Re: Keepalives win32

Hello, Bruce.

You wrote:

BM> Tom Lane wrote:
>> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> > On Mon, Jun 28, 2010 at 8:24 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> >> What I was trying to say is I think we could dispense with the
>> >> setsockopt() code path, and just always use the WSAIoctl() path anytime
>> >> keepalives are turned on.  I don't know what "system default values"
>> >> you're speaking of, if they're not the registry entries; and I
>> >> definitely don't see the point of consulting such values if they aren't
>> >> user-settable.  We might as well just consult the RFCs and be done.
>>
>> > FWIW, I think I prefer Magnus's approach, but I'm not 100% sure I can
>> > defend that preference...
>>
>> Well, basically what I don't like about Magnus' proposal is that setting
>> one of the two values changes the default that will be used for the
>> other one. (Or, if it does not change the default, the extra code is
>> useless anyway.) If we just always go through the WSAIoctl() path then
>> we can clearly document "the default for this on Windows is so-and-so".
>> How is the documentation going to explain the behavior of the proposed
>> code?

BM> Let's look at the usage probabilities. 99% of Win32 users will not use
BM> any of these settings.

Let me disagree with this statement. As DAC developer I'm faced with
opposite reality. There are a lot of users demanding this
functionality.

BM> I would hate to come up with a solution that
BM> changes the default behavior for that 99%.

BM> Therefore, I think using hard-coded defaults only for cases where
BM> someone sets one but not all settings is appropriate. The documentation
BM> text would be:

BM> On Windows, if a keepalive settings is set, then defaults will be
BM> used for any unset values, specifically, keepalives_idle (200) and
BM> keepalives_interval(4). Windows does not allow control of
BM> keepalives_count.

BM> Seems simple enough.

BM> --
BM> Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
BM> EnterpriseDB http://enterprisedb.com

BM> + None of us is going to be here forever. +

--
With best wishes,
Pavel mailto:pavel(at)gf(dot)microolap(dot)com