[Seaside] Re: static image files

[David Shaffer]

Jimmie Houchin wrote:

>
> Hello,
>
> Let me see if I understand correctly here.
>
> Squeak's file I/O blocks, so any activity which requires file access
> impacts the performance.

Yes.  Of course the real impact depends a lot on application usage
patterns (is it the same image file being served many times to the same
user?  a bunch of different users?  a bunch a different image files?). 
It also depends on how well browser caching is working or if you're
using a front-end cache (like squid) how well it is working.

>
> What about the network I/O? Is it non-blocking?

Yes, network I/O is non-blocking (the Squeak UNIX VM has a polling-based
custom asynchronous I/O model).

>
> Are there any significant problems when a request requires some
> time-consuming action before returning? Such as calling other servers
> web services. Does it negatively impact other requests?

If the operation is in squeak and is CPU intensive fork it off at a
lower priority and have the request thread wait on a semaphore for the
compute intensive process to complete.  Calling web services would take
advantage of the non-blocking socket I/O calls.

>
>
> Thanks for any wisdom or insight.

:-) I hope that it turns out to be helpful. :-)

David