[Linux-cluster] Add option SO_LINGER to dlm sctp socket when the other endpoint is down.

[Dongmao Zhang]

hi, Dave

于 2013年11月20日 00:51, David Teigland 写道:
> On Tue, Nov 19, 2013 at 03:21:41PM +0100, Lars Marowsky-Bree wrote:
>> The goal here is that we know the other endpoint is down (we received a
>> node down event and have completed fencing at that stage). Hence,
>> SO_LINGER to speed up the shutdown of the socket seems appropriate.
>
> Should your patch do the same with tcp?
> Is this problem especially prevalent with sctp?
This patch is only for sctp, because the normal stop is insanely 
slow(about 10min) when the endpoint is gone(rfc4906).

TCP does not need this. Even if the endpoint is down, tcp could close 
quickly.

>> (We may actually only want to set SO_LINGER for the node down event
>> case, not generally. On receiving node down, set SO_LINGER as described
>> here. Otherwise, we may hit the corner cases in the first reference; but
>> we're already exposed to that today.)
>
> I'd suggest giving this a try.
>
SO_LINGER of sctp really makes sense in this situation. there is no need
to close connection gracefully when we already know the other node is down.


Dongmao Zhang