Count active postgres and redis requests

Author: ajayyy

src/databases/Postgres.ts

@@ -33,6 +33,8 @@ export class Postgres implements IDatabase {
     private poolRead: Pool;
     private lastPoolReadFail = 0;
 
+    activePostgresRequests = 0;
+
     constructor(private config: DatabaseConfig) {}
 
     async init(): Promise<void> {
@@ -108,13 +110,15 @@ export class Postgres implements IDatabase {
             tries++;
 
             try {
+                this.activePostgresRequests++;
                 lastPool = this.getPool(type, options);
 
                 pendingQueries.push(savePromiseState(lastPool.query({ text: query, values: params })));
                 const currentPromises = [...pendingQueries];
                 if (options.useReplica && maxTries() - tries > 1) currentPromises.push(savePromiseState(timeoutPomise(this.config.postgresReadOnly.readTimeout)));
                 const queryResult = await nextFulfilment(currentPromises);
 
+                this.activePostgresRequests--;
                 switch (type) {
                     case "get": {
                         const value = queryResult.rows[0];
@@ -142,6 +146,7 @@ export class Postgres implements IDatabase {
             }
         } while (this.isReadQuery(type) && tries < maxTries());
 
+        this.activePostgresRequests--;
         throw new Error(`prepare (postgres): ${type} ${query} failed after ${tries} tries`);
     }
 

src/routes/getStatus.ts

@@ -2,8 +2,9 @@ import { db } from "../databases/databases";
 import { Logger } from "../utils/logger";
 import { Request, Response } from "express";
 import os from "os";
-import redis from "../utils/redis";
+import redis, { getRedisActiveRequests } from "../utils/redis";
 import { promiseOrTimeout } from "../utils/promise";
+import { Postgres } from "../databases/Postgres";
 
 export async function getStatus(req: Request, res: Response): Promise<Response> {
     const startTime = Date.now();
@@ -42,7 +43,9 @@ export async function getStatus(req: Request, res: Response): Promise<Response>
             redisProcessTime,
             loadavg: os.loadavg().slice(1), // only return 5 & 15 minute load average
             statusRequests,
-            hostname: os.hostname()
+            hostname: os.hostname(),
+            activePostgresRequests: (db as Postgres)?.activePostgresRequests,
+            activeRedisRequests: getRedisActiveRequests(),
         };
         return value ? res.send(JSON.stringify(statusValues[value])) : res.send(statusValues);
     } catch (err) {

src/utils/redis.ts

@@ -27,6 +27,7 @@ let exportClient: RedisSB = {
 
 let lastClientFail = 0;
 let lastReadFail = 0;
+let activeRequests = 0;
 
 if (config.redis?.enabled) {
     Logger.info("Connected to redis");
@@ -40,10 +41,13 @@ if (config.redis?.enabled) {
     const get = client.get.bind(client);
     const getRead = readClient?.get?.bind(readClient);
     exportClient.get = (key) => new Promise((resolve, reject) => {
+        activeRequests++;
         const timeout = config.redis.getTimeout ? setTimeout(() => reject(), config.redis.getTimeout) : null;
         const chosenGet = pickChoice(get, getRead);
         chosenGet(key).then((reply) => {
             if (timeout !== null) clearTimeout(timeout);
+
+            activeRequests--;
             resolve(reply);
         }).catch((err) => {
             if (chosenGet === get) {
@@ -52,6 +56,7 @@ if (config.redis?.enabled) {
                 lastReadFail = Date.now();
             }
 
+            activeRequests--;
             reject(err);
         });
     });
@@ -91,4 +96,8 @@ function pickChoice<T>(client: T, readClient: T): T {
     }
 }
 
+export function getRedisActiveRequests(): number {
+    return activeRequests;
+}
+
 export default exportClient;