Update Prometheus metrics to conform to best practices

src/controllers/metrics.ts

@@ -2,12 +2,11 @@ import { register } from 'prom-client';
 
 import { AppController } from '@/app.ts';
 import { DittoDB } from '@/db/DittoDB.ts';
-import { dbAvailableConnectionsGauge, dbPoolSizeGauge } from '@/metrics.ts';
+import { dbAvailableConnectionsGauge } from '@/metrics.ts';
 
 /** Prometheus/OpenMetrics controller. */
 export const metricsController: AppController = async (c) => {
   // Update some metrics at request time.
-  dbPoolSizeGauge.set(DittoDB.poolSize);
   dbAvailableConnectionsGauge.set(DittoDB.availableConnections);
 
   const metrics = await register.metrics();

src/controllers/nostr/relay.ts

@@ -12,7 +12,7 @@ import {
 import { AppController } from '@/app.ts';
 import { Conf } from '@/config.ts';
 import { relayInfoController } from '@/controllers/nostr/relay-info.ts';
-import { relayConnectionsGauge, relayEventCounter, relayMessageCounter } from '@/metrics.ts';
+import { relayConnectionsGauge, relayEventsCounter, relayMessagesCounter } from '@/metrics.ts';
 import * as pipeline from '@/pipeline.ts';
 import { RelayError } from '@/RelayError.ts';
 import { Storages } from '@/storages.ts';
@@ -54,10 +54,10 @@ function connectStream(socket: WebSocket, ip: string | undefined) {
 
     const result = n.json().pipe(n.clientMsg()).safeParse(e.data);
     if (result.success) {
-      relayMessageCounter.inc({ verb: result.data[0] });
+      relayMessagesCounter.inc({ verb: result.data[0] });
       handleMsg(result.data);
     } else {
-      relayMessageCounter.inc();
+      relayMessagesCounter.inc();
       send(['NOTICE', 'Invalid message.']);
     }
   };
@@ -130,7 +130,7 @@ function connectStream(socket: WebSocket, ip: string | undefined) {
 
   /** Handle EVENT. Store the event. */
   async function handleEvent([_, event]: NostrClientEVENT): Promise<void> {
-    relayEventCounter.inc({ kind: event.kind.toString() });
+    relayEventsCounter.inc({ kind: event.kind.toString() });
     try {
       // This will store it (if eligible) and run other side-effects.
       await pipeline.handleEvent(event, AbortSignal.timeout(1000));

src/db/KyselyLogger.ts

@@ -1,6 +1,6 @@
 import { Stickynotes } from '@soapbox/stickynotes';
 import { Logger } from 'kysely';
-import { dbQueryCounter, dbQueryTimeHistogram } from '@/metrics.ts';
+import { dbQueriesCounter, dbQueryDurationHistogram } from '@/metrics.ts';
 
 /** Log the SQL for queries. */
 export const KyselyLogger: Logger = (event) => {
@@ -9,8 +9,8 @@ export const KyselyLogger: Logger = (event) => {
   const { query, queryDurationMillis } = event;
   const { sql, parameters } = query;
 
-  dbQueryCounter.inc();
+  dbQueriesCounter.inc();
-  dbQueryTimeHistogram.observe(queryDurationMillis);
+  dbQueryDurationHistogram.observe(queryDurationMillis);
 
   console.debug(
     sql,

src/firehose.ts

@@ -2,7 +2,7 @@ import { Semaphore } from '@lambdalisue/async';
 import { Stickynotes } from '@soapbox/stickynotes';
 
 import { Conf } from '@/config.ts';
-import { firehoseEventCounter } from '@/metrics.ts';
+import { firehoseEventsCounter } from '@/metrics.ts';
 import { Storages } from '@/storages.ts';
 import { nostrNow } from '@/utils.ts';
 
