1 NSSM: The Non-Sucking Service Manager
\r
2 Version 2.17, 2013-11-12
\r
4 NSSM is a service helper program similar to srvany and cygrunsrv. It can
\r
5 start any application as an NT service and will restart the service if it
\r
6 fails for any reason.
\r
8 NSSM also has a graphical service installer and remover.
\r
10 Full documentation can be found online at
\r
14 Since version 2.0, the GUI can be bypassed by entering all appropriate
\r
15 options on the command line.
\r
17 Since version 2.1, NSSM can be compiled for x64 platforms.
\r
18 Thanks Benjamin Mayrargue.
\r
20 Since version 2.2, NSSM can be configured to take different actions
\r
21 based on the exit code of the managed application.
\r
23 Since version 2.3, NSSM logs to the Windows event log more elegantly.
\r
25 Since version 2.5, NSSM respects environment variables in its parameters.
\r
27 Since version 2.8, NSSM tries harder to shut down the managed application
\r
28 gracefully and throttles restart attempts if the application doesn't run
\r
29 for a minimum amount of time.
\r
31 Since version 2.11, NSSM respects srvany's AppEnvironment parameter.
\r
33 Since version 2.13, NSSM is translated into French.
\r
34 Thanks François-Régis Tardy.
\r
36 Since version 2.15, NSSM is translated into Italian.
\r
37 Thanks Riccardo Gusmeroli.
\r
39 Since version 2.17, NSSM can try to shut down console applications by
\r
40 simulating a Control-C keypress. If they have installed a handler routine
\r
41 they can clean up and shut down gracefully on receipt of the event.
\r
43 Since version 2.17, NSSM can redirect the managed application's I/O streams
\r
44 to an arbitrary path.
\r
49 In the usage notes below, arguments to the program may be written in angle
\r
50 brackets and/or square brackets. <string> means you must insert the
\r
51 appropriate string and [<string>] means the string is optional. See the
\r
55 Installation using the GUI
\r
56 --------------------------
\r
57 To install a service, run
\r
59 nssm install <servicename>
\r
61 You will be prompted to enter the full path to the application you wish
\r
62 to run and any command line options to pass to that application.
\r
64 Use the system service manager (services.msc) to control advanced service
\r
65 properties such as startup method and desktop interaction. NSSM may
\r
66 support these options at a later time...
\r
69 Installation using the command line
\r
70 -----------------------------------
\r
71 To install a service, run
\r
73 nssm install <servicename> <application> [<options>]
\r
75 NSSM will then attempt to install a service which runs the named application
\r
76 with the given options (if you specified any).
\r
78 Don't forget to enclose paths in "quotes" if they contain spaces!
\r
80 If you want to include quotes in the options you will need to """quote""" the
\r
84 Managing the service
\r
85 --------------------
\r
86 NSSM will launch the application listed in the registry when you send it a
\r
87 start signal and will terminate it when you send a stop signal. So far, so
\r
88 much like srvany. But NSSM is the Non-Sucking service manager and can take
\r
89 action if/when the application dies.
\r
91 With no configuration from you, NSSM will try to restart itself if it notices
\r
92 that the application died but you didn't send it a stop signal. NSSM will
\r
93 keep trying, pausing between each attempt, until the service is successfully
\r
94 started or you send it a stop signal.
\r
96 NSSM will pause an increasingly longer time between subsequent restart attempts
\r
97 if the service fails to start in a timely manner, up to a maximum of four
\r
98 minutes. This is so it does not consume an excessive amount of CPU time trying
\r
99 to start a failed application over and over again. If you identify the cause
\r
100 of the failure and don't want to wait you can use the Windows service console
\r
101 (where the service will be shown in Paused state) to send a continue signal to
\r
102 NSSM and it will retry within a few seconds.
\r
104 By default, NSSM defines "a timely manner" to be within 1500 milliseconds.
\r
105 You can change the threshold for the service by setting the number of
\r
106 milliseconds as a REG_DWORD value in the registry at
\r
107 HKLM\SYSTEM\CurrentControlSet\Services\<service>\Parameters\AppThrottle.
\r
109 NSSM will look in the registry under
\r
110 HKLM\SYSTEM\CurrentControlSet\Services\<service>\Parameters\AppExit for
\r
111 string (REG_EXPAND_SZ) values corresponding to the exit code of the application.
