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runaway-processes [2017/03/01 16:06] – [How can I identify a runaway process on my computer?] brysonltrunaway-processes [2017/03/01 16:08] (current) – [Stay logged in] brysonlt
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 See //man w//, //man top//, //man ps//, and //man grep// for more information about any of these commands. See //man w//, //man top//, //man ps//, and //man grep// for more information about any of these commands.
-===== Which programs usually runaway? ===== 
  
-When it comes to running away, Vi and Vim are the worst offenders. Any time Vi or Vim are closed without using the :q command, they ignore the standard kill signal and run forever. This happens whenever a bash window is closed without Vi being exited first, or whenever an ssh session is interrupted while using Vi. 
 =====Killing runaways===== =====Killing runaways=====
 ====kill==== ====kill====
  
-kill is the standard Unix utility for terminating nasty processes. You only have the right to kill your own processes. Some processes do not respond to the standard kill command. These processes might need a more forceful signal such as -9. The command killall can help you to kill multiple processes at once. man kill and man killall will give you the details about these commands. +kill is the standard Unix utility for terminating nasty processes. You only have the right to kill your own processes. Some processes do not respond to the standard kill command. These processes might need a more forceful signal such as -9. The command killall can help you to kill multiple processes at once. //man kill// and //man killall// will give you the details about these commands.
-====userkill====+
  
-Tyler Larson wrote a utility that will allow runaway processes to be killed without root privileges. Before userkill will terminate a process, it examines the specified process to see if it matches criteria which would signify that it is in fact a runaway. These criteria are: 
- 
-    The process must not be owned by the system (uid<100). 
-    The owner of the process is not logged in. In this case you should message the owner using the write command. If that fails, you should inform the System Administrators of the problem. 
-    The process must not be niced greater than 9. 
-    The CPU must not be more than 10% idle. 
-    All runaway processes combined must be using more than 70% of the CPU. 
-    The process must have already consumed an outrageous amount of CPU time. 
- 
-userkill functions in a manner very similar to kill. The basic syntax is userkill <killsignal> <processid>. The killsignal field defaults to the standard sigterm signal. To send a stronger kill signal (such as -9) you must specify it. The userkill binary (program) is located in /usr/network/bin. 
  
 ====The System Administrators==== ====The System Administrators====
  
-If you can not kill a process using kill or userkill, and you think that it is taking an inappropriate share of system resources, please report it to the System Administrators in room 1140 TMCB or send an email to system@cs.byu.edu.+If you can not kill a process using kill, and you think that it is taking an inappropriate share of system resources, please report it to the System Administrators in room 1140 TMCB or open at ticket at [[https://support.cs.byu.edu|support.cs.byu.edu]].
 ===== How not to have your process killed ===== ===== How not to have your process killed =====
 ==== Use nice and renice ==== ==== Use nice and renice ====
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 You can tell the priority of a process using top. The PRI column (third) is the priority of each process, and the NI column (fourth) is the nice value of each process. By default nice sets the nice value to 10. 19 is the highest possible nice value (lowest priority). For more information, see the man pages. You can tell the priority of a process using top. The PRI column (third) is the priority of each process, and the NI column (fourth) is the nice value of each process. By default nice sets the nice value to 10. 19 is the highest possible nice value (lowest priority). For more information, see the man pages.
-====Stay logged in==== 
- 
-Userkill can not kill your process while you are logged in. You are also better able to monitor your use of system resources if you stay logged in. Be advised, however, that the System Administrators are authorized to kill your process and log you out if they feel that you are inappropriately monopolizing system resources. This usually involves being logged in and idle for an hour, maintaining a high load on the machine when the labs are being heavily used, or otherwise preventing others from using the system for extended periods of time. 
  
 ====Get prior authorization==== ====Get prior authorization====
  
 If you feel that you need to run a process that will be exceptionally resource intensive or that needs to run for an extended period of time, you need to get prior approval to run that process so that it does not get killed. Such approval must be granted through the department CSRs at the request of a sponsoring professor. In such a situation, it is probably just as easy to get permission to use the Fulton Supercomputer The Supercomputer is much more appropriate for most resource intensive research and projects than the open lab machines. If you feel that you need to run a process that will be exceptionally resource intensive or that needs to run for an extended period of time, you need to get prior approval to run that process so that it does not get killed. Such approval must be granted through the department CSRs at the request of a sponsoring professor. In such a situation, it is probably just as easy to get permission to use the Fulton Supercomputer The Supercomputer is much more appropriate for most resource intensive research and projects than the open lab machines.

runaway-processes.1488409574.txt.gz · Last modified: 2017/03/01 16:06 by brysonlt