Uncatchable exception on idle in transcation timeout

[k0nserv]

Hello!

If you trigger a connection termination due to idle in transaction timeout postgres throws an error that is not catchable from the callsite.

Minimal repro:

const postgres = require("postgres");

const sql = postgres({
  host: process.env.PGHOST || "localhost",
  port: process.env.PGPORT ? Number(process.env.PGPORT) : 5432,
  database: process.env.PGDATABASE || "postgres_connection_issue",
  user: process.env.PGUSER,
});

const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function main() {
  console.log("\n--- minimal idle timeout repro ---");
  try {
    await sql.begin(async (tx) => {
      await tx`SET idle_in_transaction_session_timeout = 50`;
      await sleep(200);
    });
  } catch (err) {
    // The driver throws a normal connection-closed error after the server kills
    // the backend for idling in a transaction. We log that and keep going.
    console.error("caught error:", err?.message || err);
  }
}

process.on("uncaughtException", (err) => {
  console.error("uncaught exception:", err);
});

main();

The stack trace is

    at Immediate.nextWrite ([..]/node_modules/postgres/cjs/src/connection.js:250:22)
    at process.processImmediate (node:internal/timers:483:21)

This seems to be a race condition between nextWrite and the socket being closed.

This becomes a problem because the exception cannot be caught without using process.on, ideally this exception would not be raised.

[SagarJadhav30]

@k0nserv Hello Sir i will solve this Uncatchable exception on idle in transcation timeout #1133

i understand
Race Condition
nextWrite() tries to write but socket is already closed → uncaught exception → uncaughtException event required.

if ( this.socket.destroyed || this.socket.closed)
{
// abort queued writes gracefully
return;
}