\r
112 If the application exited with code 1, for instance, NSSM will look for a
\r
113 string value under AppExit called "1" or, if it does not find it, will
\r
114 fall back to the AppExit (Default) value. You can find out the exit code
\r
115 for the application by consulting the system event log. NSSM will log the
\r
116 exit code when the application exits.
\r
118 Based on the data found in the registry, NSSM will take one of three actions:
\r
120 If the value data is "Restart" NSSM will try to restart the application as
\r
121 described above. This is its default behaviour.
\r
123 If the value data is "Ignore" NSSM will not try to restart the application
\r
124 but will continue running itself. This emulates the (usually undesirable)
\r
125 behaviour of srvany. The Windows Services console would show the service
\r
126 as still running even though the application has exited.
\r
128 If the value data is "Exit" NSSM will exit gracefully. The Windows Services
\r
129 console would show the service as stopped. If you wish to provide
\r
130 finer-grained control over service recovery you should use this code and
\r
131 edit the failure action manually. Please note that Windows versions prior
\r
132 to Vista will not consider such an exit to be a failure. On older versions
\r
133 of Windows you should use "Suicide" instead.
\r
135 If the value data is "Suicide" NSSM will simulate a crash and exit without
\r
136 informing the service manager. This option should only be used for
\r
137 pre-Vista systems where you wish to apply a service recovery action. Note
\r
138 that if the monitored application exits with code 0, NSSM will only honour a
\r
139 request to suicide if you explicitly configure a registry key for exit code 0.
\r
140 If only the default action is set to Suicide NSSM will instead exit gracefully.
\r
143 Stopping the service
\r
144 --------------------
\r
145 When stopping a service NSSM will attempt several different methods of killing
\r
146 the monitored application, each of which can be disabled if necessary.
\r
148 First NSSM will attempt to generate a Control-C event and send it to the
\r
149 application's console. Batch scripts or console applications may intercept
\r
150 the event and shut themselves down gracefully. GUI applications do not have
\r
151 consoles and will not respond to this method.
\r
153 Secondly NSSM will enumerate all windows created by the application and send
\r
154 them a WM_CLOSE message, requesting a graceful exit.
\r
156 Thirdly NSSM will enumerate all threads created by the application and send
\r
157 them a WM_QUIT message, requesting a graceful exit. Not all applications'
\r
158 threads have message queues; those which do not will not respond to this
\r
161 Finally NSSM will call TerminateProcess() to request that the operating
\r
162 system forcibly terminate the application. TerminateProcess() cannot be
\r
163 trapped or ignored, so in most circumstances the application will be killed.
\r
164 However, there is no guarantee that it will have a chance to perform any
\r
165 tidyup operations before it exits.
\r
167 Any or all of the methods above may be disabled. NSSM will look for the
\r
168 HKLM\SYSTEM\CurrentControlSet\Services\<service>\Parameters\AppStopMethodSkip
\r
169 registry value which should be of type REG_DWORD set to a bit field describing
\r
170 which methods should not be applied.
\r
172 If AppStopMethodSkip includes 1, Control-C events will not be generated.
\r
173 If AppStopMethodSkip includes 2, WM_CLOSE messages will not be posted.
\r
174 If AppStopMethodSkip includes 4, WM_QUIT messages will not be posted.
\r
175 If AppStopMethodSkip includes 8, TerminateProcess() will not be called.
\r
177 If, for example, you knew that an application did not respond to Control-C
\r
178 events and did not have a thread message queue, you could set AppStopMethodSkip
\r
179 to 5 and NSSM would not attempt to use those methods to stop the application.
\r
181 Take great care when including 8 in the value of AppStopMethodSkip. If NSSM
\r
182 does not call TerminateProcess() it is possible that the application will not
\r
183 exit when the service stops.
