*** Bug 1768268 has been marked as a duplicate of this bug. ***

Hackish fix:

#Remove tornado package
sudo rpm -e --nodeps python3-tornado

#install last supported tornado version from python repos
sudo pip3 install tornado==5.1.1

#salt-minion doesn't find them outside of managed paths, so links needed.
ln -s /usr/local/lib64/python3.7/site-packages/tornado /usr/lib64/python3.7/site-packages
ln -s /usr/local/lib64/python3.7/site-packages/tornado-5.1.1-py3.7.egg-info /usr/lib64/python3.7/site-packages

(In reply to Jason Elwell from comment #2)

I have downloaded salt-2018.3 and old tornado src.rpm from koji, recompiled and installed.

(In reply to Jason Elwell from comment #2)
> Hackish fix:
> 
> [snip]

Jason's hackish fix is working fine for me with Fedora 31 salt minions and a Fedora 28 salt master.

Thanks!

Afaik Tornado 5 support in Salt is still an ongoing task. You should pick the latest 4.x release if possible.
https://github.com/saltstack/salt/issues/51883

(In reply to Jochen Breuer from comment #5)
> Afaik Tornado 5 support in Salt is still an ongoing task. You should pick
> the latest 4.x release if possible.
> https://github.com/saltstack/salt/issues/51883

Jochen, It looks like you're absolutely right.  Tornado less than 5.0 is the requirement for 2019.2.1, looking at that branch's docs:
https://github.com/saltstack/salt/blob/2019.2.1/requirements/static/fedora-30.in

However, looking at my F30 install, the version is:
python3-tornado-5.0.2-5.fc30.x86_64
Which may not mean much if care wasn't taken, since salt may go the way of upstart.  

I'm currently not seeing any errors logged with the 5.1.1 version.  However since that is the supported tornado version to run salt...

#hackish fix, to install 4.5.3:
sudo rpm -e --nodeps python3-tornado
sudo pip3 install tornado==4.5.3
sudo ln -s /usr/local/lib64/python3.7/site-packages/tornado /usr/lib64/python3.7/site-packages
sudo ln -s /usr/local/lib64/python3.7/site-packages/tornado-4.5.3-py3.7.egg-info /usr/lib64/python3.7/site-packages

#downgrade to 4.5.3, if you'd implemented my previous hackish fix:
sudo pip3 install tornado==4.5.3
sudo ln -s /usr/local/lib64/python3.7/site-packages/tornado-4.5.3-py3.7.egg-info /usr/lib64/python3.7/site-packages
sudo unlink /usr/lib64/python3.7/site-packages/tornado-5.1.1-py3.7.egg-info

The issue in the initial report is fixed in salt 3000 which is packaged for Fedora 30+, so this bug can be closed.

To undo my hackish fix for Fedora 31 and set things back to rights, you may want to do the following.  This will not happen on it's own.  


###Check an be sure to see the hackish changes are still there

$ rpm -q python3-tornado
package python3-tornado is not installed

#if this returns 5.1.1, change the paths for removal, if this returns 6, STOP!  you didn't apply my fix
$ pip3 freeze |grep tornado
tornado==4.5.3

$ file /usr/lib64/python3.7/site-packages/tornado*
/usr/lib64/python3.7/site-packages/tornado:                      symbolic link to /usr/local/lib64/python3.7/site-packages/tornado
/usr/lib64/python3.7/site-packages/tornado-4.5.3-py3.7.egg-info: symbolic link to /usr/local/lib64/python3.7/site-packages/tornado-4.5.3-py3.7.egg-info



###If you have double checked the output matches the info above, remove the old tornado package (without pip)

$ sudo rm /usr/lib64/python3.7/site-packages/tornado 
$ sudo rm /usr/lib64/python3.7/site-packages/tornado-4.5.3-py3.7.egg-info
$ sudo rm -R /usr/local/lib64/python3.7/site-packages/tornado 
$ sudo rm -R /usr/local/lib64/python3.7/site-packages/tornado-4.5.3-py3.7.egg-info 

#confirm the package is gone, this should return nothing
$ pip3 freeze |grep tornado

#install the Fedora provided tornado package
$ sudo dnf -y install python3-tornado

#restart the service
$ sudo systemctl restart salt-master
$ sudo systemctl restart salt-minion

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