[BUG][Supabase][Postgres client] Exhausted connection pool

[atanaskanchev]

What version of drizzle-orm are you using?

0.27.2

What version of drizzle-kit are you using?

0.19.10

Describe the Bug

PostgresError: remaining connection slots are reserved for non-replication superuser connections
    at ErrorResponse (webpack-internal:///(rsc)/../../node_modules/postgres/src/connection.js:528:70)
    at handle (webpack-internal:///(rsc)/../../node_modules/postgres/src/connection.js:335:728)
    at Socket.data (webpack-internal:///(rsc)/../../node_modules/postgres/src/connection.js:223:17)
    at Socket.emit (node:events:513:28)
    at addChunk (node:internal/streams/readable:324:12)
    at readableAddChunk (node:internal/streams/readable:297:9)
    at Readable.push (node:internal/streams/readable:234:10)
    at TCP.onStreamRead (node:internal/stream_base_commons:190:23)
    at TCP.callbackTrampoline (node:internal/async_hooks:130:17)

Expected behavior

No response

Environment & setup

Client setup

import { drizzle, type PostgresJsDatabase } from 'drizzle-orm/postgres-js'
import postgres from 'postgres'

import { schema } from '@lf/services-drizzle-orm-schema'

if (!process.env.DATABASE_URL) {
  throw new Error('DATABASE_URL is missing')
}

const connectionString = process.env.DATABASE_URL

const queryClient = postgres(connectionString)

export const db: PostgresJsDatabase<typeof schema> = drizzle(queryClient, { schema, logger: true })```

[Lenghak]

Hello, @atanaskanchev! I was wondering if you had already solved this issue since I myself have been struggling with it for quite some time, and it is getting more frequent right now. I would love to hear from you if you have any workarounds for this.

[NovaBG03]

I'm experiencing the same problem

[mirsahebali]

same here too

[hawkup]

In my case, this issue arises due to hot reloading during development. With each hot reload, a new Drizzle instance is created, consuming a new connection.
To resolve it, I created a global Drizzle instance to prevent it from being recreated with every hot reload.

Here's my code, which I adapted from the Prisma version.

import { drizzle } from "drizzle-orm/postgres-js"
import postgres from "postgres"

declare module global {
  let postgresSqlClient: ReturnType<typeof postgres> | undefined
}

let postgresSqlClient

const databaseUrl = 'postgres://postgres:adminadmin@0.0.0.0:5432/db'

if (process.env.NODE_ENV !== "production") {
  if (!global.postgresSqlClient) {
    global.postgresSqlClient = postgres(databaseUrl)
  }
  postgresSqlClient = global.postgresSqlClient
} else {
  postgresSqlClient = postgres(databaseUrl)
}

export const db = drizzle(postgresSqlClient)

Reference

• prevent-hot-reloading-from-creating-new-instances-of-prismaclient
• "FATAL: sorry, too many clients already" postgres error in develop mode on  prisma/prisma#1983 (comment)

[Angelelz]

This is know issue if you're using HMR. The solution is given in the comment above.