Обсуждение: "postmaster became multithreaded" is reachable
ExitPostmaster() says:
/*
* There is no known cause for a postmaster to become multithreaded after
* startup. Recheck to account for the possibility of unknown causes.
* This message uses LOG level, because an unclean shutdown at this point
* would usually not look much different from a clean shutdown.
*/
if (pthread_is_threaded_np() != 0)
ereport(LOG,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg_internal("postmaster became multithreaded"),
errdetail("Please report this to <%s>.", PACKAGE_BUGREPORT)));
We now have a report[1] of a way to trigger this error message.
It seems to boil down to "cause an error before PostmasterMain
has reached its test of pthread_is_threaded_np()", for example
$ # build with --enable-nls, using MacPorts' gettext package
$ unset LANG
$ postgres -D /foo
postgres: could not access directory "/foo": No such file or directory
Run initdb or pg_basebackup to initialize a PostgreSQL data directory.
2025-01-23 18:16:03.843 GMT [41524] LOG: postmaster became multithreaded
2025-01-23 18:16:03.843 GMT [41524] DETAIL: Please report this to <pgsql-bugs@lists.postgresql.org>.
I suggest therefore that we remove the "Please report a bug"
bit and instead use the much more helpful hint appearing in
PostmasterMain:
errhint("Set the LC_ALL environment variable to a valid locale.")));
An alternative idea (that maybe should also be done in PostmasterMain)
is to report the HINT only #ifdef __darwin__ and on other platforms
use the "Please report a bug" text.
regards, tom lane
[1] https://www.postgresql.org/message-id/18783-d1873b95a59b9103%40postgresql.org
On Thu, Jan 23, 2025 at 01:22:13PM -0500, Tom Lane wrote:
> ExitPostmaster() says:
>
> /*
> * There is no known cause for a postmaster to become multithreaded after
> * startup. Recheck to account for the possibility of unknown causes.
> * This message uses LOG level, because an unclean shutdown at this point
> * would usually not look much different from a clean shutdown.
> */
> if (pthread_is_threaded_np() != 0)
> ereport(LOG,
> (errcode(ERRCODE_INTERNAL_ERROR),
> errmsg_internal("postmaster became multithreaded"),
> errdetail("Please report this to <%s>.", PACKAGE_BUGREPORT)));
>
> We now have a report[1] of a way to trigger this error message.
> It seems to boil down to "cause an error before PostmasterMain
> has reached its test of pthread_is_threaded_np()", for example
>
> $ # build with --enable-nls, using MacPorts' gettext package
> $ unset LANG
> $ postgres -D /foo
> postgres: could not access directory "/foo": No such file or directory
> Run initdb or pg_basebackup to initialize a PostgreSQL data directory.
> 2025-01-23 18:16:03.843 GMT [41524] LOG: postmaster became multithreaded
> 2025-01-23 18:16:03.843 GMT [41524] DETAIL: Please report this to <pgsql-bugs@lists.postgresql.org>.
That makes sense. Thanks for confirming it.
> I suggest therefore that we remove the "Please report a bug"
> bit and instead use the much more helpful hint appearing in
> PostmasterMain:
>
> errhint("Set the LC_ALL environment variable to a valid locale.")));
That suffices. It took a lot of years for the "Please report" message to
yield a report, so I'm not much concerned about losing reports from this
change.
> An alternative idea (that maybe should also be done in PostmasterMain)
> is to report the HINT only #ifdef __darwin__ and on other platforms
> use the "Please report a bug" text.
I gather pthread_is_threaded_np() is still macOS-only, in which case the
!darwin branch would be future-proofing only.
Another alternative would be to track whether we reached the startup-time
check, emitting a message at exit only if we did reach the startup-time check.
If a postmaster passes the startup-time check and fails the exit-time check,
changing the environment won't help. Even so, I'm content with your first
proposal.
> [1] https://www.postgresql.org/message-id/18783-d1873b95a59b9103%40postgresql.org
Noah Misch <noah@leadboat.com> writes:
> On Thu, Jan 23, 2025 at 01:22:13PM -0500, Tom Lane wrote:
>> An alternative idea (that maybe should also be done in PostmasterMain)
>> is to report the HINT only #ifdef __darwin__ and on other platforms
>> use the "Please report a bug" text.
> I gather pthread_is_threaded_np() is still macOS-only, in which case the
> !darwin branch would be future-proofing only.
Ah, I had not realized that. Perhaps the comments about this code
should mention that?
> Another alternative would be to track whether we reached the startup-time
> check, emitting a message at exit only if we did reach the startup-time check.
> If a postmaster passes the startup-time check and fails the exit-time check,
> changing the environment won't help. Even so, I'm content with your first
> proposal.
Yeah, seems like overcomplication. Let's go with the simple way.
regards, tom lane
On Thu, Jan 23, 2025 at 01:51:32PM -0500, Tom Lane wrote: > Noah Misch <noah@leadboat.com> writes: > > On Thu, Jan 23, 2025 at 01:22:13PM -0500, Tom Lane wrote: > >> An alternative idea (that maybe should also be done in PostmasterMain) > >> is to report the HINT only #ifdef __darwin__ and on other platforms > >> use the "Please report a bug" text. > > > I gather pthread_is_threaded_np() is still macOS-only, in which case the > > !darwin branch would be future-proofing only. > > Ah, I had not realized that. Perhaps the comments about this code > should mention that? Sure, your committed comment works for me. > > Another alternative would be to track whether we reached the startup-time > > check, emitting a message at exit only if we did reach the startup-time check. > > If a postmaster passes the startup-time check and fails the exit-time check, > > changing the environment won't help. Even so, I'm content with your first > > proposal. > > Yeah, seems like overcomplication. Let's go with the simple way. postgr.es/c/4f15759bdcddd23e874526a6b2c0ff86e0beb042 looks fine. Thanks.