On Tue, Jul 28, 2020 at 10:10:33AM +0900, Michael Paquier wrote:
> Except for those nits, I have tested the patch and things behave as we
> want (including padding and docs), so this looks good to me.
Revised with your suggestions.
--
Justin
>From 72184bdb83eba6e477a12b743bb8d6bf938c5f41 Mon Sep 17 00:00:00 2001
From: Justin Pryzby <pryz...@telsasoft.com>
Date: Fri, 13 Mar 2020 22:03:06 -0500
Subject: [PATCH v4] Include the leader PID in logfile
See also: b025f32e0b, which added the leader PID to pg_stat_activity
---
doc/src/sgml/config.sgml | 10 ++++++-
src/backend/utils/error/elog.c | 30 +++++++++++++++++++
src/backend/utils/misc/postgresql.conf.sample | 1 +
3 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 994155ca00..89dd19035c 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -6694,6 +6694,13 @@ local0.* /var/log/postgresql
<entry>Process ID</entry>
<entry>no</entry>
</row>
+ <row>
+ <entry><literal>%P</literal></entry>
+ <entry>For a parallel worker, this is the Process ID of its leader
+ process.
+ </entry>
+ <entry>no</entry>
+ </row>
<row>
<entry><literal>%t</literal></entry>
<entry>Time stamp without milliseconds</entry>
@@ -7026,7 +7033,7 @@ 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>
@@ -7056,6 +7063,7 @@ 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..3055b72c01 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 || leader->pid == MyProcPid)
+ /* 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 && leader->pid != MyProcPid)
+ 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 b0715ae188..1ecdfc51a6 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -537,6 +537,7 @@
# %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
