Drizzle Team•15mo ago

Too many clients already (!?)

Hey guys, been using Drizzle for a few weeks now and I think since last week this issue has started (look at screenshot). I'm using the postgrespaackge to connect Drizzle to my PostgreSQL database that's deployed to Railway. Drizzle connection code 👇 :

import { env } from "@/env.mjs";
import { drizzle } from "drizzle-orm/postgres-js";
import postgres from "postgres";

import * as schema from "./schemas";

const connection = postgres(env.DB_URL);
export const dbClient = drizzle(connection, { logger: true, schema });

import { env } from "@/env.mjs";
import { drizzle } from "drizzle-orm/postgres-js";
import postgres from "postgres";

import * as schema from "./schemas";

const connection = postgres(env.DB_URL);
export const dbClient = drizzle(connection, { logger: true, schema });

Dunno what I might be doing wrong, please help me 🙏

6 Replies

Angelelz•15mo ago

If you're in development and use HMR, everytime you make changes to your files a new postgres instance will be created You'll need to create a singleton to avoid that problem I suspect that is your issue, but I might be wrong Here is an example I found of a singleton implementation: https://discordapp.com/channels/1043890932593987624/1043890932593987627/1141696708099711148

dBranded1OP•15mo ago

that makes a lot of sense, I'm gonna try it tomorrow and then come back here to give an update, thank you in advance 🤝

zendev•14mo ago

Think I'm running into the same issue, getting this message from tRPC: tRPC failed: no more connections allowed (max_client_conn) Is this only going to be an issue in dev? Nothing here impacts production?

t•13mo ago

Yes, this is a dev-only issue due to HMR, I solved it like this:

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

import { env } from "~/lib/env/server.mjs";

import type { PostgresJsDatabase } from "drizzle-orm/postgres-js";

// Fix for "sorry, too many clients already"
declare global {
  // eslint-disable-next-line no-var -- only var works here
  var db: PostgresJsDatabase | undefined;
}

let db: PostgresJsDatabase;

if (env.NODE_ENV === "production") {
  db = drizzle(postgres(env.DATABASE_URL));
} else {
  if (!global.db) global.db = drizzle(postgres(env.DATABASE_URL));

  db = global.db;
}

export { db };

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

import { env } from "~/lib/env/server.mjs";

import type { PostgresJsDatabase } from "drizzle-orm/postgres-js";

// Fix for "sorry, too many clients already"
declare global {
  // eslint-disable-next-line no-var -- only var works here
  var db: PostgresJsDatabase | undefined;
}

let db: PostgresJsDatabase;

if (env.NODE_ENV === "production") {
  db = drizzle(postgres(env.DATABASE_URL));
} else {
  if (!global.db) global.db = drizzle(postgres(env.DATABASE_URL));

  db = global.db;
}

export { db };

Aryan•10mo ago

For create-t3-app users, the schema will be in another file - not in your main Drizzle client file by default. Just add this generic type to PostgresJsDatabase to fix this issue:

type PostgresJsDatabase<typeof schema>;

type PostgresJsDatabase<typeof schema>;

So the final file will look like:

// index.ts
import { drizzle } from "drizzle-orm/postgres-js";
import postgres from "postgres";

import { env } from "~/env.js";
import * as schema from "./schema"; 

import { type PostgresJsDatabase } from "drizzle-orm/postgres-js";

// Fix for "sorry, too many clients already"
declare global {
  // eslint-disable-next-line no-var -- only var works here
  var db: PostgresJsDatabase<typeof schema> | undefined;
}

let db: PostgresJsDatabase<typeof schema>;

if (env.NODE_ENV === "production") {
  db = drizzle(postgres(env.DATABASE_URL), { schema });
} else {
  if (!global.db) global.db = drizzle(postgres(env.DATABASE_URL), { schema });

  db = global.db;
}

export { db };

// index.ts
import { drizzle } from "drizzle-orm/postgres-js";
import postgres from "postgres";

import { env } from "~/env.js";
import * as schema from "./schema"; 

import { type PostgresJsDatabase } from "drizzle-orm/postgres-js";

// Fix for "sorry, too many clients already"
declare global {
  // eslint-disable-next-line no-var -- only var works here
  var db: PostgresJsDatabase<typeof schema> | undefined;
}

let db: PostgresJsDatabase<typeof schema>;

if (env.NODE_ENV === "production") {
  db = drizzle(postgres(env.DATABASE_URL), { schema });
} else {
  if (!global.db) global.db = drizzle(postgres(env.DATABASE_URL), { schema });

  db = global.db;
}

export { db };

onyxngo•3mo ago

I get the too many clients error on railway.app, but it runs perfect on localhost and vercel... What could be wrong: import { drizzle } from "drizzle-orm/postgres-js" import postgres from "postgres" import * as schema from "./schema" import { type PostgresJsDatabase } from "drizzle-orm/postgres-js" // Declare global to prevent multiple instances during hot reloading in development declare global { // eslint-disable-next-line no-var var db: PostgresJsDatabase<typeof schema> | undefined } const connectionPool = postgres(process.env.DATABASE_URL!, { max: 20, // Reduced to a more reasonable number idle_timeout: 30, max_lifetime: 60 * 30, // 30 minutes }) function createDb() { return drizzle(connectionPool, { schema }) } let db: PostgresJsDatabase<typeof schema> if (process.env.NODE_ENV === "production") { db = createDb() } else { if (!global.db) { global.db = createDb() } db = global.db } export { db }

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Too many clients already (!?)