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Comment by schemescape | Hacker News Reader

Which Common Lisp implementation do you use? If it’s SBCL, has memory usage been a problem? Edit: I see SBCL in one of your Makefiles.

I use a VPS with 512 MB of RAM, but each SBCL instance uses roughly 100 MB of RAM, so I can only have a couple services at once.

I’ve considered moving the lowest traffic services to CLISP, but it’s missing at least one feature I use (package—local nicknames).

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SBCL needs a relatively large amount of memory to start with, but beyond that it doesn't require much. I run a few small services written in Common Lisp. Instead of running a separate process for every one of them I run a single SBCL process and run each service in a different thread.

This has some downsides: Firstly they run in the same address space, so global state is shared and serious bugs can affect another service. Secondly they run as a single systemd service, so they're not easy to manage individually. Still I've found it to work quite nicely for things that are simple and don't really need attention.

Thanks! That setup is actually my backup plan if I start to run out of memory.

Maybe it’s my imagination but it seems like CL isn’t as suited to sharing code and read-only data pages across processes (e.g. in shared libraries). Or maybe there’s a solution I just haven’t found yet…

Yes, I use SBCL. For static websites, the memory usage is not a problem because SBCL exits after generating the website.

For long running services, it does consume about 100 MB of memory. For example, I have a service running right now with an uptime of 270 days. SBCL is currently consuming 108 MB of memory. This has not been a problem either because for low traffic websites like mine, this memory consumption size remains fairly stable. I have not found it to be varying much.

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