doc: note downstream node (dis)connection monitoring in more places

This is for backbranches to prevent them running against newer
PostgreSQL versions with which they are not compatible, for example
4.4.x with PostgreSQL 12 and later.

HISTORY

@@ -1,4 +1,8 @@
-4.4     2019-??-??
+4.4.1   2019-??-??
+        repmgr: improve data directory check (Ian)
+        repmgr: improve extension check during "standby clone" (Ian)
+
+4.4     2019-06-27
         repmgr: improve "daemon status" output (Ian)
         repmgr: add "--siblings-follow" option to "standby promote" (Ian)
         repmgr: add "--repmgrd-force-unpause" option to "standby switchover" (Ian)
@@ -6,6 +10,8 @@
           an existing directory is being overwritten (Ian)
         repmgr: improve "--dry-run" behaviour for "standby promote" and
           "standby switchover" (Ian)
+        repmgr: when running "standby clone" with the "--upstream-conninfo" option
+          ensure that "application_name" is set correctly in "primary_conninfo" (Ian)
         repmgr: ensure "--dry-run" together with --force when running "standby clone"
           in barman mode does not modify an existing data directory (Ian)
         repmgr: improve "--dry-run" output when running "standby clone" in
@@ -21,6 +27,8 @@
         repmgr: prevent a witness server being registered on the cluster primary (John)
         repmgr: ensure BDR2-specific functionality cannot be used on
           BDR3 and later (Ian)
+        repmgr: canonicalize the data directory path (Ian)
+        repmgr: note that "standby follow" requires a primary to be available (Ian)
         repmgrd: monitor standbys attached to primary (Ian)
         repmgrd: add "primary visibility consensus" functionality (Ian)
         repmgrd: fix memory leak which occurs while the monitored PostgreSQL

Makefile.global.in

@@ -24,4 +24,5 @@ include $(PGXS)
 -include ${repmgr_abs_srcdir}/Makefile.custom
 
 REPMGR_VERSION=$(shell awk '/^\#define REPMGR_VERSION / { print $3; }' ${repmgr_abs_srcdir}/repmgr_version.h.in | cut -d '"' -f 2)
+REPMGR_RELEASE_DATE=$(shell awk '/^\#define REPMGR_RELEASE_DATE / { print $3; }' ${repmgr_abs_srcdir}/repmgr_version.h.in | cut -d '"' -f 2)
 

configfile.c

@@ -502,10 +502,15 @@ _parse_config(t_configuration_options *options, ItemList *error_list, ItemList *
 		else if (strcmp(name, "conninfo") == 0)
 			strncpy(options->conninfo, value, MAXLEN);
 		else if (strcmp(name, "data_directory") == 0)
+		{
 			strncpy(options->data_directory, value, MAXPGPATH);
+			canonicalize_path(options->data_directory);
+		}
 		else if (strcmp(name, "config_directory") == 0)
+		{
 			strncpy(options->config_directory, value, MAXPGPATH);
-
+			canonicalize_path(options->config_directory);
+		}
 		else if (strcmp(name, "replication_user") == 0)
 		{
 			if (strlen(value) < sizeof(options->replication_user))

dbutils.c

@@ -336,12 +336,10 @@ establish_db_connection_by_params(t_conninfo_param_list *param_list,
 bool
 is_superuser_connection(PGconn *conn, t_connection_user *userinfo)
 {
-	char	   *current_user = NULL;
-	const char *superuser_status = NULL;
 	bool		is_superuser = false;
+	const char *current_user = PQuser(conn);
+	const char *superuser_status = PQparameterStatus(conn, "is_superuser");
 
-	current_user = PQuser(conn);
-	superuser_status = PQparameterStatus(conn, "is_superuser");
 	is_superuser = (strcmp(superuser_status, "on") == 0) ? true : false;
 
 	if (userinfo != NULL)
@@ -356,6 +354,51 @@ is_superuser_connection(PGconn *conn, t_connection_user *userinfo)
 }
 
 
+bool
+connection_has_pg_settings(PGconn *conn)
+{
+	bool		has_pg_settings = false;
+
+	/* superusers can always read pg_settings */
+	if (is_superuser_connection(conn, NULL) == true)
+	{
+		has_pg_settings = true;
+	}
+	/* from PostgreSQL 10, a non-superuser may have been granted access */
+	else if(PQserverVersion(conn) >= 100000)
+	{
+		PQExpBufferData query;
+		PGresult   *res;
+
+		initPQExpBuffer(&query);
+		appendPQExpBufferStr(&query,
+							 "  SELECT CASE "
+							 "           WHEN pg_catalog.pg_has_role('pg_monitor','MEMBER') "
+							 "             THEN TRUE "
+							 "           WHEN pg_catalog.pg_has_role('pg_read_all_settings','MEMBER') "
+							 "             THEN TRUE "
+							 "           ELSE FALSE "
+							 "         END AS has_pg_settings");
+
+		res = PQexec(conn, query.data);
+
+		if (PQresultStatus(res) != PGRES_TUPLES_OK)
+		{
+			log_db_error(conn, query.data,
+						 _("connection_has_pg_settings(): unable to query user roles"));
+		}
+		else
+		{
+			has_pg_settings = atobool(PQgetvalue(res, 0, 0));
+		}
+		termPQExpBuffer(&query);
+		PQclear(res);
+	}
+
+	return has_pg_settings;
+}
+
+
 void
 close_connection(PGconn **conn)
 {
@@ -1865,8 +1908,20 @@ repmgrd_set_pid(PGconn *conn, pid_t repmgrd_pid, const char *pidfile)
 	initPQExpBuffer(&query);
 
