Hi Perrin, On Tuesday, November 26, 2002, at 06:14 PM, Perrin Harkins wrote:
I don't want to use a database table for the sole purpose of sharing data, I mean, I run the Apache/mod_perl servers to handle different components of our system, some run on top of a database and some of them don't.Bas A.Schulte wrote:none ofWhat are you trying to share? In addition to Rob's suggestion of using a database table (usually the best for important data or clustered machines) there are other approaches like IPC::MM and MLDBM::Sync.
them seemed to be stable/fast under heavy load even though I would have preferred that as it would allow me to do something to handle data-sharing between children via the parent which always seems to be in issue in Apache/mod_perl.
Also, the things I would want to share are fairly dynamic things so a roundtrip to a database would probably add quite some overhead.
I have been looking at some of the IPC::Share* modules, the one I think I can use is (not sure here) IPC::ShareLite, but that darned thing won't install on my dev. machine (iBook/OS X) so I've been postponing things a bit ;)
My current plan is IPC::MM, stay tuned.
As to *what* I'm trying to share: I don't really know yet ;) Dynamic stuff like:
- what is a given child doing (to do things like: ok, I'm currently pushing data to some client in 5 children, and I don't want to have another child do this now so stuff this task in a queue somehere so I can process it later);
- application state. This is domain-specific so it's a bit hard to explain what I mean. I need serialized and *fast* access to this info so I would prefer not having this in my database.
NB: I posted a question on the first issue (look for "IPC suggestions sought/talking between children?" somewhere in the mod_perl mailinglist, I never seem to recall the proper archive site for it), didn't get any feedback on it as it probably goes beyond what someone would normally want from a web server.
Again; I don't know exactly but when I read stuff about entity-, session- and message beans, JMS etc., it has a lot of resemblance with what I'm currently doing "by hand" i.e. implement functionality like that on top of a "bare" Apache/mod_perl server.BTW: I've been reading up a lot on J2EE lately and it appears more and more that a J2EE app server could quite nicely provide for my needs (despite all shortcomings and issues of course).
What is it that you think you'd be getting that you don't have now?
A good example would be JMS: you get this "for free" (with JBoss anyway ;)) in a J2EE app. server but there's no obvious choice for us perl guys. There are some options I see now and then: Spread/Stem/POE, but none of these choices are obvious in the sense that they are being used by a lot of people to solve the type of problems JMS solves so there's really no one to turn to for advise; again, I'm building stuff between the raw metal and my own stuff.
BTW: with the issue on data-sharing: the same thing: I have raw metal (Apache/mod_perl and IPC:MM) and need to implement an API on top of them before I have the needed functionality. Again I'm building stuff again before I can solve my actual business problems.
I think these issues point out that we are missing *something*, I know *I* am :)
Regards,
Bas.
