Add Django cache identification to Redis client metadata

[Vasil Chomakov]

Proposal: Add Django cache identification to Redis client metadata

Context

Redis documentation recommends that clients identify themselves via connection metadata to help operators monitor, debug, and reason about production systems (for example using CLIENT SETINFO / CLIENT INFO):

​https://redis.io/docs/latest/commands/client-setinfo/

This information is intended to help Redis operators understand what software is connecting to their servers, especially in shared or multi-tenant environments.

Django’s Redis cache backend is built on top of redis-py, which means Redis connections created by Django are currently indistinguishable from other redis-py-based clients in shared Redis deployments. This makes it harder for Redis operators to attribute traffic, diagnose issues, or understand cache usage patterns when multiple applications or frameworks share the same Redis instance.

Proposal

Django could provide additional, non-invasive client identification for Redis cache connections to indicate that the connection originates from Django’s cache framework.

redis-py exposes a driver_info API that may be used to attach Django-specific context to the connection, in line with Redis’s client identification recommendations.

Goals

• Align with Redis client identification best practices
• Allow Redis operators to distinguish Django cache connections
• Improve observability in shared Redis environments

Example (illustrative)

A Redis connection created by Django’s cache backend might expose metadata equivalent to:

• Client library: redis-py
• Framework: django-cache

Scope

• This is a feature proposal, not a patch submission
• No behavioral changes to caching semantics are proposed
• Any implementation would rely solely on redis-py’s supported APIs

[ar3ph]

I poked around and got a working solution. Although in future versions of redis-py, lib_name and lib_version are ​deprecated, DriverInfo is not available for latest redis-py release v7.1.0.

In django/core/cache/backends/redis.py:

class RedisCacheClient:
    def _get_connection_class(self, lib):
        class DjangoConnection(lib.Connection):
            def __init__(self, *args, **kwargs):
                super().__init__(*args, **kwargs)
                self.lib_name = "django"
                self.lib_version = django.get_version()

        return DjangoConnection
   def __init__(
        servers,
        serializer=None,
        pool_class=None,
        parser_class=None,
        **options,
    ):
    ...
    
    self._connection_class = self._get_connection_class(self._lib)
    ...
    self._pool_options = {
            "parser_class": parser_class,
            "connection_class": self._connection_class,
            **options,
        }

I can make a PR once this ticket is accepted. And we'll have to update again once DriverInfo for redis-py is released.

[ar3ph]

or I can make it default to use driver_info when lib_name and lib_ver are no longer supported.

[Vasil Chomakov]

I suggest using DriverInfo when available (can be successfully imported) and falling back to lib_name and lib_version if redis-py does not yet support it.

IMPORTANT: Note that when manually set, lib_name and lib_version should look like this:

• lib_name = redis-py(django-cache_v{django-cache-version})
• lib_version = {redis-py-version}

per Redis CLIENT SETINFO documentation: ​https://redis.io/docs/latest/commands/client-setinfo/

[ar3ph]

Here is a django-redis ​example. Perhaps the best solution is to just change the lib-name to include our upstream driver.

The lib-name will become like redis-py(django_v6.1.0)

[ar3ph]

Replying to Vasil Chomakov:

I suggest using DriverInfo when available (can be successfully imported) and falling back to lib_name and lib_version if redis-py does not yet support it.

IMPORTANT: Note that when manually set, lib_name and lib_version should look like this:

• lib_name = redis-py(django-cache_v{django-cache-version})
• lib_version = {redis-py-version}

per Redis CLIENT SETINFO documentation: ​https://redis.io/docs/latest/commands/client-setinfo/

Should the driver be called django-cache? My opinion is to just call it django, b/c django-cache is not a separated package.

[Vasil Chomakov]

I agree, django_v{django-version} is descriptive enough.
So when using DriverInfo, just setting the upstream driver to django_v6.1.0 would suffice.
When DriverInfo is not available:

• lib_name = redis-py(django_v6.1.0)
• lib_version = {redis-py-version}

[ar3ph]

Replying to Vasil Chomakov:

I agree, django_v{django-version} is descriptive enough.
So when using DriverInfo, just setting the upstream driver to django_v6.1.0 would suffice.
When DriverInfo is not available:

• lib_name = redis-py(django_v6.1.0)
• lib_version = {redis-py-version}

I finished this in the proposed ​PR. Note that lib_version defaults to redis-py version. So nothing for us to do there.

[Jacob Walls]

The request makes sense, but I'm not sure we've identified the least invasive solution.

[ar3ph]

Thanks. I'll look into the implementation.

[ar3ph]

I've updated my ​PR to avoid dynamic class creation, only changing the pool_options now as a better alternative.

[Jacob Walls <jacobtylerwalls@…>]

In 72ae25a:

Fixed #36879 -- Identified Django client in Redis client metadata.