 	appendPQExpBuffer(&query,
-					  "SELECT repmgr.set_repmgrd_pid(%i, '%s')",
-					  (int) repmgrd_pid, pidfile);
+					  "SELECT repmgr.set_repmgrd_pid(%i, ",
+					  (int) repmgrd_pid);
+
+	if (pidfile != NULL)
+	{
+		appendPQExpBuffer(&query,
+						  " '%s')",
+						  pidfile);
+	}
+	else
+	{
+		appendPQExpBufferStr(&query,
+							 " '')");
+	}
 
 	res = PQexec(conn, query.data);
 	termPQExpBuffer(&query);
@@ -2092,9 +2147,9 @@ get_repmgr_extension_status(PGconn *conn, t_extension_versions *extversions)
 	appendPQExpBufferStr(&query,
 						 "	  SELECT ae.name, e.extname, "
 						 "           ae.default_version, "
-						 "           (((ae.default_version::NUMERIC::INT) * 10000) + (ae.default_version::NUMERIC - ae.default_version::NUMERIC::INT) * 1000)::INT AS available, "
+						 "           (((FLOOR(ae.default_version::NUMERIC)::INT) * 10000) + (ae.default_version::NUMERIC - FLOOR(ae.default_version::NUMERIC)::INT) * 1000)::INT AS available, "
 						 "           ae.installed_version, "
-						 "           (((ae.installed_version::NUMERIC::INT) * 10000) + (ae.installed_version::NUMERIC - ae.installed_version::NUMERIC::INT) * 1000)::INT AS installed "
+						 "           (((FLOOR(ae.installed_version::NUMERIC)::INT) * 10000) + (ae.installed_version::NUMERIC - FLOOR(ae.installed_version::NUMERIC)::INT) * 1000)::INT AS installed "
 						 "     FROM pg_catalog.pg_available_extensions ae "
 						 "LEFT JOIN pg_catalog.pg_extension e "
 						 "       ON e.extname=ae.name "
@@ -5073,6 +5128,7 @@ init_replication_info(ReplInfo *replication_info)
 	replication_info->receiving_streamed_wal = true;
 	replication_info->wal_replay_paused = false;
 	replication_info->upstream_last_seen = -1;
+	replication_info->upstream_node_id = UNKNOWN_NODE_ID;
 }
 
 

dbutils.h

@@ -438,6 +438,7 @@ PGconn	   *get_primary_connection(PGconn *standby_conn, int *primary_id, char *p
 PGconn	   *get_primary_connection_quiet(PGconn *standby_conn, int *primary_id, char *primary_conninfo_out);
 
 bool		is_superuser_connection(PGconn *conn, t_connection_user *userinfo);
+bool		connection_has_pg_settings(PGconn *conn);
 void		close_connection(PGconn **conn);
 
 /* conninfo manipulation functions */

doc/Makefile

@@ -31,6 +31,7 @@ ALLXML := $(wildcard $(srcdir)/*.xml) $(GENERATED_XML)
 version.xml: $(repmgr_top_builddir)/repmgr_version.h
 	{ \
 	  echo "<!ENTITY repmgrversion \"$(REPMGR_VERSION)\">"; \
+	  echo "<!ENTITY releasedate \"$(REPMGR_RELEASE_DATE)\">"; \
 	} > $@
 
 ##

doc/appendix-release-notes.xml

@@ -16,8 +16,36 @@
   </para>
 
   <sect1 id="release-4.4">
-    <title>Release 4.4</title>
-    <para><emphasis>?? June, 2019</emphasis></para>
+    <title id="release-current">Release 4.4</title>
+    <para><emphasis>27 June, 2019</emphasis></para>
+
+    <para>
+      &repmgr; 4.4 is a major release.
+    </para>
+    <para>
+      For details on how to upgrade an existing &repmgr; instrallation, see
+      documentation section <link linkend="upgrading-major-version">Upgrading a major version release</link>.
+    </para>
+    <para>
+      If &repmgrd; is in use, a PostgreSQL restart <emphasis>is</emphasis> required;
+      in that case we suggest combining this &repmgr; upgrade with the next PostgreSQL
+      minor release, which will require a PostgreSQL restart in any case.
+    </para>
+
+
+    <important>
+      <para>
+        On Debian-based systems, including Ubuntu, if using &repmgrd;
+        please ensure that in the file <filename>/etc/init.d/repmgrd</filename>, the parameter
+        <varname>REPMGRD_OPTS</varname> contains &quot;<literal>--daemonize=false</literal>&quot;, e.g.:
+        <programlisting>
+# additional options
+REPMGRD_OPTS="--daemonize=false"</programlisting>
+      </para>
+      <para>
+        For further details, see <link linkend="repmgrd-configuration-debian-ubuntu">repmgrd configuration on Debian/Ubuntu</link>.
+      </para>
+    </important>
 
     <sect2>
       <title>repmgr client enhancements</title>
@@ -43,6 +71,14 @@
             </para>
           </listitem>
 
