Here is a documentation update from Liudmila Mantrova.

--
Alexander Kuzmenkov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company

diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml
index 4a68ec3..5bd7b45 100644
--- a/doc/src/sgml/maintenance.sgml
+++ b/doc/src/sgml/maintenance.sgml
@@ -932,8 +932,8 @@ analyze threshold = analyze base threshold + analyze scale factor * number of tu
    program if you have one that you are already using with other
    server software. For example, the <application>rotatelogs</application>
    tool included in the <productname>Apache</productname> distribution
-   can be used with <productname>PostgreSQL</productname>.  To do this,
-   just pipe the server's
+   can be used with <productname>PostgreSQL</productname>. One way to 
+   do this is to pipe the server's
    <systemitem>stderr</systemitem> output to the desired program.
    If you start the server with
    <command>pg_ctl</command>, then <systemitem>stderr</systemitem>
@@ -946,6 +946,36 @@ pg_ctl start | rotatelogs /var/log/pgsql_log 86400
   </para>
 
   <para>
+   You can combine these approaches by setting up <application>logrotate</application>
+   to collect log files produced by <productname>PostgreSQL</productname> built-in logging
+   collector. In this case, the logging collector defines the names and
+   location of the log files, while <application>logrotate</application>
+   periodically archives these files. When initiating log rotation,
+   <application>logrotate</application> must ensure that the application
+   sends further output to the new file. This is commonly done with a
+   <literal>postrotate</literal> script that sends a <literal>SIGHUP</literal> signal to
+   the application, which then reopens the log file.
+   In <productname>PostgreSQL</productname>, you can run <application>pg_ctl</application>
+   with the <literal>logrotate</literal> option instead. When the server receives
+   this command, the server either switches to a new log file or reopens the
+   existing file, depending on the logging configuration
+   (see <xref linkend="runtime-config-logging-where"/>).
+  </para>
+
+  <note>
+   <para>
+    When using static log file names, the server might fail to reopen the log
+    file if the max open file limit is reached or a file table overflow occurs.
+    In this case, log messages are sent to the old log file until a
+    successful log rotation. If <application>logrotate</application> is
+    configured to compress the log file and delete it, the server may lose
+    the messages logged in this timeframe. To avoid this issue, you can
+    configure the logging collector to dynamically assign log file names
+    and use a <literal>prerotate</literal> script to ignore open log files.
+    </para>
+  </note>
+
+  <para>
    Another production-grade approach to managing log output is to
    send it to <application>syslog</application> and let
    <application>syslog</application> deal with file rotation. To do this, set the
@@ -958,7 +988,6 @@ pg_ctl start | rotatelogs /var/log/pgsql_log 86400
    configured to work with log files from
    <application>syslog</application>.
   </para>
-
   <para>
    On many systems, however, <application>syslog</application> is not very reliable,
    particularly with large log messages; it might truncate or drop messages
diff --git a/doc/src/sgml/ref/pg_ctl-ref.sgml b/doc/src/sgml/ref/pg_ctl-ref.sgml
index 0816bc1..235c8ba 100644
--- a/doc/src/sgml/ref/pg_ctl-ref.sgml
+++ b/doc/src/sgml/ref/pg_ctl-ref.sgml
@@ -102,6 +102,12 @@ PostgreSQL documentation
    <arg choice="plain"><option>kill</option></arg>
    <arg choice="plain"><replaceable>signal_name</replaceable></arg>
    <arg choice="plain"><replaceable>process_id</replaceable></arg>
+  </cmdsynopsis>  
+
+  <cmdsynopsis>
+   <command>pg_ctl</command>
+   <arg choice="plain"><option>logrotate</option></arg>
+   <arg choice="opt"><option>-D</option> <replaceable>datadir</replaceable></arg>
   </cmdsynopsis>
 
   <para>On Microsoft Windows, also:</para>
@@ -234,6 +240,12 @@ PostgreSQL documentation
   </para>
 
   <para>
+   <option>logrotate</option> mode rotates the server log file.
+   For details on how to use this mode with external log rotation tools, see
+   <xref linkend="logfile-maintenance"/>.
+  </para>
+
+  <para>
    <option>register</option> mode registers the <productname>PostgreSQL</productname>
    server as a system service on <productname>Microsoft Windows</productname>.
    The <option>-S</option> option allows selection of service start type,
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index a4b53b3..e7e779e 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -385,6 +385,9 @@ static bool LoadedSSL = false;
 static DNSServiceRef bonjour_sdref = NULL;
 #endif
 
+/* Log rotation signal file path, relative to $PGDATA */
+#define LOGROTATE_SIGNAL_FILE	"logrotate"
+
 /*
  * postmaster.c - function prototypes
  */
@@ -398,6 +401,7 @@ static void reset_shared(int port);
 static void SIGHUP_handler(SIGNAL_ARGS);
 static void pmdie(SIGNAL_ARGS);
 static void reaper(SIGNAL_ARGS);
+static bool checkLogrotateSignal(void);
 static void sigusr1_handler(SIGNAL_ARGS);
 static void startup_die(SIGNAL_ARGS);
 static void dummy_handler(SIGNAL_ARGS);
@@ -5003,6 +5007,24 @@ ExitPostmaster(int status)
 }
 
