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Graceful server restart
Python Other
Branch: master
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bin grace start command works in the simplest case now
grace Add wait command
.gitignore Add more examples of endpoints Stole better travis runner from pypy branch
.travis.yml Undo last commit -- wrong project
Makefile Add tac template and

Graceful swan takes flight. Hunter eyes his prey. KABLAM! Hunter falls. Swan holsters gun. Server continues running.

grace lets you restart your server without interrupting current users. It's a runtime configurable, port forwarder.

Build Status


Install the dependencies:

pip install Twisted
pip install PyOpenSSL # if you want SSL support

Either clone repo:

git clone grace.git
cd grace.git

Or download a tar:

tar xf master
cd iffy-grace-*

Then install:

python install


Start forwarding TCP traffic from port 9000 to port 7500 on the local machine:

grace start tcp:9000 tcp:host=

Switch traffic from port 7500 to port 7600 (without disconnecting anyone still connected to port 7500):

grace switch tcp:9000 tcp:host=

List forwarding rules:

grace ls

Wait for previous forwards to finish:

grace wait

Stop forwarding:

grace stop

It's not just for HTTP

Because grace uses Twisted's excellent endpoints, you can forward just about any traffic to just about anywhere. Here's SSL to TCP:

grace start ssl:443:privateKey=key.pem:certKey=crt.pem tcp:host=


grace start tcp:9000

TCP to domain socket:

grace start tcp:9000 unix:/var/foo/bar

Domain socket to TCP:

grace start unix:/var/foo/bar tcp:host=

Planned usage not yet supported

Upgrade grace to a new version and swap out the current grace process with a new one:

grace restart

Specify where logs, pid and control socket go (XXX needs more explanation):

grace -d /tmp/foo start tcp:9000 tcp:host=

Running the tests

Use trial to run the tests:

trial grace
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