+          <listitem>
+            <para>
+              <link linkend="repmgr-standby-follow"><command>repmgr standby follow</command></link>:
+              note that an active, reachable cluster primary is required for this command;
+              and provide a more helpful error message if no reachable primary could be found.
+            </para>
+          </listitem>
+
           <listitem>
             <para>
               &repmgr;: when executing <link linkend="repmgr-standby-switchover"><command>repmgr standby switchover</command></link>,
@@ -75,7 +111,6 @@
             </para>
           </listitem>
 
-
           <listitem>
             <para>
               <link linkend="repmgr-standby-promote"><command>repmgr standby promote</command></link>:
@@ -163,7 +198,7 @@
               execute a custom script.
             </para>
             <para>
-              This provided an additional method for fencing an isolated primary node, and/or taking
+              This provides an additional method for fencing an isolated primary node, and/or taking
               other action if one or more standys become disconnected.
             </para>
             <para>
@@ -221,6 +256,14 @@
             </para>
           </listitem>
 
+          <listitem>
+            <para>
+              &repmgr;: when executing <link linkend="repmgr-standby-clone"><command>repmgr standby clone</command></link>
+              with the <option>--upstream-conninfo</option>, ensure that <varname>application_name</varname>
+              is set correctly in <varname>primary_conninfo</varname>.
+            </para>
+          </listitem>
+
           <listitem>
             <para>
               &repmgr;: when executing <link linkend="repmgr-standby-switchover"><command>repmgr standby switchover</command></link>,
@@ -229,6 +272,16 @@
             </para>
           </listitem>
 
+          <listitem>
+            <para>
+              &repmgr;: canonicalize the data directory path when parsing the configuration file, so
+              the provided path matches the path PostgreSQL reports as its data directory.
+              Otherwise, if e.g. the data directory is configured with a trailing slash,
+              <link linkend="repmgr-node-check"><command>repmgr node check --data-directory-config</command></link>
+              will return a spurious error.
+            </para>
+          </listitem>
+
           <listitem>
             <para>
               &repmgrd;: fix memory leak which occurs while the monitored PostgreSQL node is <emphasis>not</emphasis>

doc/cloning-standbys.xml

@@ -52,6 +52,24 @@
    </itemizedlist>
    </para>
 
+
+   <note>
+    <para>
+      Currently &repmgr;'s support for cloning from Barman is implemented by using
+      <productname>rsync</productname> to clone from the Barman server.
+    </para>
+    <para>
+      It is therefore not able to make use of Barman's parallel restore facility, which
+      is executed on the Barman server and clones to the target server.
+    </para>
+    <para>
+      Barman's parallel restore facility can be used by executing it manually on
+      the Barman server and integrating the resulting cloned standby using
+      <command><link linkend="repmgr-standby-clone">repmgr standby clone --recovery-conf-only</link></command>.
+    </para>
+   </note>
+
+
   <sect2 id="cloning-from-barman-prerequisites">
    <title>Prerequisites for cloning from Barman</title>
    <para>
@@ -60,8 +78,7 @@
    <itemizedlist spacing="compact" mark="bullet">
      <listitem>
       <para>
-        the <varname>barman_server</varname> setting in <filename>repmgr.conf</filename> is the same as the
-        server configured in Barman;
+        the Barman catalogue must include at least one valid backup for this server;
       </para>
      </listitem>
      <listitem>
@@ -72,19 +89,68 @@
      </listitem>
      <listitem>
       <para>
-        the <varname>restore_command</varname> setting in <filename>repmgr.conf</filename> is configured to
-        use a copy of the <command>barman-wal-restore</command> script shipped with the
-        <literal>barman-cli</literal> package (see section <xref linkend="cloning-from-barman-restore-command"/>
-        below).
-      </para>
-     </listitem>
-     <listitem>
-      <para>
-        the Barman catalogue includes at least one valid backup for this  server.
+        the <varname>barman_server</varname> setting in <filename>repmgr.conf</filename> is the same as the
+        server configured in Barman.
       </para>
      </listitem>
+
    </itemizedlist>
    </para>
+
+   <para>
+     For example, assuming Barman is located on the host &quot;<literal>barmansrv</literal>&quot;
+     under the &quot;<literal>barman</literal>&quot; user account,
+     <filename>repmgr.conf</filename> should contain the following entries:
+    <programlisting>
+    barman_host=barman@barmansrv
+    barman_server=somedb</programlisting>
+   </para>
+
+   <note>
+    <para>
+     To use a non-default Barman configuration file on the Barman server,
+     specify this in <filename>repmgr.conf</filename> with <filename>barman_config</filename>:
+     <programlisting>
+      barman_config=/path/to/barman.conf</programlisting>
+    </para>
+   </note>
+
+
+   <para>
+     We also recommend configuring the <varname>restore_command</varname> setting in <filename>repmgr.conf</filename>
+     to use the <command>barman-wal-restore</command> script
+     (see section <xref linkend="cloning-from-barman-restore-command"/> below).
+   </para>
+
+
+   <tip>
+    <simpara>
+      If you have a non-default SSH configuration on the Barman
+      server, e.g. using a port other than 22, then you can set those
+      parameters in a dedicated Host section in <filename>~/.ssh/config</filename>
+      corresponding to the value of <varname>barman_host</varname> in
+      <filename>repmgr.conf</filename>. See the <literal>Host</literal>
+      section in <command>man 5 ssh_config</command> for more details.
+    </simpara>
+   </tip>
+   <para>
+    It's now possible to clone a standby from Barman, e.g.:
+    <programlisting>
+    $ repmgr -f /etc/repmgr.conf -h node1 -U repmgr -d repmgr standby clone
+    NOTICE: destination directory "/var/lib/postgresql/data" provided
+    INFO: connecting to Barman server to verify backup for "test_cluster"
+    INFO: checking and correcting permissions on existing directory "/var/lib/postgresql/data"
+    INFO: creating directory "/var/lib/postgresql/data/repmgr"...
+    INFO: connecting to Barman server to fetch server parameters
+    INFO: connecting to source node
+    DETAIL: current installation size is 30 MB
+    NOTICE: retrieving backup from Barman...
+    (...)
+    NOTICE: standby clone (from Barman) complete
+    NOTICE: you can now start your PostgreSQL server
+    HINT: for example: pg_ctl -D /var/lib/postgresql/data start</programlisting>
+   </para>
+
    <note>
     <simpara>
      Barman support is automatically enabled if <varname>barman_server</varname>
@@ -94,37 +160,7 @@
      command line option.
     </simpara>
    </note>
-   <tip>
-    <simpara>
-      If you have a non-default SSH configuration on the Barman
-      server, e.g. using a port other than 22, then you can set those
-      parameters in a dedicated Host section in <filename>~/.ssh/config</filename>
-      corresponding to the value of<varname>barman_host</varname> in
-      <filename>repmgr.conf</filename>. See the <literal>Host</literal>
-      section in <command>man 5 ssh_config</command> for more details.
-    </simpara>
-   </tip>
-   <para>
-    It's now possible to clone a standby from Barman, e.g.:
-    <programlisting>
-    NOTICE: using configuration file "/etc/repmgr.conf"
-    NOTICE: destination directory "/var/lib/postgresql/data" provided
-    INFO: connecting to Barman server to verify backup for test_cluster
-    INFO: checking and correcting permissions on existing directory "/var/lib/postgresql/data"
-    INFO: creating directory "/var/lib/postgresql/data/repmgr"...
-    INFO: connecting to Barman server to fetch server parameters
-    INFO: connecting to upstream node
-    INFO: connected to source node, checking its state
-    INFO: successfully connected to source node
-    DETAIL: current installation size is 29 MB
-    NOTICE: retrieving backup from Barman...
-    receiving file list ...
-    (...)
-    NOTICE: standby clone (from Barman) complete
-    NOTICE: you can now start your PostgreSQL server
-    HINT: for example: pg_ctl -D /var/lib/postgresql/data start</programlisting>
 
