mod_mono man page

mod_mono — apache module that enables ASP.NET pages. Works together with mod-mono-server.exe


mod_mono is a simple module that works with Apache 2.0 or newer.

It needs mod-mono-server.exe installed on the system. By default, it will attemp to run mod-mono-server.exe if it doesn't find it's running.

Configuration Directives

All the directives but MonoSetServerAlias accept an optional first argument that is the mod-mono-server instance alias for which the directive applies.  If only one argument is provided for them, thr directive will apply to the 'default' mod-mono-server instance. Refer to the monodoc documentation on configuring mod_mono for more examples.


It accepts an octal number as a parameter. The number must be a valid unix file creation mask value (see umask(2)). The mask will be applied whenever a directory or file is created from within an ASP.NET application. Default value: "0077".


It accepts a file name as argument. That file will be a named pipe used to send/receive data from/to mod_mono to/from mod-mono-server. You cannot use MonoListenPort and MonoUnixSocket at the same time. Default value: "/tmp/mod_mono_server".


TCP port on which mod-mono-server should listen/is listening on. Mutually exclusive with MonoUnixSocket. When this options is specified, mod-mono-server and mod_mono will use a TCP socket for communication. Default value: none

MonoListenBacklog N

The backlog of connections to set on the listener socket in mod-mono-server. By default the value is set to 500.

MonoMinThreads N

The minimum number of threads the threadpool allocates in mod-mono-server. Increase this value to better handle the sudden arrival of connections. The default value is determined by the mono runtime.


IP address where mod-mono-server should listen/is listening on. Can only be used when MonoListenPort is specified. Default value: ""


If the value is True, it tells mod_mono to spawn mod-mono-server.exe if it's not already running. If set to False, most of these directives are useless. Default value: True


Number of times mod_mono will attempt to start a backend which died. Value cannot be lower than 0. Default value: 3


Number of seconds to wait after starting the backend. This is to let the backend initialize properly before attempting to connect to it. Value cannot be lower than 2. Default value: 2


Set the auto-restart mode for the backend(s). Three modes are available: None - do not auto-restart, Requests - restart after a configured number of  requests served, Time - restart after the backend has been up for the specified period of time.  Note that if you enable auto-restart you should consider using off-process state server, since on every restart your application state will be lost. Default value: None


Number of requests for a backend to serve before auto-restarting. The value here  is taken into account only when MonoAutoRestartMode is set to Requests. Default value: 10000


Time after which the backend should be auto-restarted. The time format is: DD[:HH[:MM[:SS]]]. Default value: 00:12:00:00

MonoExecutablePath (Obsoleted, ignored)

Don't use this. It is ignored and has been left here for compatibility purposes. Default value: "/usr/bin/mono"


This value will be used to set the MONO_PATH environment variable. Default value: ""


The full path to the mod-mono-server script. Default value: "/usr/bin/mod-mono-server"


If MonoRunXSP is True, this option selects the .NET framework version to use. This affects the backend that is started to service the requests. The MonoServerPath option takes precedence over this setting. Available values are "2.0", "3.5" and "4.0".  Default value: "2.0"


The directory where mono runtime will create the ".wapi" directory used to emulate windows I/O. It's used to set MONO_SHARED_DIR. Default value: "/tmp"


The directory passed in --root argument when launching mod-mono-server.


If MonoRunXSP is True, CPU time limit in seconds allowed for the spawned mono process. Beyond that, it will be restarted. If this capability is not available on your system, the directive will be ignored. Default value: system default


If MonoRunXSP is True, the maximum size of the process's data segment (data size) in bytes allowed for the spawned mono process. It will be restarted when the limit is reached. If this capability is not available on your system, the directive will be ignored. Default value: system default


This value will be passed to mod-mono-server.exe in the --applications option. See xsp(1) manual page for details.


The argument passed in --appconfigfile argument to mod-mono-server. Default value: NULL.


The argument passed in --appconfigdir argument to mod-mono-server. Default value: config/mod-mono-applications

Note that you must specify at least one of MonoApplications, MonoApplicationsConfigFile and MonoApplicationsConfigDir.


Enables or disables automatic ASP.NET applications discovery. By default it is enabled if you have no application configured. Otherwise, it's disabled. The possible values are 'enabled' or 'disabled'.


Runs mono in debug mode, which produces stack traces with line numbers. Default value: False.


Takes a server alias name. This is to be used inside <Directory> or <Location>. Default value: 'default' if the directive is not used.


