---
title: "Queues"
description: "Durable message queues for your applications, standard and FIFO, with long-poll receive, HTTPS push and dead-letter queues."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.ezghcloud.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Queues

EZGH Queues stores messages between the parts of your application that produce work and the
parts that do it. Producers send messages to a queue. Consumers either receive them with a long
poll and acknowledge each one when they've handled it, or have Queues push them in batches to an
HTTPS endpoint. A message that keeps failing moves to a dead-letter queue, where you can inspect it
and send it back.

- **Standard queues** deliver every message at least once, in roughly the order sent.
- **FIFO queues** deliver the messages of each message group in order, one batch at a time, and
  don't store a send whose deduplication ID they saw in the last 5 minutes.

- [Quickstart](/queues/quickstart) — Create a queue, send a message, receive it and acknowledge it, with curl or the ezgh CLI.
- [Concepts](/queues/concepts) — Queues, messages, visibility timeouts, receipt handles and retention.
- [Pull consumers](/queues/consumers) — Long-poll receive, acknowledging, and extending or releasing messages.
- [Push subscriptions](/queues/push) — Batches pushed to your HTTPS endpoint, signature checks and partial failures.
- [FIFO queues](/queues/fifo) — Message groups, ordering and deduplication.
- [Dead-letter queues](/queues/dead-letter-queues) — Redrive policies, inspecting failed messages and moving them back.
- [IAM recipes](/queues/iam) — Producers, consumers, operators, and policies for one queue.
- [Queues and Workflows](/queues/workflows) — Start workflow runs from a queue, resume waiting runs, send from a step, and get run results.
- [Limits](/queues/limits) — Sizes, rate limits, quotas and usage.

## Hosts

| Host | What it serves |
| --- | --- |
| `https://queues-api.ezghcloud.com` | The [Queues API](/queues-api): queues, subscriptions, purges, redrives and limits; [sending](/queues-api/SendMessages/) and [peeking at](/queues-api/PeekMessages/) messages. Called with an API key or your console session |
| `https://queues-live.ezghcloud.com` | [Receiving](/queues-api/ReceiveMessages/) messages, with an API key or your console session; acknowledging them and changing their visibility, with their [receipt handles](/queues/consumers#acknowledge-messages) and no credential |

The console's **Queues** pages (in Application integration) use both hosts.

## Permissions

| Action | Allows | Checked against |
| --- | --- | --- |
| `queues.queues.list` | List queues | Project |
| `queues.queues.get` | View a queue, its settings and its message counts | Queue |
| `queues.queues.create` | Create queues | Project |
| `queues.queues.update` | Change a queue's settings and tags | Queue |
| `queues.queues.delete` | Delete a queue, its subscription and its messages | Queue |
| `queues.queues.purge` | Delete every message in a queue | Queue |
| `queues.messages.send` | Send messages | Queue |
| `queues.messages.receive` | Receive messages, which hides them from other consumers | Queue |
| `queues.messages.peek` | View a queue's messages without receiving them | Queue |
| `queues.redrives.start` | Move a dead-letter queue's messages back | The dead-letter queue, and the destination queue when you name one |
| `queues.redrives.list` | List a dead-letter queue's redrives | Queue |
| `queues.redrives.get` | View a redrive's progress | Queue |
| `queues.subscriptions.list` | List subscriptions | Project |
| `queues.subscriptions.get` | View a subscription and its delivery status | Subscription |
| `queues.subscriptions.create` | Create a queue's subscription | Queue |
| `queues.subscriptions.update` | Change a subscription, or rotate its signing secret | Subscription |
| `queues.subscriptions.delete` | Delete a subscription | Subscription |
| `queues.subscriptions.pause` | Pause and resume a subscription | Subscription |
| `queues.limits.get` | View a project's rate limits and caps | Project |

Acknowledging a message and changing its visibility need no permission: the message's receipt
handle, returned by a receive, is what allows them. See [Pull consumers](/queues/consumers).

| Managed policy | What it allows |
| --- | --- |
| `QueuesFullAccess` | Every `queues.*` action. |
| `QueuesReadOnlyAccess` | Every list and view action, including peeking at messages: queues and their counts, messages, redrives, subscriptions and limits. Not receiving, which consumes messages. |

`ReadOnlyAccess` allows what `QueuesReadOnlyAccess` does. `AdministratorAccess` and the root user
can do all of these. See [IAM recipes](/queues/iam).

## Resources

| Resource | Resource name |
| --- | --- |
| Queue | `ezgh:us-west-1:<org>:<project>:que_<slug>` |
| Subscription | `ezgh:us-west-1:<org>:<project>:qsb_<slug>` |

Paths name queues and subscriptions by their `id`, a UUID. The slug (`que_` or `qsb_` and 12
characters) is in the resource name.

## Data

- **Message bodies and attribute values are never logged or recorded in Trails.** A message is
  kept until it's acknowledged, its queue's retention ends, or it's purged or deleted with its
  queue.
- **A subscription's signing secret** is stored encrypted and shown once, when it's created or
  rotated.

> **Caution**
>
> EZGH doesn't back up stored messages yet. If stored data were lost, messages that hadn't been
> acknowledged would be lost with it.

## Trails

Queues' events have the event source `queues.ezghcloud.com`.

- **Recorded:** every call to the Queues API, as the [rules for reads](/trails#what-trails-records)
  say, with event names such as `CreateQueue`, `PurgeQueue`, `StartRedrive`, `CreateSubscription`
  and `RotateSubscriptionSecret`. [PeekMessages](/queues-api/PeekMessages/) is recorded as a
  data event, without the messages.
- **Recorded only when refused:** [SendMessages](/queues-api/SendMessages/) and
  [ReceiveMessages](/queues-api/ReceiveMessages/), for example a `403`.
- **Never recorded:** acknowledgements and visibility changes, message bodies and attributes, and
  signing secrets.

Source: https://docs.ezghcloud.com/queues/index.mdx