This is a bug affecting Quay logs.

The following exception is logged as DEBUG:

gcworker stdout | 2023-03-16 12:43:26,056 [86] [DEBUG] [util.locking] Could not connect to Redis for lock REPO_GARBAGE_COLLECTION_452: You can't write against a read only replica. 

The above exception is logged whenever Quay is unable to acquire a lock inside Redis.

This message should be logged as WARNING or ERROR because if Quay is not able to acquire a lock inside Redis, the garbage collector will not work.
The exception should be logged with a higher log level.