Keepalives win32
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From: Bruce Momjian on 30 Jun 2010 11:17 Tom Lane wrote: > Bruce Momjian <bruce(a)momjian.us> writes: > > I still like #1 because it affects the fewest people, and that option > > uses the RFC defaults only for unset values when others are set. > > What's your idea of "affecting the fewest people"? There is no previous > history to be backward-compatible with, because we never supported > keepalive on Windows before. Well, starting in 9.0, keepalives in libpq will default to 'on': Controls whether client-side TCP keepalives are used. The default value is 1, meaning on, but you can change this to 0, meaning off, if keepalives are not wanted. This parameter is ignored for connections made via a Unix-domain socket. My definition is whether we should affect keepalive behavior for the 99% of people who do not change the libpq defaults, meaning the other keepalive settings. #2 would cause these people to use non-registry-controlled keepalive behavior by using RFC defaults, and even if we use Windows defaults, those defaults might be different for different Windows versions. -- Bruce Momjian <bruce(a)momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + None of us is going to be here forever. + -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Tom Lane on 30 Jun 2010 10:57 Magnus Hagander <magnus(a)hagander.net> writes: >> But you previously stated that this code was ignoring the registry >> values. �So doesn't "system defaults" boil down to whatever Windows' >> wired-in defaults are? > The order is Windows wired-in-defaults -> registry values -> what app chooses. > And yes, we *are* ignoring whatever the user has put in the registry, How does that statement square with your follow-on example? > Assume the user had reconfigured his default in the registry to 1 hour. > If the user makes no config change at all, that means it will run with > 1 hour for idle and 1 second for interval. > If we now set tcp_interval to 10 seconds (to change the default), we > will now also change his idle value back to the system default, so he > will get 2 hours for idle and 10 seconds for interval. Thus, we are > ignoring the changes he made globally on his system. With the code as you have it, yes, but if we do it as I'm suggesting, that doesn't happen --- the effective value of the other parameter doesn't change. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Bruce Momjian on 30 Jun 2010 11:39 Tom Lane wrote: > Bruce Momjian <bruce(a)momjian.us> writes: > > Tom Lane wrote: > >> What's your idea of "affecting the fewest people"? There is no previous > >> history to be backward-compatible with, because we never supported > >> keepalive on Windows before. > > > Well, starting in 9.0, keepalives in libpq will default to 'on': > > Yes, which is already a change in behavior. I don't understand why you > are worrying about "backwards compatibility" to parameter values that > weren't in use before. I think self-consistency of the new version is > far more important than that. I am worried about compatibility/consistency with other Windows processes. > > even if we use Windows defaults, those defaults might be different for > > different Windows versions. > > I'm not sure if that's an issue or not, but if it is, that seems to me > to argue for #2 not #1. I assume if someone modified the registry, they want it to be used for all applications that use keepalives on their system. Also, keep in mind that, unlike the backend, which has postgresql.conf, it is burdensome to set a libpq setting for all applications (without using pg_service.conf). -- Bruce Momjian <bruce(a)momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + None of us is going to be here forever. + -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Magnus Hagander on 30 Jun 2010 10:52 On Wed, Jun 30, 2010 at 16:48, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: > Magnus Hagander <magnus(a)hagander.net> writes: >> On Wed, Jun 30, 2010 at 16:27, Tom Lane <tgl(a)sss.pgh.pa.us> wrote: >>> It's hard to argue about this when most of us have no idea what these >>> "system defaults" are, or whether they really are any different from the >>> RFC values in the first place, or whether ordinary users know how to >>> alter them or even find out their values. �Please provide some >>> background if you want intelligent comments. > >> The system defaults are whatever the user has configured at a machine >> level (by editing the registry, by hand or by tool (including >> policies)). I doubt many users have configured them by hand. There may >> well be tools that do it for them. > > But you previously stated that this code was ignoring the registry > values. �So doesn't "system defaults" boil down to whatever Windows' > wired-in defaults are? The order is Windows wired-in-defaults -> registry values -> what app chooses. And yes, we *are* ignoring whatever the user has put in the registry, making our path Windows documented-wired-in-defaults -> what app chooses if we do this. Windows default for idle is 2 hours, for interval 1 second. Assume the user had reconfigured his default in the registry to 1 hour. If the user makes no config change at all, that means it will run with 1 hour for idle and 1 second for interval. If we now set tcp_interval to 10 seconds (to change the default), we will now also change his idle value back to the system default, so he will get 2 hours for idle and 10 seconds for interval. Thus, we are ignoring the changes he made globally on his system. -- Magnus Hagander Me: http://www.hagander.net/ Work: http://www.redpill-linpro.com/ -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
From: Tom Lane on 30 Jun 2010 10:27
Magnus Hagander <magnus(a)hagander.net> writes: > Do you have an opinion on the two choices for handling keepalives_idle > and keepalives_interval? They basically are: > 1) When not configured, use system defaults. When only one of the two > parameters configured, use RFC default for the other one (overwrite > system default). > 2) When not configured, use RFC defaults (overwrite system defaults). > When only one of the two parameters configured, use RFC default for > the other one (overwrite system default) > 3) When not configured, use system defaults. When only one of the two > parameters configured, throw error. It's hard to argue about this when most of us have no idea what these "system defaults" are, or whether they really are any different from the RFC values in the first place, or whether ordinary users know how to alter them or even find out their values. Please provide some background if you want intelligent comments. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers |