I got the following error message after compiling apache against the latest OpenSSL version.
Cannot load modules/mod_fcgid.so into server: undefined symbol: ap_unixd_setup_child
It looks like a compiler error that happened, but it isn’t. In fact, there are two options why there is this error message appears.
One mod_unixd isn’t loaded or loaded after mod_fcgid. Two mod_fcgid can’t create a directory for the socket or the socket itself. aka file permissions.
That error message could be much better. It is misleading. This error does not happen on Windows. It comes from the old Unix philosophy: “Everything is a file”. This lead to a ton of code in the kernels. Even more, code exists for block devices in /dev. All that symlinks and magic directories. I wonder when “Everything is a file” will have exceptions everyone agrees on.
After the install and the required reboot I was able to start bash. At first I was confused where to find the files from the home directory. It isn’t the one from windows itself.
Well I found it in AppData\Local\lxss . So each user has his / her own files.
Since I was able to find most stuff I wanted to know if I am able to compile httpd apache on it. I cloned https://github.com/jblond/debian_build_apache24.git and the build went smooth.
But apache didn’t start. Adding AcceptFilter http none and AcceptFilter https none helped. To get rid of the first error messages. But still apache wasn’t starting. Got the following error message.
[Tue Jan 24 22:31:33.590385 2017] [fcgid:emerg] [pid 1289:tid 140034843477824] (38)Function not implemented: mod_fcgid: Can't create shared memory for size 1200712 bytes
Okay, I disabled mod_fcgid and apache starts with /opt/apache2/bin/httpd -k start . Even running bash.exe ~ as Adminstrator did not solve to run fcgid.
I have to find out how to run mod_fcgid. I like to run PHP over fcgid.
Well I really like mod_fcgid with PHP on my Apaches on Windows. But since every time a PHP process get it’s signal to die, mod_fcgid creates on windows an entry in the error log cause the graceful stop always fails.
There in a patch for that! I made a bug report (54597), but it didn’t go in the code yet. If you wanna patch it yourself, here it is.
--- modules/fcgid/fcgid_pm_main.c (revision 1448988)
+++ modules/fcgid/fcgid_pm_main.c (working copy)
@@ -333,10 +333,17 @@
ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_server,
"mod_fcgid: process %" APR_PID_T_FMT
" graceful kill fail, sending SIGKILL",
+ ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, main_server,
+ "mod_fcgid: process %" APR_PID_T_FMT
+ " graceful kill fail, sending SIGKILL",
With apache 2.3.15 I had kinda the same issue with mod_fcgidon ubuntu 8.04 as on windows. With -k restart or -k graceful the server did not die like on windows, but the server delivered than only a 200 OK response header, but nothing more. Switching from worker mpm to event mpm seemed to solve this, but the server died later :-/
Since it has talmost the same issues like on windows I could make a patch that fixes this. Grab the patch (patched against trunk) for the patch for 2.3.6
The bug 50309 is now longer than a year listet. Bad that none applied it yet.
./configure –prefix=/opt/apache2 –enable-pie –enable-mods-shared=all –enable-authn-dbd –enable-so –disable-include –enable-deflate –enable-headers –enable-expires –enable-ssl=shared –enable-mpms-shared=all –with-mpm=worker –enable-rewrite –with-z=/home/mario/apache24/httpd-2.3.11-beta/srclib/zlib –enable-module=ssl –enable-fcgid
On Windows fcgid crashes apache when apache do a graceful restart (httpd -k restart). Here is a patch that should fix that. This patch in inspired from Tom Dovovan.
--- modules/fcgid/fcgid_pm_main.c (revision 1037552)
+++ modules/fcgid/fcgid_pm_main.c (working copy)
@@ -375,7 +375,9 @@
proc->diewhy = FCGID_DIE_SHUTDOWN;
proc_print_exit_info(proc, exitcode, exitwhy,
+ #ifndef Win32
proc->proc_pool = NULL;
--- modules/fcgid/fcgid_pm_win.c (revision 1037552)
+++ modules/fcgid/fcgid_pm_win.c (working copy)
@@ -123,7 +123,9 @@
"mod_fcgid: can't create wake up thread");
+ apr_pool_cleanup_register(pconf, main_server,
+ procmgr_stop_procmgr, apr_pool_cleanup_null);
@@ -249,8 +251,6 @@
procmgr_child_init(server_rec * main_server, apr_pool_t * pchild)
- apr_pool_cleanup_register(pchild, main_server,
- procmgr_stop_procmgr, apr_pool_cleanup_null);
Download this patch
I made some testing on my dev machine and liked event mpm. So I installed it here. I noticed that the event mpm closes the connections faster than worker mpm. Some download tests sadisfied me. Less memory usage and faster serving :-) For now I keeped the settings from worker mpm. I’ll look for tweaking in the next days.
Different to the docs event mpm works fine with SSL.
sudo apt-get install apache2-mpm-event libapache2-mod-fcgid
Also the serving PHP over fcgid is nice. The implementation of PHP over fcgid in the older post.
Today I changed my server to from prefork mpm to worker mpm.
There are only some issues: in my phpmyadmin I had to set auth from http to cookie. And PHP_ADMIN_VALUE don’t work in the vhosts.
How to install it:
sudo apt-get install apache2-mpm-worker libapache2-mod-fcgid
In the single vhosts
Options Indexes ExecCGI
AddHandler fcgid-script .php
FCGIWrapper /usr/lib/cgi-bin/php5 .php
So that isn’t hard to do.
Well I would like to have a windows server with apache which is also threaded like worker mpm, but there is no cheap hoster for that yet. At home have that server is not an option cause of the small upload I have with my DSL, the coast of energie and where the hell should I put that server in my small apartment to that I still can sleep?