 /*
+ * Check to see if a log rotation request has arrived. Should be
+ * called by postmaster after receiving SIGUSR1.
+ */
+static bool
+checkLogrotateSignal(void)
+{
+	struct stat stat_buf;
+
+	if (stat(LOGROTATE_SIGNAL_FILE, &stat_buf) == 0)
+	{
+		unlink(LOGROTATE_SIGNAL_FILE);
+		return true;
+	}
+
+	return false;
+}
+
+/*
  * sigusr1_handler - handle signal conditions from child processes
  */
 static void
@@ -5100,7 +5122,8 @@ sigusr1_handler(SIGNAL_ARGS)
 		signal_child(PgArchPID, SIGUSR1);
 	}
 
-	if (CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE) &&
+	if ((checkLogrotateSignal() ||
+		 CheckPostmasterSignal(PMSIGNAL_ROTATE_LOGFILE)) &&
 		SysLoggerPID != 0)
 	{
 		/* Tell syslogger to rotate logfile */
diff --git a/src/backend/postmaster/syslogger.c b/src/backend/postmaster/syslogger.c
index 58b759f..41f036f 100644
--- a/src/backend/postmaster/syslogger.c
+++ b/src/backend/postmaster/syslogger.c
@@ -388,7 +388,7 @@ SysLoggerMain(int argc, char *argv[])
 		{
 			/*
 			 * Force rotation when both values are zero. It means the request
-			 * was sent by pg_rotate_logfile.
+			 * was sent by pg_rotate_logfile or pg_ctl logrotate.
 			 */
 			if (!time_based_rotation && size_rotation_for == 0)
 				size_rotation_for = LOG_DESTINATION_STDERR | LOG_DESTINATION_CSVLOG;
diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index ed2396a..71792ed 100644
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -59,6 +59,7 @@ typedef enum
 	STOP_COMMAND,
 	RESTART_COMMAND,
 	RELOAD_COMMAND,
+	LOGROTATE_COMMAND,
 	STATUS_COMMAND,
 	PROMOTE_COMMAND,
 	KILL_COMMAND,
@@ -100,6 +101,7 @@ static char version_file[MAXPGPATH];
 static char pid_file[MAXPGPATH];
 static char backup_file[MAXPGPATH];
 static char promote_file[MAXPGPATH];
+static char logrotate_file[MAXPGPATH];
 
 #ifdef WIN32
 static DWORD pgctl_start_type = SERVICE_AUTO_START;
@@ -125,6 +127,7 @@ static void do_restart(void);
 static void do_reload(void);
 static void do_status(void);
 static void do_promote(void);
+static void do_logrotate(void);
 static void do_kill(pgpid_t pid);
 static void print_msg(const char *msg);
 static void adjust_data_dir(void);
@@ -1171,6 +1174,62 @@ do_promote(void)
 		print_msg(_("server promoting\n"));
 }
 
+/*
+ * log rotate
+ */
+
+static void
+do_logrotate(void)
+{
+	FILE	   *logrotatefile;
+	pgpid_t		pid;
+
+	pid = get_pgpid(false);
+
+	if (pid == 0)				/* no pid file */
+	{
+		write_stderr(_("%s: PID file \"%s\" does not exist\n"), progname, pid_file);
+		write_stderr(_("Is server running?\n"));
+		exit(1);
+	}
+	else if (pid < 0)			/* standalone backend, not postmaster */
+	{
+		pid = -pid;
+		write_stderr(_("%s: cannot rotate log file; "
+					   "single-user server is running (PID: %ld)\n"),
+					 progname, pid);
+		exit(1);
+	}
+
+	snprintf(logrotate_file, MAXPGPATH, "%s/logrotate", pg_data);
+
+	if ((logrotatefile = fopen(logrotate_file, "w")) == NULL)
+	{
+		write_stderr(_("%s: could not create log rotation signal file \"%s\": %s\n"),
+					 progname, logrotate_file, strerror(errno));
+		exit(1);
+	}
+	if (fclose(logrotatefile))
+	{
+		write_stderr(_("%s: could not write log rotation signal file \"%s\": %s\n"),
+					 progname, logrotate_file, strerror(errno));
+		exit(1);
+	}
+
+	sig = SIGUSR1;
+	if (kill((pid_t) pid, sig) != 0)
+	{
+		write_stderr(_("%s: could not send log rotation signal (PID: %ld): %s\n"),
+					 progname, pid, strerror(errno));
+		if (unlink(logrotate_file) != 0)
+			write_stderr(_("%s: could not remove log rotation signal file \"%s\": %s\n"),
+						 progname, logrotate_file, strerror(errno));
+		exit(1);
+	}
+
+	print_msg(_("commanded to rotate log file\n"));
+}
+
 
 /*
  *	utility routines
@@ -2333,6 +2392,8 @@ main(int argc, char **argv)
 				ctl_command = RESTART_COMMAND;
 			else if (strcmp(argv[optind], "reload") == 0)
 				ctl_command = RELOAD_COMMAND;
+			else if (strcmp(argv[optind], "logrotate") == 0)
+				ctl_command = LOGROTATE_COMMAND;
 			else if (strcmp(argv[optind], "status") == 0)
 				ctl_command = STATUS_COMMAND;
 			else if (strcmp(argv[optind], "promote") == 0)
@@ -2443,6 +2504,9 @@ main(int argc, char **argv)
 		case PROMOTE_COMMAND:
 			do_promote();
 			break;
+		case LOGROTATE_COMMAND:
+			do_logrotate();
+			break;
 		case KILL_COMMAND:
 			do_kill(killproc);
 			break;

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