@@ -23,7 +23,7 @@ export async function startFirehose(): Promise<void> {
     if (msg[0] === 'EVENT') {
       const event = msg[2];
       console.debug(`NostrEvent<${event.kind}> ${event.id}`);
-      firehoseEventCounter.inc({ kind: event.kind });
+      firehoseEventsCounter.inc({ kind: event.kind });
 
       sem.lock(async () => {
         try {

src/metrics.ts

@@ -1,86 +1,81 @@
 import { Counter, Gauge, Histogram } from 'prom-client';
 
-export const httpRequestCounter = new Counter({
+export const httpRequestsCounter = new Counter({
-  name: 'http_requests_total',
+  name: 'ditto_http_requests_total',
   help: 'Total number of HTTP requests',
   labelNames: ['method'],
 });
 
-export const httpResponseCounter = new Counter({
+export const httpResponsesCounter = new Counter({
-  name: 'http_responses_total',
+  name: 'ditto_http_responses_total',
   help: 'Total number of HTTP responses',
   labelNames: ['method', 'path', 'status'],
 });
 
 export const streamingConnectionsGauge = new Gauge({
-  name: 'streaming_connections',
+  name: 'ditto_streaming_connections',
   help: 'Number of active connections to the streaming API',
 });
 
 export const fetchCounter = new Counter({
-  name: 'fetch_total',
+  name: 'ditto_fetch_total',
   help: 'Total number of fetch requests',
   labelNames: ['method'],
 });
 
-export const firehoseEventCounter = new Counter({
+export const firehoseEventsCounter = new Counter({
-  name: 'firehose_events_total',
+  name: 'ditto_firehose_events_total',
   help: 'Total number of Nostr events processed by the firehose',
   labelNames: ['kind'],
 });
 
-export const pipelineEventCounter = new Counter({
+export const pipelineEventsCounter = new Counter({
-  name: 'pipeline_events_total',
+  name: 'ditto_pipeline_events_total',
   help: 'Total number of Nostr events processed by the pipeline',
   labelNames: ['kind'],
 });
 
-export const policyEventCounter = new Counter({
+export const policyEventsCounter = new Counter({
-  name: 'policy_events_total',
+  name: 'ditto_policy_events_total',
   help: 'Total number of policy OK responses',
   labelNames: ['ok'],
 });
 
-export const relayEventCounter = new Counter({
+export const relayEventsCounter = new Counter({
-  name: 'relay_events_total',
+  name: 'ditto_relay_events_total',
   help: 'Total number of EVENT messages processed by the relay',
   labelNames: ['kind'],
 });
 
-export const relayMessageCounter = new Counter({
+export const relayMessagesCounter = new Counter({
-  name: 'relay_messages_total',
+  name: 'ditto_relay_messages_total',
   help: 'Total number of Nostr messages processed by the relay',
   labelNames: ['verb'],
 });
 
 export const relayConnectionsGauge = new Gauge({
-  name: 'relay_connections',
+  name: 'ditto_relay_connections',
   help: 'Number of active connections to the relay',
 });
 
-export const dbQueryCounter = new Counter({
+export const dbQueriesCounter = new Counter({
-  name: 'db_query_total',
+  name: 'ditto_db_queries_total',
   help: 'Total number of database queries',
   labelNames: ['kind'],
 });
 
-export const dbEventCounter = new Counter({
+export const dbEventsCounter = new Counter({
-  name: 'db_events_total',
+  name: 'ditto_db_events_total',
   help: 'Total number of database inserts',
   labelNames: ['kind'],
 });
 
-export const dbPoolSizeGauge = new Gauge({
-  name: 'db_pool_size',
-  help: 'Number of connections in the database pool',
-});
-
 export const dbAvailableConnectionsGauge = new Gauge({
-  name: 'db_available_connections',
+  name: 'ditto_db_available_connections',
   help: 'Number of available connections in the database pool',
 });
 