Takes a string of 'name=value' pairs separated by semicolons. For each pair, it calls setenv (name, value) before running mod-mono-server.


Takes alias name and a string of the same format and meaning as the MONO_IOMAP environment variable (see the mono(1) manpage). The effect is that mod_mono performs the same actions as mono runtime with MONO_IOMAP in effect, as well as that the MONO_IOMAP variable with the specified value is exported in the backend environment. This option is necessary when you're using MONO_IOMAP in your application and there might be static files with mixed case names - in such case mod_mono attempts to open the file directly and sends it using apache facilities. Default value: none


The maximum number of concurrent requests mod_mono will pass off to the ASP.NET backend. Set to zero to turn off the limit. Default value: 0.


The maximum number of concurrent requests mod_mono will hold while the ASP.NET backend is busy with the maximum number of requests specified by MonoMaxActiveRequests. Requests that can't be processed or held are dropped with Service Unavailable. Default value: 150.


Do not protect hidden files/directories from being accessed by clients. Hidden files/directories are those with  Hidden attribute on Windows and whose name starts with a dot on Unix. Any file/directory below a hidden directory is inacessible. This option turns the default behavior of protecting such locations off. If your application does not contain any hidden files/directories, you might want to use this option as the checking process has a per-request cost. Accepts a boolean value - 'true' or 'false' Default value: true.  AppSettings key name: MonoServerCheckHiddenFiles.

Sample Virtual Host Configuration

Note that the configuration below requires the mod_mono module to be  loaded by Apache. How it is done is distribution-specific - please check your distribution documentation for details.

This one using <Directory>:

      Alias /mono "/usr/lib/xsp/test"
      AddMonoApplications default "/mono:/usr/lib/xsp/test"
      <Directory /usr/lib/xsp/test>
              SetHandler mono
              <IfModule mod_dir.c>
                    DirectoryIndex index.aspx

This one using <Location>:

      Alias /demo "/usr/lib/xsp/test"
      AddMonoApplications default "/demo:/usr/lib/xsp/test"
      <Location /demo>
              SetHandler mono

If you prefer to .webapp configuration file(s) (see manual page of xsp), you can change MonoApplications in the above samples by:

      MonoApplicationsConfigFile default "/var/www/applications.webapp"

replacing the path to the file with yours.

If you want to use several .webapp files, use this instead:

      MonoApplicationsConfigDir default "/var/www/webapp"

and all the .webapp files found in the directory /var/www/webapp will be loaded.

Refer to monodoc documentation on configuring mod_mono for more examples.

The Mod_mono Control Panel

mod_mono provides a simple web-based control panel for restarting the  mod-mono-server, which is useful when assemblies need to be reloaded  from disk after they have been changed.  To activate the control panel, place the following in your httpd.conf:

            <Location /mono>
              SetHandler mono-ctrl
              Order deny,allow
              Deny from all
              Allow from

The control panel is then accessible at  Clicking the link to restart mod-mono-server will immediately restart  it.

The Order/Deny/Allow access controls above restrict access to the  control panel to the computer with IP address Replace this  (or add more Allow lines) with the IP address of your own computer so  that you can access the control panel.  You can also use Apache's  htaccess features to password protect it, too.

Environment Variables

It may modify MONO_PATH, PATH and MONO_SHARED_DIR when starting mod-mono-server.

The MOD_MONO_CCV variable may be used to select which component will do client certificate validity (CCV) checks. By default both Apache and Mono will verify the client certificates. This can be changed to either "apache" or "mono" to limit the validity check to either environment. This variable can be set using MonoSetEnv to allow different vhost to  use separate validation techniques.

The MOD_MONO_LOCKING_MECHANISM variable may be used to choose the APR locking mechanism for the dashboard. The currently defined mechanism names are: DEFAULT, FCNT, FLOCK, SYSVSEM, PROC_PTHREAD, POSIXSEM. Note that not every mechanism may be available for your platform. In such case, mod_mono will fallback to using the DEFAULT value which lets the APR decide which locking mechanism to use. DEFAULT is also the default value for the option if the environment variable is not set or its value is unknown. This value MUST NOT be set using MonoSetEnv - it MUST be present in the Apache environment before the module is initialized and its configuration parsed.




mod_mono was started by Daniel Ridruejo (daniel rawbyte com). Currently, Marek Habersack ( is the maintainer.

Mailing Lists

See for details.

Web Site

Visit for details.

See Also


Referenced By

asp-state(1), dbsessmgr(1), mono(1), xsp(1).

28 Jan 2009 mod_mono 3.12 ASP.NET Support for Apache