\r
188 NSSM can redirect the managed application's I/O to any path capable of being
\r
189 opened by CreateFile(). This enables, for example, capturing the log output
\r
190 of an application which would otherwise only write to the console or accepting
\r
191 input from a serial port.
\r
193 NSSM will look in the registry under
\r
194 HKLM\SYSTEM\CurrentControlSet\Services\<service>\Parameters for the keys
\r
195 corresponding to arguments to CreateFile(). All are optional. If no path is
\r
196 given for a particular stream it will not be redirected. If a path is given
\r
197 but any of the other values are omitted they will be receive sensible defaults.
\r
199 AppStdin: Path to receive input.
\r
200 AppStdout: Path to receive output.
\r
201 AppStderr: Path to receive error output.
\r
203 Parameters for CreateFile() are providing with the "AppStdinShareMode",
\r
204 "AppStdinCreationDisposition" and "AppStdinFlagsAndAttributes" values (and
\r
205 analogously for stdout and stderr).
\r
207 In general, if you want the service to log its output, set AppStdout and
\r
208 AppStderr to the same path, eg C:\Users\Public\service.log, and it should
\r
209 work. Remember, however, that the path must be accessible to the user
\r
210 running the service.
\r
213 Removing services using the GUI
\r
214 -------------------------------
\r
215 NSSM can also remove services. Run
\r
217 nssm remove <servicename>
\r
219 to remove a service. You will prompted for confirmation before the service
\r
220 is removed. Try not to remove essential system services...
\r
223 Removing service using the command line
\r
224 ---------------------------------------
\r
225 To remove a service without confirmation from the GUI, run
\r
227 nssm remove <servicename> confirm
\r
229 Try not to remove essential system services...
\r
234 NSSM logs to the Windows event log. It registers itself as an event log source
\r
235 and uses unique event IDs for each type of message it logs. New versions may
\r
236 add event types but existing event IDs will never be changed.
\r
238 Because of the way NSSM registers itself you should be aware that you may not
\r
239 be able to replace the NSSM binary if you have the event viewer open and that
\r
240 running multiple instances of NSSM from different locations may be confusing if
\r
241 they are not all the same version.
\r
246 To install an Unreal Tournament server:
\r
248 nssm install UT2004 c:\games\ut2004\system\ucc.exe server
\r
250 To remove the server:
\r
252 nssm remove UT2004 confirm
\r
255 Building NSSM from source
\r
256 -------------------------
\r
257 NSSM is known to compile with Visual Studio 6, Visual Studio 2005 and Visual
\r
260 NSSM will also compile with Visual Studio 2010 but the resulting executable
\r
261 will not run on versions of Windows older than XP SP2.
\r
266 Thanks to Bernard Loh for finding a bug with service recovery.
\r
267 Thanks to Benjamin Mayrargue (www.softlion.com) for adding 64-bit support.
\r
268 Thanks to Joel Reingold for spotting a command line truncation bug.
\r
269 Thanks to Arve Knudsen for spotting that child processes of the monitored
\r
270 application could be left running on service shutdown, and that a missing
\r
271 registry value for AppDirectory confused NSSM.
\r
272 Thanks to Peter Wagemans and Laszlo Keresztfalvi for suggesting throttling restarts.
\r
273 Thanks to Eugene Lifshitz for finding an edge case in CreateProcess() and for
\r
274 advising how to build messages.mc correctly in paths containing spaces.
\r
275 Thanks to Rob Sharp for pointing out that NSSM did not respect the
\r
276 AppEnvironment registry value used by srvany.
\r
277 Thanks to Szymon Nowak for help with Windows 2000 compatibility.
\r
278 Thanks to François-Régis Tardy for French translation.
\r
279 Thanks to Emilio Frini for spotting that French was inadvertently set as
\r
280 the default language when the user's display language was not translated.
\r
281 Thanks to Riccardo Gusmeroli for Italian translation.
\r
282 Thanks to Eric Cheldelin for the inspiration to generate a Control-C event
\r
284 Thanks to Brian Baxter for suggesting how to escape quotes from the command prompt.
\r
288 NSSM is public domain. You may unconditionally use it and/or its source code
\r
289 for any purpose you wish.
\r