-   </para>
   </sect2>
   <sect2 id="cloning-from-barman-restore-command" xreflabel="Using Barman as a WAL file source">
    <title>Using Barman as a WAL file source</title>
@@ -142,35 +178,28 @@
    </para>
    <para>
      <command>barman-wal-restore</command> is a Python script provided as part of the <literal>barman-cli</literal>
-     package (Barman 2.0 and later; for Barman 1.x the script is provided separately as
-     <command>barman-wal-restore.py</command>) which performs this function for Barman.
+     package (Barman 2.0 ~ 2.7) or as part of the core Barman distribution (Barman 2.8 and later).
    </para>
    <para>
-    To use <command>barman-wal-restore</command> with &repmgr;
-    and assuming Barman is located on the <literal>barmansrv</literal> host
+    To use <command>barman-wal-restore</command> with &repmgr;,
+    assuming Barman is located on the host &quot;<literal>barmansrv</literal>&quot;
+    under the &quot;<literal>barman</literal>&quot; user account,
     and that <command>barman-wal-restore</command> is located as an executable at
     <filename>/usr/bin/barman-wal-restore</filename>,
     <filename>repmgr.conf</filename> should include the following lines:
     <programlisting>
-    barman_host=barmansrv
+    barman_host=barman@barmansrv
     barman_server=somedb
     restore_command=/usr/bin/barman-wal-restore barmansrv somedb %f %p</programlisting>
    </para>
    <note>
     <simpara>
       <command>barman-wal-restore</command> supports command line switches to
-      control parallelism (<literal>--parallel=N</literal>) and compression (
-      <literal>--bzip2</literal>, <literal>--gzip</literal>).
+      control parallelism (<literal>--parallel=N</literal>) and compression
+      (<literal>--bzip2</literal>, <literal>--gzip</literal>).
     </simpara>
    </note>
-   <note>
-    <para>
-     To use a non-default Barman configuration file on the Barman server,
-     specify this in <filename>repmgr.conf</filename> with <filename>barman_config</filename>:
-     <programlisting>
-      barman_config=/path/to/barman.conf</programlisting>
-    </para>
-   </note>
+
   </sect2>
  </sect1>
 

