On Wed, Jun 11, 2014 at 11:55 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> Andres Freund <and...@2ndquadrant.com> writes:
>> Your wish just seems like a separate feature to me. Including
>> replication commands in 'all' seems correct independent of the desire
>> for a more granular control.
>
> No, I think I've got to vote with the other side on that.
>
> The reason we can have log_statement as a scalar progression
> "none < ddl < mod < all" is that there's little visible use-case
> for logging DML but not DDL, nor for logging SELECTS but not
> INSERT/UPDATE/DELETE. However, logging replication commands seems
> like something people would reasonably want an orthogonal control for.
> There's no nice way to squeeze such a behavior into log_statement.
>
> I guess you could say that log_statement treats replication commands
> as if they were DDL, but is that really going to satisfy users?
>
> I think we should consider log_statement to control logging of
> SQL only, and invent a separate GUC (or, in the future, likely
> more than one GUC?) for logging of replication activity.
Seems reasonable. OK. The attached patch adds log_replication_command
parameter which causes replication commands to be logged. I added this to
next CF.
Regards,
--
Fujii Masao
From 9874e36a8f65667d1f4d3a9a8d1d87d2d20f5188 Mon Sep 17 00:00:00 2001
From: MasaoFujii <masao.fu...@gmail.com>
Date: Thu, 12 Jun 2014 19:32:00 +0900
Subject: [PATCH] Add log_replication_command configuration parameter.
This GUC causes replication commands like IDENTIFY_SYSTEM
to be logged in the server log.
---
doc/src/sgml/config.sgml | 16 ++++++++++++++++
src/backend/replication/walsender.c | 11 +++++++++--
src/backend/utils/misc/guc.c | 9 +++++++++
src/backend/utils/misc/postgresql.conf.sample | 1 +
src/include/replication/walsender.h | 1 +
5 files changed, 36 insertions(+), 2 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 697cf99..8532f08 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -4534,6 +4534,22 @@ FROM pg_stat_activity;
</listitem>
</varlistentry>
+ <varlistentry id="guc-log-replication-command" xreflabel="log_replication_command">
+ <term><varname>log_replication_command</varname> (<type>boolean</type>)
+ <indexterm>
+ <primary><varname>log_replication_command</> configuration parameter</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Causes each replication command to be logged in the server log.
+ See <xref linkend="protocol-replication"> for more information about
+ replication command. The default value is <literal>off</>.
+ Only superusers can change this setting.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry id="guc-log-temp-files" xreflabel="log_temp_files">
<term><varname>log_temp_files</varname> (<type>integer</type>)
<indexterm>
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 088ee2c..009ad92 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -108,6 +108,7 @@ bool am_db_walsender = false; /* Connected to a database? */
int max_wal_senders = 0; /* the maximum number of concurrent walsenders */
int wal_sender_timeout = 60 * 1000; /* maximum time to send one
* WAL data message */
+bool log_replication_command = false;
/*
* State for WalSndWakeupRequest
@@ -1261,13 +1262,19 @@ exec_replication_command(const char *cmd_string)
MemoryContext old_context;
/*
+ * Log replication command if log_replication_command is enabled.
+ * Even when it's disabled, log the command with DEBUG1 level for
+ * backward compatibility.
+ */
+ ereport(log_replication_command ? LOG : DEBUG1,
+ (errmsg("received replication command: %s", cmd_string)));
+
+ /*
* CREATE_REPLICATION_SLOT ... LOGICAL exports a snapshot until the next
* command arrives. Clean up the old stuff if there's anything.
*/
SnapBuildClearExportedSnapshot();
- elog(DEBUG1, "received replication command: %s", cmd_string);
-
CHECK_FOR_INTERRUPTS();
cmd_context = AllocSetContextCreate(CurrentMemoryContext,
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 1d094f0..427af79 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -931,6 +931,15 @@ static struct config_bool ConfigureNamesBool[] =
NULL, NULL, NULL
},
{
+ {"log_replication_command", PGC_SUSET, LOGGING_WHAT,
+ gettext_noop("Logs each replication command."),
+ NULL
+ },
+ &log_replication_command,
+ false,
+ NULL, NULL, NULL
+ },
+ {
{"debug_assertions", PGC_USERSET, DEVELOPER_OPTIONS,
gettext_noop("Turns on various assertion checks."),
gettext_noop("This is a debugging aid."),
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index d109394..70d86cf 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -431,6 +431,7 @@
# e.g. '<%u%%%d> '
#log_lock_waits = off # log lock waits >= deadlock_timeout
#log_statement = 'none' # none, ddl, mod, all
+#log_replication_command = off
#log_temp_files = -1 # log temporary files equal or larger
# than the specified size in kilobytes;
# -1 disables, 0 logs all temp files
diff --git a/src/include/replication/walsender.h b/src/include/replication/walsender.h
index cff2be6..0095bde 100644
--- a/src/include/replication/walsender.h
+++ b/src/include/replication/walsender.h
@@ -25,6 +25,7 @@ extern bool wake_wal_senders;
/* user-settable parameters */
extern int max_wal_senders;
extern int wal_sender_timeout;
+extern bool log_replication_command;
extern void InitWalSender(void);
extern void exec_replication_command(const char *query_string);
--
1.7.1
--
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