Subject: Re: postfix broken by AF_LOCAL semantics change
To: None <tech-kern@netbsd.org>
From: Perry E.Metzger <perry@piermont.com>
List: tech-kern
Date: 11/28/2003 23:50:18
Perry E.Metzger <perry@piermont.com> writes:

> Matt made the following change to uipc_usrreq.c:
>
>   revision 1.68
>   date: 2003/09/03 21:30:12;  author: matt;  state: Exp;  lines: +18 -6
>   Change the behavor of AF_LOCAL connect() to sleep until the server has
>   accepted the connection.  This can prevent a client from overwhelming a
>   server.
>
> Unfortunately, this changed the semantics of our sockets in such a way
> that the postfix qmgr, when attempting to connect to a unix domain
> socket that no one is accepting on, will block. That makes us
> different from every other Unix, apparently, and causes Postfix to
> seize up horribly under load.
>
> Can we revert this alteration?

FYI, the full change was in fact:

Module Name:	src
Committed By:	matt
Date:		Wed Sep  3 21:30:15 UTC 2003

Modified Files:
	src/sys/kern: uipc_usrreq.c
	src/sys/miscfs/fifofs: fifo_vnops.c
	src/sys/sys: un.h

Log Message:
Change the behavor of AF_LOCAL connect() to sleep until the server has
accepted the connection.  This can prevent a client from overwhelming a
server.

Plus there seems to have been some cleanup of various kinds made
afterwards.

-- 
Perry E. Metzger		perry@piermont.com