From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [PATCH 4/4] Add some content to the readme.txt for socket c/r Date: Fri, 23 Oct 2009 15:41:23 -0400 Message-ID: <4AE206E3.7010904@librato.com> References: <1256072803-3518-1-git-send-email-danms@us.ibm.com> <1256072803-3518-5-git-send-email-danms@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1256072803-3518-5-git-send-email-danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Dan Smith Cc: containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org List-Id: containers.vger.kernel.org Dan Smith wrote: > Signed-off-by: Dan Smith Nicely put ! > --- > Documentation/checkpoint/readme.txt | 21 +++++++++++++++++++++ > 1 files changed, 21 insertions(+), 0 deletions(-) > > diff --git a/Documentation/checkpoint/readme.txt b/Documentation/checkpoint/readme.txt > index 571c469..e6c173d 100644 > --- a/Documentation/checkpoint/readme.txt > +++ b/Documentation/checkpoint/readme.txt > @@ -334,6 +334,27 @@ we will be forced to more carefully review each of those features. > However, this can be controlled with a sysctl-variable. > > > +Sockets > +======= > + > +For AF_UNIX sockets, both endpoints must be within the checkpointed > +task set to maintain a connected state after restart. UNIX sockets > +that are in the process of passing a descriptor will cause the > +checkpoint to fail with -EBUSY indicating a transient state that > +cannot be checkpointed. Listening sockets with an unaccepted peer > +will also cause an -EBUSY result. > + > +AF_INET sockets with endpoints outside the checkpointed task set may > +remain open if care is taken to avoid TCP timeouts and resets. > +Careful use of a virtual IP address can help avoid emission of an RST > +to the non-checkpointed endpoint. If desired, the > +RESTART_SOCK_LISTENONLY flag may be passed to the restart syscall > +which will cause all connected AF_INET sockets to be closed during the > +restore process. Listening sockets will still be restored to their > +original state, which makes this mode a candidate for something like > +an HTTP server. > + > + > Kernel interfaces > ================= >