Apache working but missing httpd-mmn?

Hi all,

In an attempt to set up subversion on a CentOS 4.5 server, I’ve run into an issue where httpd-mmn is required.

root@pixel [~]# yum install mod_dav_svn
Setting up Install Process
Setting up repositories
update                    100% |=========================|  951 B    00:00
base                      100% |=========================| 1.1 kB    00:00
addons                    100% |=========================|  951 B    00:00
extras                    100% |=========================| 1.1 kB    00:00
Reading repository metadata in from local files
Excluding Packages in global exclude list
Parsing package install arguments
Resolving Dependencies
--> Populating transaction set with selected packages. Please wait.
---> Package mod_dav_svn.i386 0:1.1.4-2.ent set to be updated
--> Running transaction check
--> Processing Dependency: httpd-mmn = 20020903 for package: mod_dav_svn
--> Finished Dependency Resolution
Error: Missing Dependency: httpd-mmn = 20020903 is needed by package mod_dav_svn

After an hour of searching, it seems to me that httpd-mmn is included with Apache by default, and is unavoidable to leave out. However, I have recompiled all of Apache (through WHM’s easyapache) and still have the error when trying to install the module.

If anyone has an idea of what can be done, I’d appreciate it!


I’ve never heard of httpd-mmn so I’ve PM’d LinhGB (our Linux expert) and hope that he can be of assistance to you.

Of course, there is always the option of asking the people who put the package together (or the CentOS creators).



Hi dklynn,

Thanks for the reply. I am not sure what httpd-mmn is either, but when looking inside an RPM here (http://rpmfind.net//linux/RPM/fedora/updates/4/i386/httpd-2.0.54-10.4.i386.html) it looks like it’s a static part of Apache. It’s not even listed as a module, rather as part of Apache itself. I might have httpd-mmn but not the required version, as it states 20020903. I am using Apache 2.0, so nothing should be out of date.

So frustrating :slight_smile:

Thanks again for the reply,


Module Magic Number (MMN)

Module Magic Number is a constant defined in the Apache source code that is associated with binary compatibility of modules. It is changed when internal Apache structures, function calls and other significant parts of API change in such a way that binary compatibility cannot be guaranteed any more. On MMN change, all third party modules have to be at least recompiled, sometimes even slightly changed in order to work with the new version of Apache.

Read the definition carefully.

You are installing a packaged module that requires strict version compatibility with a packaged Apache, while your Apache is compiled by yourself. Of course it’s not gonna work. If you’re compiling Apache yourself, welcome to the world of pain: you’ll need to install a lot of development headers and compile the rest of the lot yourself. That’s not even mentioning that everytime there’s a series of upgrades or patches, you’ll get to do all of that over again! Sounds like fun! :rofl:

I really wonder why there are so many people totally new to the Linux/BSD land who dive head-first into compiling something as big and complex as Apache? Even with lots of experience under my belt, I still don’t do that (although I know how to and exactly what it’s for). Just use the distro’s provided Apache, it’ll save you lots of hassles. If a guide you find on the Internet asks you to compile Apache, PHP, MySQL or something big, while assuming that you’re new to Linux/BSD, then that guide is something you shouldn’t follow.