Re: Keepalives win32 - Mailing list pgsql-hackers

From Pavel Golub
Subject Re: Keepalives win32
Date
Msg-id 632069029.20100630093214@gf.microolap.com
Whole thread Raw
In response to Re: Keepalives win32  (Bruce Momjian <bruce@momjian.us>)
Responses Re: Keepalives win32
List pgsql-hackers
Hello, Bruce.

You wrote:

BM> Tom Lane wrote:
>> Robert Haas <robertmhaas@gmail.com> writes:
>> > On Mon, Jun 28, 2010 at 8:24 PM, Tom Lane <tgl@sss.pgh.pa.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@momjian.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@gf.microolap.com



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