Issue 1:
Checklist

I have verified that the issue exists against the master branch of Celery.

This has already been asked to the discussion group first.

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have included the output of celery -A proj report in the issue.

(if you are not able to do this, then at least specify the Celery

version affected).

I have verified that the issue exists against the master branch of Celery.

I have included the contents of pip freeze in the issue.

I have included all the versions of all the external dependencies required

to reproduce this bug.

Optional Debugging Information

I have tried reproducing the issue on more than one Python version

and/or implementation.

I have tried reproducing the issue on more than one message broker and/or

result backend.

I have tried reproducing the issue on more than one version of the message

broker and/or result backend.

I have tried reproducing the issue on more than one operating system.

I have tried reproducing the issue on more than one workers pool.

I have tried reproducing the issue with autoscaling, retries,

ETA/Countdown & rate limits disabled.

I have tried reproducing the issue after downgrading

and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

In #5661 PR result encoding was removed from _store_result call.

In #5918 PR missing result encoding on storing has been attempted to be resolved by adding encode call on decode call.

Possible Duplicates

None

Environment & Settings

Celery version:

celery report Output:

Steps to Reproduce

Required Dependencies

Minimal Python Version: N/A or Unknown

Minimal Celery Version: N/A or Unknown

Minimal Kombu Version: N/A or Unknown

Minimal Broker Version: N/A or Unknown

Minimal Result Backend Version: N/A or Unknown

Minimal OS and/or Kernel Version: N/A or Unknown

Minimal Broker Client Version: N/A or Unknown

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

Other Dependencies

N/A

Minimally Reproducible Test Case

Expected Behavior

store_result uses serializer.

Actual Behavior

store_result ignores serializer, so getting serialization errors for data types that are compatible with chosen serializer.

For more details please refer to tests in #6259

Issue 2:
Hello all

We use Celery 3.0.21 with Redis backend (AWS ElastiCache) and recently I discovered huge memory usage by Redis node. After dumping Redis database and inspecting it I found that there are many reply pidboxes (~40) with 1 big element in array (about 16MB) in which there are many duplicated scheduled tasks (more than thousand).

I think duplicated tasks is a different issue connected with visibility timeout. So could anybody clarify approach to delete unused reply pidboxes? I've checked number of reply pidboxes with members of _kombu.binding.reply.celery.pidbox hash and found inconsistency (41 in bindings versus 77 at all).

And I would much appreciate it if anybody explaine case when these orphaned pidboxes could appear.