doc/configuration-file-optional-settings.xml

@@ -0,0 +1,124 @@
+<sect1 id="configuration-file-optional-settings" xreflabel="optional configuration file settings">
+
+  <title>Optional configuration file settings</title>
+
+  <indexterm>
+    <primary>repmgr.conf</primary>
+    <secondary>optional settings</secondary>
+  </indexterm>
+
+  <variablelist>
+
+
+    <varlistentry id="repmgr-conf-config-directory" xreflabel="config_directory">
+      <term><varname>config_directory</varname> (<type>string</type>)
+        <indexterm>
+          <primary><varname>config_directory</varname> configuration file parameter</primary>
+        </indexterm>
+      </term>
+      <listitem>
+        <para>
+          If PostgreSQL configuration files are located outside the data
+	  directory, specify the directory where the main
+	  <filename>postgresql.conf</filename> file is located.
+        </para>
+        <para>
+          This enables explicit provision of an external configuration file
+          directory, which if set will be passed to <command>pg_ctl</command> as the
+          <option>-D</option> parameter. Otherwise <command>pg_ctl</command> will
+          default to using the data directory, which will cause some operations
+          to fail if the configuration files are not present there.
+        </para>
+        <note>
+          <para>
+           This is implemented primarily for feature completeness and for
+           development/testing purposes. Users who have installed &repmgr; from
+           a package should <emphasis>not</emphasis> rely on  to stop/start/restart PostgreSQL,
+           instead they should set the appropriate <option>service_..._command</option>
+           for their operating system. For more details see
+           <xref linkend="configuration-file-service-commands"/>.
+          </para>
+        </note>
+      </listitem>
+    </varlistentry>
+
+    <varlistentry id="repmgr-conf-replication-user" xreflabel="replication_user">
+      <term><varname>replication_user</varname> (<type>string</type>)
+        <indexterm>
+          <primary><varname>replication_user</varname> configuration file parameter</primary>
+        </indexterm>
+      </term>
+      <listitem>
+        <para>
+          PostgreSQL user to make replication connections with.
+          If not set defaults, to the user defined in <xref linkend="repmgr-conf-conninfo"/>.
+        </para>
+      </listitem>
+    </varlistentry>
+
+
+
+    <varlistentry id="repmgr-conf-replication-type" xreflabel="replication_type">
+      <term><varname>replication_type</varname> (<type>string</type>)
+        <indexterm>
+          <primary><varname>replication_type</varname> configuration file parameter</primary>
+        </indexterm>
+      </term>
+      <listitem>
+        <para>
+          Must be one of <literal>physical</literal> (for standard streaming replication)
+          or <literal>bdr</literal>.
+        </para>
+        <note>
+          <para>
+	    Replication type <literal>bdr</literal> can only be used with BDR 2.x
+          </para>
+          <para>
+            BDR 3.x users should use <literal>physical</literal>.
+          </para>
+        </note>
+      </listitem>
+    </varlistentry>
+
+    <varlistentry id="repmgr-conf-location" xreflabel="location">
+      <term><varname>location</varname> (<type>string</type>)
+        <indexterm>
+          <primary><varname>location</varname> configuration file parameter</primary>
+        </indexterm>
+      </term>
+      <listitem>
+        <para>
+          An arbitrary string defining the location of the node; this
+	  is used during failover to check visibility of the
+	  current primary node.
+        </para>
+        <para>
+          For more details see <xref linkend="repmgrd-network-split"/>.
+        </para>
+      </listitem>
+    </varlistentry>
+
+    <varlistentry id="repmgr-conf-use-replication-slots" xreflabel="use_replication_slots">
+      <term><varname>use_replication_slots</varname> (<type>boolean</type>)
+        <indexterm>
+          <primary><varname>use_replication_slots</varname> configuration file parameter</primary>
+        </indexterm>
+      </term>
+      <listitem>
+        <para>
+          Whether to use physical replication slots.
+        </para>
+        <note>
+          <para>
+	    When using replication slots,
+	    <varname>max_replication_slots</varname> should be configured for
+	    at least the number of standbys which will connect
+	    to the primary.
+          </para>
+        </note>
+      </listitem>
+    </varlistentry>
+
+
+  </variablelist>
+</sect1>

doc/configuration-file-required-settings.xml

@@ -96,33 +96,6 @@
   </variablelist>
  </para>
 
-  <para>
-    For a full list of annotated configuration items, see the file
-    <ulink url="https://raw.githubusercontent.com/2ndQuadrant/repmgr/master/repmgr.conf.sample">repmgr.conf.sample</ulink>.
-  </para>
-  <para>
-    For &repmgrd;-specific settings, see <xref linkend="repmgrd-configuration"/>.
-  </para>
 
-  <note>
-    <para>
-    The following parameters in the configuration file can be overridden with
-    command line options:
-    <itemizedlist>
-     <listitem>
-       <simpara>
-         <literal>-L/--log-level</literal> overrides <literal>log_level</literal> in
-         <filename>repmgr.conf</filename>
-       </simpara>
-     </listitem>
-     <listitem>
-       <simpara>
-         <literal>-b/--pg_bindir</literal> overrides <literal>pg_bindir</literal> in
-         <filename>repmgr.conf</filename>
-       </simpara>
-     </listitem>
-    </itemizedlist>
-    </para>
-  </note>
 
 </sect1>

doc/configuration-file.xml

@@ -62,6 +62,70 @@ data_directory = /var/lib/pgsql/11/data</programlisting>
   </sect2>
 
