On Fri, Jul 10, 2020 at 05:13:26PM +0200, Julien Rouhaud wrote: > There's a thinko in the padding handling. It should be dones whether MyProc > and/or lockGroupLeader is NULL or not, and only if padding was asked, like > it's > done for case 'd' for instance. > > Also, the '%k' escape sounds a bit random. Is there any reason why we don't > use any uppercase character for log_line_prefix? %P could be a better > alternative, otherwise maybe %g, as GroupLeader/Gather?
Thanks for looking. %P is a good idea - it's consistent with ps and pkill and probably other %commands. I also amended the docs. -- Justin
>From 68a892d0023e915cc48aea1bb77eae5deabcecec Mon Sep 17 00:00:00 2001 From: Justin Pryzby <pryz...@telsasoft.com> Date: Fri, 13 Mar 2020 22:03:06 -0500 Subject: [PATCH v2] Include the leader PID in logfile See also: b025f32e0b, which adds the leader PID to pg_stat_activity --- doc/src/sgml/config.sgml | 11 ++++++- src/backend/utils/error/elog.c | 30 +++++++++++++++++++ src/backend/utils/misc/postgresql.conf.sample | 1 + 3 files changed, 41 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index b353c61683..e60403d6a5 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -6611,6 +6611,14 @@ local0.* /var/log/postgresql <entry>Process ID</entry> <entry>no</entry> </row> + <row> + <entry><literal>%P</literal></entry> + <entry>Process ID of the parallel group leader if this process was + at some point involved in parallel query, otherwise null. For a + parallel group leader itself, this field is set to its own process + ID.</entry> + <entry>no</entry> + </row> <row> <entry><literal>%t</literal></entry> <entry>Time stamp without milliseconds</entry> @@ -6943,7 +6951,7 @@ log_line_prefix = '%m [%p] %q%u@%d/%a ' character count of the error position therein, location of the error in the PostgreSQL source code (if <varname>log_error_verbosity</varname> is set to <literal>verbose</literal>), - application name, and backend type. + application name, backend type, and leader PID. Here is a sample table definition for storing CSV-format log output: <programlisting> @@ -6973,6 +6981,7 @@ CREATE TABLE postgres_log location text, application_name text, backend_type text, + leader_pid integer, PRIMARY KEY (session_id, session_line_num) ); </programlisting> diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c index e4b717c79a..dea098faf1 100644 --- a/src/backend/utils/error/elog.c +++ b/src/backend/utils/error/elog.c @@ -77,6 +77,7 @@ #include "postmaster/syslogger.h" #include "storage/ipc.h" #include "storage/proc.h" +#include "storage/procarray.h" #include "tcop/tcopprot.h" #include "utils/guc.h" #include "utils/memutils.h" @@ -2448,6 +2449,25 @@ log_line_prefix(StringInfo buf, ErrorData *edata) else appendStringInfo(buf, "%d", MyProcPid); break; + + case 'P': + if (MyProc) + { + PGPROC *leader = MyProc->lockGroupLeader; + if (leader == NULL) + /* padding only */ + appendStringInfoSpaces(buf, + padding > 0 ? padding : -padding); + else if (padding != 0) + appendStringInfo(buf, "%*d", padding, leader->pid); + else + appendStringInfo(buf, "%d", leader->pid); + } + else if (padding != 0) + appendStringInfoSpaces(buf, + padding > 0 ? padding : -padding); + break; + case 'l': if (padding != 0) appendStringInfo(buf, "%*ld", padding, log_line_number); @@ -2836,6 +2856,16 @@ write_csvlog(ErrorData *edata) else appendCSVLiteral(&buf, GetBackendTypeDesc(MyBackendType)); + appendStringInfoChar(&buf, ','); + + /* leader PID */ + if (MyProc) + { + PGPROC *leader = MyProc->lockGroupLeader; + if (leader) + appendStringInfo(&buf, "%d", leader->pid); + } + appendStringInfoChar(&buf, '\n'); /* If in the syslogger process, try to write messages direct to file */ diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index e430e33c7b..48a50fb394 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -533,6 +533,7 @@ # %h = remote host # %b = backend type # %p = process ID + # %P = leader PID # %t = timestamp without milliseconds # %m = timestamp with milliseconds # %n = timestamp with milliseconds (as a Unix epoch) -- 2.17.0