Settings¶

All settings live in one dictionary:

DJANGO_CELERY_RESULTS_REDIS = {
    "DRIVER": "indexed",
    "URL": "redis://localhost:6379/0",
}

Key	Default	Description
`DRIVER`	`"indexed"`	`"raw"`, `"indexed"`, `"redis_om"`, or the dotted path of a `Store` subclass. See drivers.
`URL`	`"redis://localhost:6379/0"`	Passed to `redis.Redis.from_url()`. A `sentinel://host:port;sentinel://host:port/0` URL (the format Celery uses) connects through Redis Sentinel and follows the current master.
`CLIENT_KWARGS`	`{}`	Extra keyword arguments for `redis.Redis.from_url()`. `decode_responses` is always `True`.
`CLIENT_FACTORY`	`None`	Dotted path of a callable returning a `redis.Redis` client created with `decode_responses=True`. Takes precedence over `URL` (Sentinel, custom pools, ...).
`KEY_PREFIX`	`"dcrr"`	Prefix of every key the package writes. Must not contain `:`, `*`, `?`, `[`, `]` or whitespace.
`ALLOW_EDITS`	`False`	Makes the admin change form editable. Falls back to `DJANGO_CELERY_RESULTS["ALLOW_EDITS"]`.
`TASK_ID_MAX_LENGTH`	`255`	`max_length` of `task_id`, `task_name` and `group_id`. Falls back to `DJANGO_CELERY_RESULTS_TASK_ID_MAX_LENGTH`. Read when models are loaded.
`SCAN_COUNT`	`1000`	`COUNT` hint for `SCAN`.
`BATCH_SIZE`	`500`	Number of records fetched, deleted or indexed per round trip.
`RESULT_TTL`	`None`	Seconds, or a `timedelta`. Sets a TTL on result and group keys on every write. `raw` and `redis_om` only.
`ID_FIRST_URLS`	`False`	Also register the deprecated `<task_id>/done/` style URLs. The original package defaults to `True`.
`SEARCH`	`None`	`"redisearch"` builds a trigram index so that the admin search and `icontains` lookups are answered by RediSearch instead of reading every record. Needs RediSearch and database 0. See drivers.
`SEARCH_MAX_TEXT`	`4096`	Values longer than this are not tokenized; searches on them read the record instead.
`SEARCH_MAX_CANDIDATES`	`50000`	When a search term matches more records than this, the index is skipped and every record is read.
`SENTINEL_MASTER_NAME`	`"mymaster"`	Master name used with a `sentinel://` URL.
`SENTINEL_KWARGS`	`{}`	Extra keyword arguments for the sentinel connections (passwords, TLS, ...).

Settings are read lazily, so django.test.override_settings works, and changing the setting drops the cached client and store instances.

Celery¶

# settings.py
CELERY_RESULT_BACKEND = "django-redis-db"

django-redis-db is registered in the celery.result_backends entry point group. The class path works too: "django_celery_results_redis.backends:RedisResultBackend". The backend reads its connection from DJANGO_CELERY_RESULTS_REDIS; anything after the alias in the result backend URL is ignored.

Celery options that the backend honours, exactly like the database backend: result_extended, result_expires, result_chord_join_timeout, result_backend_always_retry (retries on Redis connection and timeout errors), task_track_started.

System checks¶

Id	Level	Condition
`django_celery_results_redis.E001`	error	Unknown `DRIVER`, or a dotted path that is not a `Store` subclass.
`django_celery_results_redis.E002`	error	`DRIVER` is `redis_om` but `redis-om` is not installed.
`django_celery_results_redis.E003`	error	RediSearch is in use (`redis_om` driver or `SEARCH`) and `URL` selects a database other than 0.
`django_celery_results_redis.E004`	error	Invalid `KEY_PREFIX`.
`django_celery_results_redis.E005`	error	`ALLOW_EDITS` is not a boolean.
`django_celery_results_redis.E006`	error	`RESULT_TTL` is set with the `indexed` driver, or is not a positive number of seconds.
`django_celery_results_redis.E007`	error	`SEARCH` is neither `None` nor `"redisearch"`.
`django_celery_results_redis.E101`	error	Redis is unreachable.
`django_celery_results_redis.E102`	error	RediSearch is in use but the server does not have it.
`django_celery_results_redis.E103`	error	Redis server older than 7.0.
`django_celery_results_redis.W101`	warning	`maxmemory-policy` evicts arbitrary keys (`allkeys-*`), which can drop results and desynchronise indexes.

E1xx/W1xx connect to Redis, so they are registered under the database tag and only run with manage.py check --database default.

Management commands¶

Command	Purpose
`celery_results_redis_import`	Copy results from the django-celery-results tables into Redis. See the migration guide.
`celery_results_redis_rebuild_index`	Rebuild the driver's indexes and the search index from the stored records. Run it after switching drivers or enabling `SEARCH`.

Storage format¶

The records under a key prefix carry a format version, kept in <prefix>:meta. A release that writes a different format refuses to read the data and says so, rather than returning wrong results. To move to such a release, let the old results expire, delete them, or point KEY_PREFIX somewhere else.

Redis Cluster¶

Not supported. Celery's own Redis result backend does not support cluster mode either. The Lua scripts and the index operations address several keys at once, which a cluster would have to have in the same slot.