Ambiguous error codes: 3, 5, 21, 26, 47 etc. What are they?

[evscott]

Hi everyone, I am investigating intermittent failures in a Django application when performing cache operations during Celery task execution which only emit error codes that don't seem to be documented. Would someone please clarify what these error codes mean? Is there some logical mapping of them to libmemcached errors?

Others have reported confusion about these error codes which supports my belief that they are not (clearly) documented anywhere. Clarifying this would be very helpful for users of this package.

Here are some examples of the error codes and cache operations:

error 3 from memcached_get
error 15 from memcached_get
error 15 from memcached_delete
error 21 from memcached_set
error 26 from memcached_get
error 47 from memcached_set

These are the package versions I'm using:

django = 1.11.29
pylibmc = 1.6.3
libmemcached = 1.1.4-1
celery = 4.4.7

And this is my Django cache configuration, note that I am using a single cache host that's in a Docker container on the same machine as my Django application:

MEMCACHED_HOST = os.environ.get('MEMCACHED_HOST', 'memcached')
CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.PyLibMCCache',
        'LOCATION': '{}:11211'.format(MEMCACHED_HOST),
    }
}

[evscott]

Here are some related issues where other people report similar confusion about these error code:

1. memcached error 21 memcached/memcached#114
2. Memcache error ContactEngineering/topobank#737
3. error 47 from memcached_set : (0x337cb10) SERVER HAS FAILED AND IS DISABLED UNTIL TIMED RETRY, host: 127.0.0.1:11211 zulip/zulip#14805

[lericson]

Interesting. I guess it’s because 1.1.x is newer than what we build against. In fact I thought libmemcached was basically stalled but I guess not!- LudvigOn 16 Dec 2024, at 17:00, Eliot V Scott ***@***.***> wrote: Here are some related issues where other people report similar confusion about these error code: memcached/memcached#114 ContactEngineering/topobank#737 zulip/zulip#14805 —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[evscott]

Oh, interesting. Will you be looking into how this builds against 1.1.x in that case? Do you recommend using a specific, older version of libmemcached?