 
+  <sect2 id="configuration-file-items" xreflabel="configuration file items">
+
+    <title>Configuration file items</title>
+    <para>
+      The following sections document some sections of the configuration file:
+       <itemizedlist>
+          <listitem>
+            <simpara>
+              <xref linkend="configuration-file-settings"/>
+            </simpara>
+          </listitem>
+
+          <listitem>
+            <simpara>
+              <xref linkend="configuration-file-optional-settings"/>
+            </simpara>
+          </listitem>
+
+          <listitem>
+            <simpara>
+              <xref linkend="configuration-file-log-settings"/>
+            </simpara>
+          </listitem>
+
+
+          <listitem>
+            <simpara>
+              <xref linkend="configuration-file-service-commands"/>
+            </simpara>
+          </listitem>
+
+       </itemizedlist>
+
+    </para>
+    <para>
+      For a full list of annotated configuration items, see the file
+      <ulink url="https://raw.githubusercontent.com/2ndQuadrant/repmgr/master/repmgr.conf.sample">repmgr.conf.sample</ulink>.
+    </para>
+    <para>
+      For &repmgrd;-specific settings, see <xref linkend="repmgrd-configuration"/>.
+    </para>
+
+    <note>
+      <para>
+        The following parameters in the configuration file can be overridden with
+        command line options:
+        <itemizedlist>
+          <listitem>
+            <simpara>
+              <literal>-L/--log-level</literal> overrides <literal>log_level</literal> in
+              <filename>repmgr.conf</filename>
+            </simpara>
+          </listitem>
+          <listitem>
+            <simpara>
+              <literal>-b/--pg_bindir</literal> overrides <literal>pg_bindir</literal> in
+              <filename>repmgr.conf</filename>
+            </simpara>
+          </listitem>
+        </itemizedlist>
+      </para>
+    </note>
+
+  </sect2>
 
   <sect2 id="configuration-file-location" xreflabel="configuration file location">
   <title>Configuration file location</title>

doc/configuration.xml

@@ -305,6 +305,7 @@
 
   &configuration-file;
   &configuration-file-required-settings;
+  &configuration-file-optional-settings;
   &configuration-file-log-settings;
   &configuration-file-service-commands;
 

doc/filelist.xml

@@ -18,6 +18,7 @@
 <!ENTITY configuration      SYSTEM "configuration.xml">
 <!ENTITY configuration-file      SYSTEM "configuration-file.xml">
 <!ENTITY configuration-file-required-settings      SYSTEM "configuration-file-required-settings.xml">
+<!ENTITY configuration-file-optional-settings      SYSTEM "configuration-file-optional-settings.xml">
 <!ENTITY configuration-file-log-settings      SYSTEM "configuration-file-log-settings.xml">
 <!ENTITY configuration-file-service-commands   SYSTEM "configuration-file-service-commands.xml">
 <!ENTITY cloning-standbys  SYSTEM "cloning-standbys.xml">

doc/install-requirements.xml

@@ -14,7 +14,7 @@
   </para>
 
   <para>
-   &repmgr; 4.x is compatible with all PostgreSQL versions from 9.3. See
+   &repmgr; &repmgrversion; is compatible with all PostgreSQL versions from 9.3. See
    section <link linkend="install-compatibility-matrix">&repmgr; compatibility matrix</link>
    for an overview of version compatibility.
   </para>
@@ -39,13 +39,13 @@
 
   <note>
    <simpara>
-     The same &quot;major&quot; &repmgr; version (e.g. <literal>4.2.x</literal>) <emphasis>must</emphasis>
+     The same &quot;major&quot; &repmgr; version (e.g. <literal>&repmgrversion;.x</literal>) <emphasis>must</emphasis>
      be installed on all node in the replication cluster. We strongly recommend keeping all
      nodes on the same (preferably latest) &quot;minor&quot; &repmgr; version to minimize the risk
      of incompatibilities.
    </simpara>
    <simpara>
-     If different &quot;major&quot; &repmgr; versions (e.g. 3.3.x and 4.1.x)
+     If different &quot;major&quot; &repmgr; versions (e.g. 4.1.x and &repmgrversion;.x)
      are installed on different nodes, in the best case &repmgr; (in particular &repmgrd;)
      will not run. In the worst case, you will end up with a broken cluster.
    </simpara>
@@ -114,7 +114,7 @@
               &repmgr; 4.x
             </entry>
             <entry>
-              <link linkend="release-4.2">4.2</link> (2018-10-24)
+              <link linkend="release-current">&repmgrversion;</link> (&releasedate;)
             </entry>
             <entry>
               9.3, 9.4, 9.5, 9.6, 10, 11
@@ -158,7 +158,7 @@
 
 
     <para>
-      Note that some &repmgr; functionality is not available in PostgreSQL 9.3 and PostgreSQL 9.4.
+      Note that some &repmgr; functionality is not available in PostgreSQL 9.3 and PostgreSQL 9.4:
     </para>
     <itemizedlist spacing="compact" mark="bullet">
 

