Forum OpenACS Q&A: mod_aolserver: make a wish

Posted by Petru Paler on

I'm going to try and continue the mod_aolserver development (mainly porting it to Apache 2.0 but also adding features and removing bugs). For this I need people to tell me what problems they had with setting it up, and what features they would like to see implemented, so those who are interested, please speak up

Posted by Don Baccus on
Hey, that's great, Petru ... should we host it here as a project at, with you as owner?
Posted by finn knudsen on
Hi Petru

Great idear. I started out using the mod_aolserver on apache because I had some old perl scripts I wanted to keep using. But I have since switched over to using Aolserver instead. I must say though, that I probably will not switch back now, but I think many people would be interested in at least trying openacs out, if they could use the webserver they are used to.

I personally downloaded the RPM's and got mod_aolserver running after a bit of problems. You can see a discussion I had with Michael here about some installation problems on RedHat 7.0

He never got back to me about the installation guide but I have a rough draft I can send you.

Another good person to contact might be Os Tyler, you can find him through the thread below. It seems he has been working quite a bit with mod_aolserver

Okay, a short list of things I would think could be important :

Getting the RPM's up to date with the new release of redhat, so they will install without a problem.

There where some problems with the abstract urls. Os tyler has posted a solution here sometime.

I had problems with the create neighborhood module. In general it was with the forms module generator, and there is some postings here.
I personally have a feeling that it may be something with the redirect/heades that doesn't work properly in mod_aolserver, rather than the actual tcl code.

There where generally quite a few problems, but they could just as well be caused by my lack of understanding of openacs. The aol server I'm running now arent working 100 % either.

However, there are one thing that I found would be extremely important and usefull. If it where possible to use mod_aolserver alongside mod_perl, mod_php etc. it would be much easier to migrate and existing site to openacs. I tried to contact various people to see if they had it running, but I couldn't find anyone that had actually gotten it working. I could be problems with the apache configuration but I gave up on getting it working. ( Part of the reason why I switched to Aolserver ).
I could get apache to execute the cgi scrips to execute but the would die.

Anyway , I thinks its a great initiative, and I will try to help if I can. However, I don't have an apache server running at the moment, so I can't do much actual testing.

Feel free to write anyway, if you think I can help.

Posted by Petru Paler on

  • Don: yes, having a central project (and public CVS repository) would be useful.
  • Finn: thanks for your notes!
Posted by Don Baccus on
Petru and I are working to set this up on the  News at 11  (or on May 11th, something like that!)
Posted by Roberto Mello on
I am wrapping up the documentation for 3.2.5. Where should I point the link to mod_aolserver now that is dead? Will it be hosted here or over at
Posted by Don Baccus on
mod_aolserver is really an ACS-ish thing, I doubt if most opennsd users want to use it.  They'll just use opennsd (as will I)!

mod_nsd is in CVS right now as the project mod_nsd.  I've just not entered it into the SDM yet.  Bug me tomorrow if I don't get to it, OK?

Posted by Steve Peterson on
It'd sure be nice if virtual hosting were easy to use.
Please see my related thread.
Posted by Os Tyler on
Hi Petru.

Good luck in your endeavor. I am glad someone will continue the development of mod_aolserver.

You asked me about changes to be made for mod_aolserver.

I am currently running apache 1.3.19 and openacs 3.2.4, postgres7.0, mod_aolserver1.1.

One question I have is about compatibility with openacs4.x or acs4.x will mod_aolserver continue to work just the same for 4.x?

A positive note, I am able to run 1 instance of openacs as a virtual host as well as multiple "ordinary" virtual hosts. So it seems that mod_aolserver does not affect virtual hosting. (I'm posting to: after sending this)

I have not yet done a lot of experimentation, but I can give you a short list.

I don't know if it is a specific issue with mod_aolserver, but the two things I have noticed are problems with displaying images. (And it does seem that people not using mod_aolserver do not have the same problems.)

First there is a problem with displaying local images, such as those in acsroot/doc/prototype.html

In acsroot/parameters/server.ini, if I set:
ns_param EnableAbstractURLsP 1

the images do not appear, just broken links.

