From f9cd63724cbd5e5a17978e2a5a9085b49a535779 Mon Sep 17 00:00:00 2001
From: Kamil Kisiela <kamil.kisiela@gmail.com>
Date: Fri, 25 Nov 2022 09:40:38 +0100
Subject: [PATCH] Introduce tokens_http_requests and
 usage_tokens_duration_seconds metrics (#684)

---
 packages/services/tokens/src/api.ts    | 23 ++++++++++++++++++++++-
 packages/services/usage/src/index.ts   | 13 ++++++++++++-
 packages/services/usage/src/metrics.ts |  6 ++++++
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/packages/services/tokens/src/api.ts b/packages/services/tokens/src/api.ts
index eef83e470..07750e9a6 100644
--- a/packages/services/tokens/src/api.ts
+++ b/packages/services/tokens/src/api.ts
@@ -1,4 +1,4 @@
-import { createErrorHandler } from '@hive/service-common';
+import { createErrorHandler, metrics } from '@hive/service-common';
 import * as trpc from '@trpc/server';
 import { inferProcedureInput, inferProcedureOutput } from '@trpc/server';
 import type { FastifyLoggerInstance } from 'fastify';
@@ -7,6 +7,18 @@ import { useCache } from './cache';
 import { createHash } from 'crypto';
 import { Lru as LruType } from 'tiny-lru';
 
+const httpRequests = new metrics.Counter({
+  name: 'tokens_http_requests',
+  help: 'Number of http requests',
+  labelNames: ['path'],
+});
+
+const httpRequestDuration = new metrics.Histogram({
+  name: 'tokens_http_request_duration_seconds',
+  help: 'Duration of an http request',
+  labelNames: ['path'],
+});
+
 const TARGET_VALIDATION = z
   .object({
     targetId: z.string().nonempty(),
@@ -72,6 +84,15 @@ export type Context = {
 
 export const tokensApiRouter = trpc
   .router<Context>()
+  .middleware(async ({ path, next }) => {
+    const stopTimer = httpRequestDuration.startTimer({ path });
+    httpRequests.inc({ path });
+    try {
+      return await next();
+    } finally {
+      stopTimer();
+    }
+  })
   .query('targetTokens', {
     input: TARGET_VALIDATION,
     async resolve({ ctx, input }) {
diff --git a/packages/services/usage/src/index.ts b/packages/services/usage/src/index.ts
index 6386b37ea..926fc2ea7 100644
--- a/packages/services/usage/src/index.ts
+++ b/packages/services/usage/src/index.ts
@@ -15,6 +15,7 @@ import {
   httpRequestsWithNoAccess,
   collectDuration,
   droppedReports,
+  tokensDuration,
 } from './metrics';
 import type { IncomingLegacyReport, IncomingReport } from './types';
 import { createUsageRateLimit } from './rate-limit';
@@ -96,11 +97,14 @@ async function main() {
           return;
         }
 
+        const stopTokensDurationTimer = tokensDuration.startTimer();
         const tokenInfo = await tokens.fetch(token);
-
         const maskedToken = maskToken(token);
 
         if (tokens.isNotFound(tokenInfo)) {
+          stopTokensDurationTimer({
+            status: 'not_found',
+          });
           httpRequestsWithNonExistingToken.inc();
           req.log.info('Token not found (token=%s)', maskedToken);
           res.status(400).send('Missing token'); // eslint-disable-line @typescript-eslint/no-floating-promises -- false positive, FastifyReply.then returns void
@@ -109,12 +113,19 @@ async function main() {
 
         // We treat collected operations as part of registry
         if (tokens.isNoAccess(tokenInfo)) {
+          stopTokensDurationTimer({
+            status: 'no_access',
+          });
           httpRequestsWithNoAccess.inc();
           req.log.info('No access (token=%s)', maskedToken);
           res.status(403).send('No access'); // eslint-disable-line @typescript-eslint/no-floating-promises -- false positive, FastifyReply.then returns void
           return;
         }
 
+        stopTokensDurationTimer({
+          status: 'success',
+        });
+
         if (
           await rateLimit?.isRateLimited({
             id: tokenInfo.target,
diff --git a/packages/services/usage/src/metrics.ts b/packages/services/usage/src/metrics.ts
index 4c1fad374..58df3bcc4 100644
--- a/packages/services/usage/src/metrics.ts
+++ b/packages/services/usage/src/metrics.ts
@@ -10,6 +10,12 @@ export const tokenRequests = new metrics.Counter({
   help: 'Number of requests to Tokens service',
 });
 
+export const tokensDuration = new metrics.Histogram({
+  name: 'usage_tokens_duration_seconds',
+  help: 'Duration of an HTTP Request to Tokens service in seconds',
+  labelNames: ['status'],
+});
+
 export const httpRequests = new metrics.Counter({
   name: 'usage_http_requests',
   help: 'Number of http requests',