doc/repmgr-cluster-show.xml

@@ -55,7 +55,7 @@
     $ repmgr -f /etc/repmgr.conf cluster show
 
      ID | Name  | Role    | Status    | Upstream | Location | Priority | Timeline | Connection string
-    ----+-------+---------+-----------+----------+----------+----------+-----------------------------------------
+    ----+-------+---------+-----------+----------+----------+----------+----------+-----------------------------------------
      1  | node1 | primary | * running |          | default  | 100      | 1        | host=db_node1 dbname=repmgr user=repmgr
      2  | node2 | standby |   running | node1    | default  | 100      | 1        | host=db_node2 dbname=repmgr user=repmgr
      3  | node3 | standby |   running | node1    | default  | 100      | 1        | host=db_node3 dbname=repmgr user=repmgr</programlisting>
@@ -82,12 +82,12 @@
 	  (but <literal>node3</literal> is not attached to it, and its metadata has not yet been updated);
 	  <literal>node4</literal> is running but rejecting connections (from <literal>node3</literal> at least).
       <programlisting>
-	 ID | Name  | Role    | Status               | Upstream | Location | Priority | Connection string
-	----+-------+---------+----------------------+----------+----------+----------+-----------------------------------------
-	 1  | node1 | primary | ? unreachable        |          | default  | 100      | host=db_node1 dbname=repmgr user=repmgr
-	 2  | node2 | standby | ! running as primary | node1    | default  | 100      | host=db_node2 dbname=repmgr user=repmgr
-	 3  | node3 | standby |   running            | node1    | default  | 100      | host=db_node3 dbname=repmgr user=repmgr
-	 4  | node4 | standby | ? running            | node1    | default  | 100      | host=db_node4 dbname=repmgr user=repmgr
+     ID | Name  | Role    | Status               | Upstream | Location | Priority | Timeline | Connection string
+    ----+-------+---------+----------------------+----------+----------+----------+----------+-----------------------------------------
+     1  | node1 | primary | ? unreachable        |          | default  | 100      | 1        | host=db_node1 dbname=repmgr user=repmgr
+     2  | node2 | standby | ! running as primary | node1    | default  | 100      | 2        | host=db_node2 dbname=repmgr user=repmgr
+     3  | node3 | standby |   running            | node1    | default  | 100      | 1        | host=db_node3 dbname=repmgr user=repmgr
+     4  | node4 | standby | ? running            | node1    | default  | 100      | ?        | host=db_node4 dbname=repmgr user=repmgr
 
     WARNING: following issues were detected
       - unable to connect to node "node1" (ID: 1)

doc/repmgr-standby-clone.xml

@@ -202,6 +202,18 @@
      ensure the <filename>repmgr.conf</filename>
      file is created for the node, and that it has been registered using
      <command><link linkend="repmgr-standby-register">repmgr standby register</link></command>.
+   </para>
+   <tip>
+     <para>
+       To register a standby which is not running, execute
+       <link linkend="repmgr-standby-register">repmgr standby register --force</link>
+       and provide the connection details for the primary.
+     </para>
+     <para>
+       See <xref linkend="repmgr-standby-register-inactive-node"/> for more details.
+     </para>
+   </tip>
+   <para>
      Then execute the command <command>repmgr standby clone --recovery-conf-only</command>.
      This will create the <filename>recovery.conf</filename> file needed to attach
      the node to its upstream, and will also create a replication slot on the
@@ -326,9 +338,13 @@
         <term><option>--upstream-conninfo</option></term>
         <listitem>
           <para>
-            <literal>primary_conninfo</literal> value to write in recovery.conf
+            <literal>primary_conninfo</literal> value to write in <filename>recovery.conf</filename>
             when the intended upstream server does not yet exist.
           </para>
+          <para>
+            Note that &repmgr; may modify the provided value, in particular to set the
+            correct <literal>application_name</literal>.
+          </para>
         </listitem>
       </varlistentry>
 

doc/repmgr-standby-follow.xml

@@ -20,22 +20,17 @@
       ("follow target"). Typically this will be the primary, but this
       command can also be used to attach the standby to another standby.
     </para>
+
     <para>
-      This command requires a valid
-      <filename>repmgr.conf</filename> file for the standby, either specified
-      explicitly with <literal>-f/--config-file</literal> or located in a
+      This command requires a valid <filename>repmgr.conf</filename> file for the standby,
+      either specified explicitly with <literal>-f/--config-file</literal> or located in a
       default location; no additional arguments are required.
     </para>
 
-	<para>
-	  By default &repmgr; will attempt to attach the standby to the current primary.
-	  If <option>--upstream-node-id</option> is provided, &repmgr; will attempt
-	  to attach the standby to the specified node, which can be another standby.
-	</para>
-
-    <para>
-      This command will force a restart of the standby server, which must be
-      running.
+    <para>The standby node (&quot;follow candidate&quot;) <emphasis>must</emphasis>
+      be running. If the new upstream (&quot;follow target&quot;) is not the primary,
+      the cluster primary <emphasis>must</emphasis> be running and accessible from the
+      standby node.
     </para>
 
     <tip>
@@ -45,6 +40,16 @@
       </para>
     </tip>
 
+    <para>
+      By default &repmgr; will attempt to attach the standby to the current primary.
+      If <option>--upstream-node-id</option> is provided, &repmgr; will attempt
+      to attach the standby to the specified node, which can be another standby.
+    </para>
+
+    <para>
+      This command will force a restart of PostgreSQL on the standby node.
+    </para>
+
     <para>
       <command>repmgr standby follow</command> will wait up to
       <varname>standby_follow_timeout</varname> seconds (default: <literal>30</literal>)
@@ -166,7 +171,7 @@
       be possible to follow the new upstream node, and &repmgr; will emit an error
       message like this:
       <programlisting>
-ERROR: this node cannot attach to follow target node 3
+ERROR: this node cannot attach to follow target node &quot;node3&quot; (ID 3)
 DETAIL: follow target server's timeline 2 forked off current database system timeline 1 before current recovery point 0/6108880</programlisting>
     </para>
     <para>

