process killing

[Prashanth Waugh]

hello friends
In general what is the impact of process killing on unix system whether the load on the system will increase or decrese.

[Piergiacomo Perini]

Hi prashant,

and welcome to the ITRCforums.

General speaking when you kill a process load system could decrease.

my 2 cent
best regards
pg

ps :And as Peter Godron says

Please also read:
http://forums1.itrc.hp.com/service/forums/helptips.do?#33
on how to reward any useful answers given to your questions.

[Pete Randall]

The answer to that one has to be "it depends".

First off, is the process that is being killed actually doing something to consume resources? If so, then, obviously, the system's load will decrease.

If you're asking if the actual killing consumes resources, the answer is minimal.

The thing you want to be careful of is using kill -9, which is an immediate kill. This does not allow the process to clean up after itself and can therefore end up consuming memory and other resources that do not get returned to the system.


Pete

[Dennis Handly]

Along with what Pete says, if you kill a system process like NFS, it could cause a hang.

Was there a reason you are asking this question?

If you have a runaway process, you could at least renice it, if you don't know if it safe to kill.

[Prashanth Waugh]

Thanks dears
I am working as junior administrator (new in the unix world).the problem is that i am using oracle 8i on unix platform. when i am killing the processes regarding oracle .what will be its result on system average load.

[Maxim Yakimenko]

be aware - you can kill down whole instance :)

[Maxim Yakimenko]

2 Pete Randall
As I thought when process gets killed OS frees resources occupied by this process.

[Piergiacomo Perini]

Hi again,
pay attention that if you kill pmon unix process you can cause Oracle shutdown.
If you kill unix process that are similar to this:

oracleSID (DESCRIPTION=(LOCAL=no)(ADDRESS=(PROTOCOL=BEQ)))

and that is call "spid or shadow process id" you can decrease load of your box (BUT you have to kill also relative session IN oracle db).

hth
regards
pg

[spex]

Hello,

> when i am killing the processes regarding
> oracle .what will be its result on system
> average load.

Typically, the system load will decrease, but you need to be careful what you kill. In general, processes whose arguments include "LOCAL=NO" are safe. But the preferred method of terminating an Oracle session (and therefore server processes) is through the Oracle RDBMS itself:

SQL> SELECT s.sid,
p.spid,
s.osuser,
s.program
FROM v$process p,
v$session s
WHERE p.addr = s.paddr;

SQL> ALTER SYSTEM KILL SESSION 'sid,serial#' IMMEDIATE;

PCS