postgres.git / summary / log / commit / refs

commit    a35896c4b2a18b84f35c2cc6a9f5aee6ba041c43
Author:   Thomas Munro <tmunro@postgresql.org>
Date:     Mon Jun 08 01:20:46 2020 +0000
First released in: 14.0, 10.14, 11.9, 12.4, 13.0

    Doc: Update example symptom of systemd misconfiguration.
    
    In PostgreSQL 10, we stopped using System V semaphores on Linux
    systems.  Update the example we give of an error message from a
    misconfigured system to show what people are most likely to see these
    days.
    
    Back-patch to 10, where PREFERRED_SEMAPHORES=UNNAMED_POSIX arrived.
    
    Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
    Discussion: https://postgr.es/m/CA%2BhUKGLmJUSwybaPQv39rB8ABpqJq84im2UjZvyUY4feYhpWMw%40mail.gmail.com


 doc/src/sgml/runtime.sgml | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index f16bc455822..8e0b4fb984b 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1207,7 +1207,7 @@ project.max-msg-ids=(priv,4096,deny)
 
    <para>
     If <productname>systemd</productname> is in use, some care must be taken
-    that IPC resources (shared memory and semaphores) are not prematurely
+    that IPC resources (including shared memory) are not prematurely
     removed by the operating system.  This is especially of concern when
     installing PostgreSQL from source.  Users of distribution packages of
     PostgreSQL are less likely to be affected, as
@@ -1224,11 +1224,12 @@ project.max-msg-ids=(priv,4096,deny)
    </para>
 
    <para>
-    A typical observed effect when this setting is on is that the semaphore
-    objects used by a PostgreSQL server are removed at apparently random
-    times, leading to the server crashing with log messages like
+    A typical observed effect when this setting is on is that shared memory
+    objects used for parallel query execution are removed at apparently random
+    times, leading to errors and warnings while attempting to open and remove
+    them, like
 <screen>
-LOG: semctl(1234567890, 0, IPC_RMID, ...) failed: Invalid argument
+WARNING:  could not remove shared memory segment "/PostgreSQL.1450751626": No such file or directory
 </screen>
     Different types of IPC objects (shared memory vs. semaphores, System V
     vs. POSIX) are treated slightly differently


[parent: f7faf4a5d779]