9fans - fans of the OS Plan 9 from Bell Labs
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From: arisawa <arisawa@ar.aichi-u.ac.jp>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] protection against resource exhaustion
Date: Wed, 28 Jan 2015 15:50:16 +0900	[thread overview]
Message-ID: <A97D4AC3-3160-448A-BAAE-562FD1529B6C@ar.aichi-u.ac.jp> (raw)
In-Reply-To: <1fccf1df5e46d5fa5235a40a90a001e3@brasstown.quanstro.net>

Hello,

> nonetheless, i have experience running multi-user plan 9 systems, and users
> were not usually the issue.

Eric’s users are all gentleman, all careful people and all skillful programmers.
If your system is served for university students, you will have different thought.

> i think you've turned a problem with bounded recovery time into a
> situation where the recovery code itself will inadvertently dos attack its
> users.

in case that a process failed in getting resource such as memory or process, 
what it should do is very limited: puts out some message and exits.
this is right behavior.
I have never seen programs that retry malloc() or fork() until succeed.
if all processes retry them, the system will get down.
this is what I have observed in current plan9 kernel.

if any one has cleaner solution, i.e., a solution that never kill innocent process,
I want to see it.





  reply	other threads:[~2015-01-28  6:50 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-25  6:16 arisawa
2015-01-25  6:59 ` mischief
2015-01-25 17:41   ` erik quanstrom
2015-01-26 11:47     ` arisawa
2015-01-26 12:46       ` cinap_lenrek
2015-01-26 14:13       ` erik quanstrom
2015-01-27  0:33         ` arisawa
2015-01-27  1:30           ` Lyndon Nerenberg
2015-01-27  4:13             ` erik quanstrom
2015-01-27  4:22           ` erik quanstrom
2015-01-27  7:03             ` arisawa
2015-01-27  7:10               ` Ori Bernstein
2015-01-27  7:15                 ` lucio
2015-01-27 14:05                 ` erik quanstrom
2015-01-27  7:12               ` lucio
2015-01-27 14:10               ` erik quanstrom
2015-01-28  0:10                 ` arisawa
2015-01-28  3:38                   ` erik quanstrom
2015-01-28  6:50                     ` arisawa [this message]
2015-01-28  7:22                       ` lucio
2015-01-28  7:48                       ` Quintile
2015-01-28 13:13                       ` cinap_lenrek
2015-01-28 14:03                         ` erik quanstrom
2015-01-28 14:09                           ` lucio
2015-01-28 14:14                             ` erik quanstrom
2015-01-28 14:53                               ` lucio
2015-01-28 17:02                                 ` Skip Tavakkolian
2015-01-28 14:16                       ` erik quanstrom
2015-01-28 17:28                       ` Charles Forsyth
2015-01-28 17:39                         ` cinap_lenrek
2015-01-28 18:51                           ` Charles Forsyth
2015-01-29  3:57                             ` arisawa
2015-01-29  6:34                               ` erik quanstrom
2015-01-29  6:42                         ` erik quanstrom
2015-01-29  8:11                           ` arisawa
2015-01-27 10:53             ` Charles Forsyth
2015-01-27 14:01               ` erik quanstrom
2015-01-25  9:04 ` arisawa
2015-01-25 11:06   ` Bence Fábián

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