Can somebody give me an advice about what to learn?

[Chris Angelico]

On Mon, Oct 1, 2012 at 12:23 AM, Roy Smith <roy at panix.com> wrote:
> In article <mailman.1672.1349011558.27098.python-list at python.org>,
>  Chris Angelico <rosuav at gmail.com> wrote:
>
>> there's no efficient and reliable way to change/reload code in a
>> running application (not often an issue).
>
> What we do (largely cribbed from django's runserver) is start up a
> thread which once a second, looks at all the modules in sys.modules,
> checks to see if the modification time for their source files has
> changed, and if so, restarts the application.  This is hugely convenient
> when developing any kind of long-running application.  You don't need to
> keep restarting the application; just edit the source and changes take
> effect (almost) immediately.
>
> Not sure if this is what you had in mind.

It's not an _explicit_ restart, but you have to write your application
to keep all its state on disk in some way. What I'm talking about is
having a single process that never terminates, never stops accepting
connections, but at some point new connections begin to be served with
new code - with old ones, if they're still going, continuing to be
handled by the old code. I have one such process that's been going for
(let me check) 115 wk 0d 21:05:21.

For many types of application, restarting is perfectly viable, so this
isn't a major issue with Python.

ChrisA