Jelte Fennema-Nio

Now that https://github.com/citusdata/citus/pull/6281 is merged which fixed https://github.com/citusdata/citus-enterprise/issues/284 we can merge this one too.

> Should we do this for splits as well? I'm having a refactoring PR almost ready on top of this that will share more code including this with splits.

> Also, sounds like a good idea to add a single test -- if we do not have any -- just in case Citus hits some weird edge case of...

> Do you have any data points to share, like with this schema & data size, each shard move time decreased from X -> Y on your local machine? Sadly...

A blog post with a similar issue and solution can be found here: http://robertolopes.me/2015/07/operationtimedout-exception-raised-when-using-the-cassandra-driver-for-python-in-conjunction-with-celery-delayed-tasks/ And sometimes tests are failing for us because of this: https://travis-ci.org/JelteF/Stream-Framework/jobs/168539883

Thanks for the explaination. I [forked shlex](https://github.com/GetStream/go-shlex/) to support Go escape sequences as well as it's regular escapes. I'm trying it out now on my own project and it seems...

Having a delete and/or rename option would be very useful. I created a cert with a bit of a bad name, but there's no clear way to remove it or...

I think the code in the PR is fine now (apart from the merge conflict that occured due to another merged PR). But after playing with these changes a bit...

> Is there a reason why `active_cancel` is singular and `wait_cancels` is plural? Could that be more consistent? Yes, `active_cancel` is a server connection on which **a single** active cancelation...

There can be more than one server in the `active_cancel` state, but each of those server connections is only forwarding a single cancel request.