-export const dbQueryTimeHistogram = new Histogram({
+export const dbQueryDurationHistogram = new Histogram({
-  name: 'db_query_duration_ms',
+  name: 'ditto_db_query_duration_ms',
   help: 'Duration of database queries',
 });

src/middleware/metricsMiddleware.ts

@@ -1,12 +1,12 @@
 import { MiddlewareHandler } from '@hono/hono';
 
-import { httpRequestCounter, httpResponseCounter } from '@/metrics.ts';
+import { httpRequestsCounter, httpResponsesCounter } from '@/metrics.ts';
 
 /** Prometheus metrics middleware that tracks HTTP requests by methods and responses by status code. */
 export const metricsMiddleware: MiddlewareHandler = async (c, next) => {
   // HTTP Request.
   const { method } = c.req;
-  httpRequestCounter.inc({ method });
+  httpRequestsCounter.inc({ method });
 
   // Wait for other handlers to run.
   await next();
@@ -16,5 +16,5 @@ export const metricsMiddleware: MiddlewareHandler = async (c, next) => {
   // Get a parameterized path name like `/posts/:id` instead of `/posts/1234`.
   // Tries to find actual route names first before falling back on potential middleware handlers like `app.use('*')`.
   const path = c.req.matchedRoutes.find((r) => r.method !== 'ALL')?.path ?? c.req.routePath;
-  httpResponseCounter.inc({ method, status, path });
+  httpResponsesCounter.inc({ method, status, path });
 };

src/pipeline.ts

@@ -8,7 +8,7 @@ import { Conf } from '@/config.ts';
 import { DittoDB } from '@/db/DittoDB.ts';
 import { deleteAttachedMedia } from '@/db/unattached-media.ts';
 import { DittoEvent } from '@/interfaces/DittoEvent.ts';
-import { pipelineEventCounter, policyEventCounter } from '@/metrics.ts';
+import { pipelineEventsCounter, policyEventsCounter } from '@/metrics.ts';
 import { RelayError } from '@/RelayError.ts';
 import { AdminSigner } from '@/signers/AdminSigner.ts';
 import { hydrateEvents } from '@/storages/hydrate.ts';
@@ -40,7 +40,7 @@ async function handleEvent(event: DittoEvent, signal: AbortSignal): Promise<void
   if (encounterEvent(event)) return;
   if (await existsInDB(event)) return;
   debug(`NostrEvent<${event.kind}> ${event.id}`);
-  pipelineEventCounter.inc({ kind: event.kind });
+  pipelineEventsCounter.inc({ kind: event.kind });
 
   if (event.kind !== 24133) {
     await policyFilter(event);
@@ -71,7 +71,7 @@ async function policyFilter(event: NostrEvent): Promise<void> {
 
   try {
     const result = await policyWorker.call(event);
-    policyEventCounter.inc({ ok: String(result[2]) });
+    policyEventsCounter.inc({ ok: String(result[2]) });
     debug(JSON.stringify(result));
     RelayError.assert(result);
   } catch (e) {

src/storages/EventsDB.ts

@@ -17,7 +17,7 @@ import { nip27 } from 'nostr-tools';
 
 import { Conf } from '@/config.ts';
 import { DittoDatabase } from '@/db/DittoDB.ts';
-import { dbEventCounter } from '@/metrics.ts';
+import { dbEventsCounter } from '@/metrics.ts';
 import { RelayError } from '@/RelayError.ts';
 import { purifyEvent } from '@/storages/hydrate.ts';
 import { isNostrId, isURL } from '@/utils.ts';
@@ -73,7 +73,7 @@ class EventsDB implements NStore {
   async event(event: NostrEvent, opts: { signal?: AbortSignal; timeout?: number } = {}): Promise<void> {
     event = purifyEvent(event);
     this.console.debug('EVENT', JSON.stringify(event));
-    dbEventCounter.inc({ kind: event.kind });
+    dbEventsCounter.inc({ kind: event.kind });
 
     if (await this.isDeletedAdmin(event)) {
       throw new RelayError('blocked', 'event deleted by admin');