Then I set:
ns_param EnableAbstractURLsP 0

and restart the apache, the images appear.

The second problem is with "remote" images (img src=http://somwhere-else)

For instance, in the chat module the image:
appears fine when I first load the page.

When I type some text and click submit, the image does not appear, but shows a broken link.

This occurs regardless of the setting of EnableAbstractURLsP.

Hope that's helpful,


Posted by Petru Paler on

Os: right now mod_aolsever (which has been renamed to mod_nsd in the mean time :) will not boot ACS4.x (haven't tried OpenACS 4.x yet) because of missing modules (nscache, nssha1, etc) and probably also other bugs. I'm working on a quick and dirty emulation on Tcl so people can use it if they have to, then I will do the proper thing in C (probably when porting to Apache 2.0).

Posted by Os Tyler on
I see that mod_nsd has a place in the SDM. Thank you Ben!

Petru, I have a question, and another apparent bug in mod_aolserver1.1.

Let me first say that I'm continuing to post here because as far as I know this is the best place to post mod_aolserver / mod_nsd information at present. If I'm wrong about that, please let me know. Does mod_nsd merit it's own message board to save disinterested people the trouble of hearing about it?

Now that mod_aolserver is called mod_nsd, is there a difference in code yet, or just in name? (Should I be using mod_nsd instead of mod_aolserver?)

I have just discovered an interesting "side-effect" to running mod_aolserver1.1.

Running mod_aolserver breaks CGI (on my machine, anyway)

Here are the details.

I'm testing with a very simple CGI, a shell script that simply prints the Content Headers and echos some text.

The CGI works fine when I add to httpd.conf:
LoadModule aolserver_module  libexec/

But as soon as I add:
AddModule mod_aolserver.c
AolServerConf config_file /web/conf/mod_aolserver.tcl

The CGI generates the standard errors:
HTTP/1.1 500 Internal Server Error (in the HTML HEADER)
Premature end of script headers: /web/cgi-bin/test-cgi (in the error_log)

I'm running Apache_1.3.19, php4.0.4 (dso), mod_aolserver1.1 (dso) ... everything else is compiled into httpd.

Thanks for any suggestions,


Posted by Petru Paler on

Thanks for the bug report, I'll try to reproduce it in here. Could you please email me the script at

There are some differences between the CVS tree and the last mod_aolserver release (mainly DB drivers updates), but stick with mod_aolserver until I make a release of mod_nsd (which should be quite soon).

Regarding a new forum: I think it's a matter of how many people are interested and how much traffic this will generate. If needed, I guess it's not a big deal to add a new forum...

Posted by Steve Peterson on
Just wanted to add a little more info to the mod_aolserver/mod_cgi bug.  Os Tyler asked me to run a test to see if the same error occurred on my system.  It does.  I'm probably using a completely different cgi script that Os.

What I want to add is that it doesn't matter whether I'm running the CGI under the virtual host that has mod_aolserver configured or another virtual host that does not.  The result is the same.  Note that I dont have mod_aolserver configured under the main server in the apache.conf file.  See related thread

Even though this is just as much an issue about how Apache 1.3.x doesn't isolate module interaction in virtual hosts as it is a mod_aolserver issue, at this point I'm going to have to abandon mod_aolserver.  I'd  recommend that until mod_nsd is ready that anyone who needs to run mod_cgi in the same instance of Apache as OpenACS, that instead they run AolServer/OpenNSD on another port and have Apache redirect via mod_rewrite, or some other redirect technique.  That seems to be the only way to get any reasonable level of support for OpenACS on these forums since the majority run AolServer.  It amazes me that most in this group cling to a web server despite the fact that Apache runs over 60% of the Web(re:  It also appears that the mothership (ARSDigita) has also changed their choice of web server with their Java rewrite initiative.  Grumble, grumble.

At least the bug fixes in OpenACS 3.2.5 give me a good reason to change my web server config and upgrade from 3.2.4.