guide · dead letter queue

Read it, retry it, clear it.

The four things you actually do with a Dead Letter Queue: narrow it down to the entries you care about, put a subset back, check whether the pile is growing, and empty it when the cause is fixed.

Common Tasks

Filter entries

Bun

await queue.getDlqAsync({ reason: 'max_attempts_exceeded' });         // by emitted reason
await queue.getDlqAsync({ olderThan: Date.now() - 86400000 });        // older than 24h
await queue.getDlqAsync({ newerThan: Date.now() - 3600000 });         // last hour
await queue.getDlqAsync({ retriable: true });                         // auto-retry is due now
await queue.getDlqAsync({ limit: 10, offset: 20 });                   // pagination

Node.js / Deno

The SDK’s getDlq() returns jobs only. Use the HTTP endpoint for full entry metadata, then filter the returned page in the client:

const response = await fetch('http://localhost:6790/queues/emails/dlq?limit=100&offset=0');
const { entries, total } = await response.json();
const stalled = entries.filter((entry) => entry.reason === 'stalled');

Python

The SDK’s get_dlq() returns jobs only. The standard library can read full entries from HTTP:

import json
from urllib.request import urlopen

with urlopen("http://localhost:6790/queues/emails/dlq?limit=100&offset=0") as response:
    payload = json.load(response)
stalled = [entry for entry in payload["entries"] if entry["reason"] == "stalled"]

PHP

The SDK’s getDlq() returns jobs only. Read full entries through HTTP:

$json = file_get_contents('http://localhost:6790/queues/emails/dlq?limit=100&offset=0');
$payload = json_decode($json, true, flags: JSON_THROW_ON_ERROR);
$stalled = array_filter($payload['entries'], fn ($entry) => $entry['reason'] === 'stalled');

Go

The SDK’s GetDlq() returns jobs only. Read full entries through HTTP with the standard library:

response, err := http.Get("http://localhost:6790/queues/emails/dlq?limit=100&offset=0")
if err != nil { return err }
defer response.Body.Close()

var payload struct { Entries []map[string]any `json:"entries"` }
err = json.NewDecoder(response.Body).Decode(&payload)

Rust

The Rust SDK’s get_dlq() returns jobs only. Use the broker HTTP endpoint (and your application’s HTTP/JSON crate) for full entries:

curl 'http://localhost:6790/queues/emails/dlq?limit=100&offset=0'

Elixir

The Elixir SDK’s dlq/2 returns jobs only. Use the broker HTTP endpoint for full entries:

curl 'http://localhost:6790/queues/emails/dlq?limit=100&offset=0'

The Bun async API applies reason, time, due-retry, expiry, limit, and offset filters server-side in both embedded and TCP modes. The HTTP endpoint currently supports only limit and offset; external clients must filter that page locally. retriable: true means nextRetryAt is already due, not merely that the entry has retry budget remaining.

Retry selectively

Bun

queue.retryDlq();                                          // retry everything
queue.retryDlq('job-123');                                 // retry one job
queue.retryDlqByFilter({ reason: 'stalled' });             // TCP is fire-and-forget
const filtered = await queue.retryDlqByFilterAsync({ reason: 'stalled' }); // authoritative count
const n = await queue.retryDlqAsync();                     // retry and get the count (TCP too)

Node.js / Deno

await queue.retryDlq();                       // retry everything
await queue.retryDlq('job-123');              // retry one job
await queue.retryJobs({ count: 100 });        // retry only the first 100 entries

Python

queue.retry_dlq()                    # retry everything
queue.retry_dlq("job-123")           # retry one job
queue.retry_dlq(count=100)           # retry only the first 100 entries

PHP

$queue->retryDlq();                  // retry everything
$queue->retryDlq('job-123');         // retry one job
$queue->retryDlq(null, 100);         // retry only the first 100 entries

Go

n, err := queue.RetryDlq("", 0)         // retry everything
n, err = queue.RetryDlq("job-123", 0)   // retry one job
n, err = queue.RetryDlq("", 100)        // retry only the first 100 entries

Rust

queue.retry_dlq(None, None)?;              // retry everything
queue.retry_dlq(Some("job-123"), None)?;   // retry one job
queue.retry_dlq(None, Some(100))?;         // retry only the first 100 entries

Elixir

{:ok, n} = Bunqueue.Queue.retry_dlq(queue)               # retry everything
{:ok, _} = Bunqueue.Queue.retry_dlq(queue, "job-123")    # retry one job
{:ok, _} = Bunqueue.Queue.retry_dlq(queue, nil, 100)     # retry only the first 100

Check DLQ health

Bun

const stats = await queue.getDlqStatsAsync();
console.log(stats.total);         // total entries
console.log(stats.byReason);      // { max_attempts_exceeded: 5, stalled: 2, ... }
console.log(stats.pendingRetry);  // entries whose auto-retry time is due

A simple alert loop:

setInterval(async () => {
  const stats = await queue.getDlqStatsAsync();
  if (stats.total > 100) alertOps('High DLQ count', stats);
}, 30000);

Node.js / Deno

const { stats } = await (await fetch(
  'http://localhost:6790/queues/emails/dlq/stats'
)).json();

Python

with urlopen("http://localhost:6790/queues/emails/dlq/stats") as response:
    stats = json.load(response)["stats"]

PHP

$payload = json_decode(
    file_get_contents('http://localhost:6790/queues/emails/dlq/stats'),
    true,
    flags: JSON_THROW_ON_ERROR,
);
$stats = $payload['stats'];

Go

response, err := http.Get("http://localhost:6790/queues/emails/dlq/stats")
// Decode response.Body and read the top-level "stats" object.

Rust

curl 'http://localhost:6790/queues/emails/dlq/stats'

Elixir

curl 'http://localhost:6790/queues/emails/dlq/stats'

Use synchronous getDlqStats() for a Bun embedded snapshot and getDlqStatsAsync() for an authoritative Bun result in either runtime. The other SDKs do not expose a stats helper yet; the HTTP result is authoritative.

Purge

Bun

const purged = queue.purgeDlq();             // permanently deletes all entries
const n = await queue.purgeDlqAsync();       // same, but waits and returns the count (TCP too)

Node.js / Deno

const purged = await queue.purgeDlq();       // permanently deletes all entries, returns the count

Python

purged = queue.purge_dlq()       # permanently deletes all entries, returns the count

PHP

$purged = $queue->purgeDlq();    // permanently deletes all entries, returns the count

Go

purged, err := queue.PurgeDlq()  // permanently deletes all entries, returns the count

Rust

let purged = queue.purge_dlq()?; // permanently deletes all entries, returns the count

Elixir

{:ok, purged} = Bunqueue.Queue.purge_dlq(queue)  # deletes all entries, returns the count

Where to go next

DLQ Operations from the Queue Object	The same operations from an existing Queue instance
Dead Letter Queue	What the DLQ is, and a first look at what failed
Automatic DLQ Retry with Backoff	Let bunqueue re-queue dead entries on a backoff
DLQ Configuration	autoRetry, maxAge, maxEntries and the defaults
DLQ Reference	Failure reasons, entry shape, every DLQ method