From 8a96651caa669610d4f39f7a289a78f807f5f363 Mon Sep 17 00:00:00 2001 From: Fujii Masao Date: Tue, 16 Feb 2016 15:05:30 +0900 Subject: [PATCH] Correct the formulas for System V IPC parameters SEMMNI and SEMMNS in docs. In runtime.sgml, the old formulas for calculating the reasonable values of SEMMNI and SEMMNS were incorrect. They have forgotten to count the number of semaphores which both the checkpointer process (introduced in 9.2) and the background worker processes (introduced in 9.3) need. This commit fixes those formulas so that they count the number of semaphores which the checkpointer process and the background worker processes need. Report and patch by Kyotaro Horiguchi. Only the patch for 9.3 was modified by me. Back-patch to 9.2 where the checkpointer process was added and the number of needed semaphores was increased. Author: Kyotaro Horiguchi Reviewed-by: Fujii Masao Backpatch: 9.2 Discussion: http://www.postgresql.org/message-id/20160203.125119.66820697.horiguchi.kyotaro@lab.ntt.co.jp --- doc/src/sgml/runtime.sgml | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 7e570a7477f..1045b398ab0 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -640,13 +640,13 @@ psql: could not connect to server: No such file or directory SEMMNI Maximum number of semaphore identifiers (i.e., sets) - at least ceil((max_connections + autovacuum_max_workers + 4) / 16) + at least ceil((max_connections + autovacuum_max_workers + 5) / 16) SEMMNS Maximum number of semaphores system-wide - ceil((max_connections + autovacuum_max_workers + 4) / 16) * 17 plus room for other applications + ceil((max_connections + autovacuum_max_workers + 5) / 16) * 17 plus room for other applications @@ -721,7 +721,7 @@ psql: could not connect to server: No such file or directory linkend="sysvipc-parameters">). The parameter SEMMNI determines the limit on the number of semaphore sets that can exist on the system at one time. Hence this parameter must be at - least ceil((max_connections + autovacuum_max_workers + 4) / 16). + least ceil((max_connections + autovacuum_max_workers + 5) / 16). Lowering the number of allowed connections is a temporary workaround for failures, which are usually confusingly worded No space -- 2.39.5