ -19,7 +18,6 @@ const createModule = () => {
   return Test.createTestingModule({
     imports: [
       PrismaModule,
-      MetricsModule,
       CacheModule,
       EventEmitterModule.forRoot(),
       ConfigModule.forRoot(),

packages/backend/server/tests/history.spec.ts

@@ -6,7 +6,6 @@ import test from 'ava';
 import * as Sinon from 'sinon';
 
 import { ConfigModule } from '../src/config';
-import { MetricsModule } from '../src/metrics';
 import { DocHistoryManager } from '../src/modules/doc';
 import { PrismaModule, PrismaService } from '../src/prisma';
 import { flushDB } from './utils';
@@ -20,12 +19,7 @@ let db: PrismaService;
 test.beforeEach(async () => {
   await flushDB();
   m = await Test.createTestingModule({
-    imports: [
-      PrismaModule,
-      MetricsModule,
-      ScheduleModule.forRoot(),
-      ConfigModule.forRoot(),
-    ],
+    imports: [PrismaModule, ScheduleModule.forRoot(), ConfigModule.forRoot()],
     providers: [DocHistoryManager],
   }).compile();
 

packages/backend/server/tests/mailer.e2e.ts

@@ -12,7 +12,6 @@ import ava, { type TestFn } from 'ava';
 
 import { ConfigModule } from '../src/config';
 import { GqlModule } from '../src/graphql.module';
-import { MetricsModule } from '../src/metrics';
 import { AuthModule } from '../src/modules/auth';
 import { AuthService } from '../src/modules/auth/service';
 import { PrismaModule } from '../src/prisma';
@@ -44,7 +43,6 @@ test.beforeEach(async t => {
       PrismaModule,
       GqlModule,
       AuthModule,
-      MetricsModule,
       RateLimiterModule,
     ],
   }).compile();

packages/backend/server/tests/prometheus-metrics.spec.ts

@@ -1,78 +0,0 @@
-import { Test, TestingModule } from '@nestjs/testing';
-import test from 'ava';
-import { register } from 'prom-client';
-
-import { MetricsModule } from '../src/metrics';
-import { Metrics } from '../src/metrics/metrics';
-import { PrismaModule } from '../src/prisma';
-
-let metrics: Metrics;
-let module: TestingModule;
-
-test.beforeEach(async () => {
-  module = await Test.createTestingModule({
-    imports: [MetricsModule, PrismaModule],
-  }).compile();
-
-  metrics = module.get(Metrics);
-});
-
-test.afterEach.always(async () => {
-  await module.close();
-});
-
-test('should be able to increment counter', async t => {
-  metrics.socketIOEventCounter(1, { event: 'client-handshake' });
-  const socketIOCounterMetric = register.getSingleMetric('socket_io_counter');
-  t.truthy(socketIOCounterMetric);
-
-  t.truthy(
-    JSON.stringify((await socketIOCounterMetric!.get()).values) ===
-      '[{"value":1,"labels":{"event":"client-handshake"}}]'
-  );
-  t.pass();
-});
-
-test('should be able to timer', async t => {
-  let minimum: number;
-  {
-    const endTimer = metrics.socketIOEventTimer({ event: 'client-handshake' });
-    const a = performance.now();
-    await new Promise(resolve => setTimeout(resolve, 50));
-    const b = performance.now();
-    minimum = b - a;
-    endTimer();
-  }
-
-  let maximum: number;
-  {
-    const a = performance.now();
-    const endTimer = metrics.socketIOEventTimer({ event: 'client-handshake' });
-    await new Promise(resolve => setTimeout(resolve, 100));
-    endTimer();
-    const b = performance.now();
-    maximum = b - a;
-  }
-
-  const socketIOTimerMetric = register.getSingleMetric('socket_io_timer');
-  t.truthy(socketIOTimerMetric);
-
-  const observations = (await socketIOTimerMetric!.get()).values;
-
-  for (const observation of observations) {
-    if (
-      observation.labels.event === 'client-handshake' &&
-      'quantile' in observation.labels
-    ) {
-      t.truthy(
-        observation.value >= minimum / 1000,
-        'observation.value should be greater than minimum'
-      );
-      t.truthy(
-        observation.value <= maximum / 1000,
-        'observation.value should be less than maximum'
-      );
-    }
-  }
-  t.pass();
-});