MaxConnectionsError not used consistently

[PeterJCLaw]

Version: redis-py 5.0.4
Platform: Ubuntu 22.04

The docs around the max_connections argument in various places suggest that MaxConnectionsError should be used to indicate a lack of available connections, yet that exception type seems only to be used in one place:

redis-py/redis/asyncio/cluster.py

Line 1051 in 6751de2

raise MaxConnectionsError()

Other places use ConnectionError("Too many connections").

Is this expected? Should these all use MaxConnectionsError?

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[PeterJCLaw]

This looks like it's mostly been resolved (as part of addressing #3684), though there's still one place where it's not:

redis-py/redis/asyncio/connection.py

Line 1211 in 440465b

raise ConnectionError("Too many connections") from None

Perhaps this was just an oversight?

cc @petyaslavova as someone who may have context.

I'd be happy to have a go at putting up a PR to change over if that's useful.

[petyaslavova]

Hi @PeterJCLaw, if you have some time to add this fix this it will be great :) I will review it ASAP.
The MaxConnectionsError is a subclass of ConnectionError, so it won't be a breaking change and we will be able to release it as part of a minor version release.

[PeterJCLaw]

@petyaslavova thanks, I've raised #3859.