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@ -3,61 +3,20 @@ title: "RQ: Connections"
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layout: docs
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layout: docs
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---
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---
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Although RQ features the `use_connection()` command for convenience, it
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### The connection parameter
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is deprecated, since it pollutes the global namespace. Instead, prefer explicit
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connection management using the `with Connection(...):` context manager, or
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pass in Redis connection references to queues directly.
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Each RQ object (queues, workers, jobs) has a `connection` keyword
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## Single Redis connection (easy)
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argument that can be passed to the constructor - this is the recommended way of handling connections.
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<div class="warning">
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<img style="float: right; margin-right: -60px; margin-top: -38px" src="/img/warning.png" />
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<strong>Note:</strong>
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<p>
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The use of <code>use_connection</code> is deprecated.
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Please don't use <code>use_connection</code> in your scripts.
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Instead, use explicit connection management.
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</p>
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</div>
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In development mode, to connect to a default, local Redis server:
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```python
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from rq import use_connection
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use_connection()
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```
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In production, to connect to a specific Redis server:
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```python
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```python
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from redis import Redis
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from redis import Redis
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from rq import use_connection
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from rq import Queue
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redis = Redis('my.host.org', 6789, password='secret')
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redis = Redis('localhost', 6789)
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use_connection(redis)
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q = Queue(connection=redis)
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```
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```
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Be aware of the fact that `use_connection` pollutes the global namespace. It
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This pattern allows for different connections to be passed to different objects:
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also implies that you can only ever use a single connection.
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## Multiple Redis connections
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However, the single connection pattern facilitates only those cases where you
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connect to a single Redis instance, and where you affect global context (by
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replacing the existing connection with the `use_connection()` call). You can
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only use this pattern when you are in full control of your web stack.
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In any other situation, or when you want to use multiple connections, you
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should use `Connection` contexts or pass connections around explicitly.
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### Explicit connections (precise, but tedious)
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Each RQ object instance (queues, workers, jobs) has a `connection` keyword
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argument that can be passed to the constructor. Using this, you don't need to
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use `use_connection()`. Instead, you can create your queues like this:
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```python
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```python
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from rq import Queue
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from rq import Queue
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@ -73,11 +32,19 @@ q2 = Queue('bar', connection=conn2)
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Every job that is enqueued on a queue will know what connection it belongs to.
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Every job that is enqueued on a queue will know what connection it belongs to.
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The same goes for the workers.
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The same goes for the workers.
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This approach is very precise, but rather verbose, and therefore, tedious.
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### Connection contexts (precise and concise)
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### Connection contexts (precise and concise)
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<div class="warning">
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<img style="float: right; margin-right: -60px; margin-top: -38px" src="/img/warning.png" />
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|
|
|
|
|
|
<strong>Note:</strong>
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|
|
|
|
|
|
<p>
|
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|
|
|
|
|
|
The use of <code>Connection</code> context manager is deprecated.
|
|
|
|
|
|
|
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Please don't use <code>Connection</code> in your scripts.
|
|
|
|
|
|
|
|
Instead, use explicit connection management.
|
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|
|
|
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|
|
</p>
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</div>
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There is a better approach if you want to use multiple connections, though.
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There is a better approach if you want to use multiple connections, though.
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Each RQ object instance, upon creation, will use the topmost Redis connection
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Each RQ object instance, upon creation, will use the topmost Redis connection
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on the RQ connection stack, which is a mechanism to temporarily replace the
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on the RQ connection stack, which is a mechanism to temporarily replace the
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