[pro] How to interact with a running lisp instance?

[David Owen]

On Fri, 17 Dec 2010, Ryan Davis wrote:

> While having a long-running process on the server is appealing, we
> decided to spend our engineering time on making the lisp process
> easy to start, stop, restart, and deploy.

I agree, very valuable.  More so than live updating.

> Personally, doing a lot of direct patching to a production system
> scares me.  I worry about introducing bugs/hidden dependencies that
> wouldn't be represented in source code, and getting conflicts
> between multiple developers updating the same lisp.

One thing I do is rebuild the image from scratch, then test that (on a
different port or system, maybe).  If everything checks out, *and* I
want to update without downtime (because it's only on 1 system for
example), *then* I attach to the existing process and load up the new
stuff.

If something goes wrong, well, I now have downtime anyway, but have
the clean image available for a restart.  But if everything appears
fine, I might schedule a restart for some future time anyway.

So, there's a nice continuum to find a solution to fit your needs.

-David