doc/repmgr-standby-register.xml

@@ -75,10 +75,22 @@
    <para>
     Under some circumstances you may wish to register a standby which is not
     yet running; this can be the case when using provisioning tools to create
-    a complex replication cluster. In this case, by using the <option>-F/--force</option>
-    option and providing the connection parameters to the primary server,
-    the standby can be registered.
+    a complex replication cluster, or if the node was not cloned by &repmgr;.
    </para>
+   <para>
+    In this case, by using the <option>-F/--force</option>
+    option and providing the connection parameters to the primary server,
+    the standby can be registered even if it has not yet been started.
+   </para>
+   <tip>
+     <para>
+       Connection parameters can either be provided either as a <literal>conninfo</literal> string
+       (e.g. <option>-d 'host=node1 user=repmgr'</option> or as individual connection parameters
+        (<option>-h/--host</option>, <option>-d/--dbname</option>,
+       <option>-U/--user</option>, <option>-p/--port</option> etc.).
+     </para>
+   </tip>
+
    <para>
     Similarly, with cascading replication it may be necessary to register
     a standby whose upstream node has not yet been registered - in this case,
@@ -96,9 +108,10 @@
     <title>Registering a node not cloned by repmgr</title>
     <para>
       If you've cloned a standby using another method (e.g. <application>barman</application>'s
-     <command>barman recover</command> command), first execute
+     <command>barman recover</command> command), register the node as detailed in section
+     <xref linkend="repmgr-standby-register-inactive-node"/> then execute
      <link linkend="repmgr-standby-create-recovery-conf">repmgr standby clone --recovery-conf-only</link>
-     to add the <filename>recovery.conf</filename> file, then register the standby as usual.
+     to generate the appropriate replication configuration.
     </para>
   </refsect1>
 
@@ -119,7 +132,7 @@
 
 
       <varlistentry>
-       <term><option>-F</option><option>--force</option></term>
+       <term><option>-F</option>/<option>--force</option></term>
         <listitem>
           <para>
             Overwrite an existing node record

doc/repmgrd-automatic-failover.xml

@@ -55,7 +55,7 @@
    </para>
  </note>
  <para>
-   For more complex replication scenarios,e.g. with multiple datacentres, it may
+   For more complex replication scenarios, e.g. with multiple datacentres, it may
    be preferable to use location-based failover, which ensures that only nodes
    in the same location as the primary will ever be promotion candidates;
    see <xref linkend="repmgrd-network-split"/> for more details.

doc/repmgrd-configuration.xml

@@ -15,9 +15,13 @@
   </para>
   <para>
     &repmgrd; can be configured to provide failover
-    capability in case the primary upstream node becomes unreachable, and/or
+    capability in case the primary or upstream node becomes unreachable, and/or
     provide monitoring data to the &repmgr; metadatabase.
   </para>
+  <para>
+    From &repmgr; 4.4, when running on the primary node, &repmgrd; can also monitor
+    standby disconnections/reconnections (see <xref linkend="repmgrd-primary-child-disconnection"/>).
+  </para>
 
   <sect1 id="repmgrd-basic-configuration">
     <title>repmgrd configuration</title>
@@ -222,6 +226,17 @@
               Normally <option>promote_command</option> is set as &repmgr;'s
               <command><link linkend="repmgr-standby-promote">repmgr standby promote</link></command> command.
             </para>
+
+            <note>
+              <para>
+                When invoking <command>repmgr standby promote</command> (either directly via
+                the <option>promote_command</option>, or in a script called
+                via <option>promote_command</option>), <option>--siblings-follow</option>
+                <emphasis>must not</emphasis> be included as a
+                command line option for <command>repmgr standby promote</command>.
+              </para>
+            </note>
+
             <para>
               It is also possible to provide a shell script to e.g. perform user-defined tasks
               before promoting the current node. In this case the script <emphasis>must</emphasis>
@@ -554,7 +569,8 @@ repmgrd_service_stop_command='sudo systemctl repmgr11 stop'
         the option <option>monitor_interval_secs</option> (see above).
       </para>
       <para>
-        For more details on monitoring, see <xref linkend="repmgrd-monitoring"/>.
+        For more details on monitoring, see <xref linkend="repmgrd-monitoring"/>. For information on
+        monitoring standby disconnections, see <xref linkend="repmgrd-primary-child-disconnection"/>.
       </para>
     </sect2>
 

doc/switchover.xml

@@ -317,7 +317,7 @@
   </para>
   <para>
     If &repmgrd; is in use, it's worth double-checking that
-    all nodes are unpaused by executing <command><link linkend="repmgr-daemon-status">repmgr-daemon-status</link></command>.
+    all nodes are unpaused by executing <command><link linkend="repmgr-daemon-status">repmgr daemon status</link></command>.
   </para>
 
    <note>

doc/upgrading-repmgr.xml

@@ -263,7 +263,7 @@ ALTER EXTENSION repmgr UPDATE</programlisting>
   <tip>
 	<para>
 	  Use <command><link linkend="repmgr-node-check">repmgr node check</link></command>
-	  to determine which replacation slots need to be recreated.
+	  to determine which replication slots need to be recreated.
 	</para>
   </tip>
 

repmgr--4.0.sql

@@ -78,8 +78,6 @@ CREATE VIEW repmgr.show_nodes AS
 LEFT JOIN repmgr.nodes un
        ON un.node_id = n.upstream_node_id;
 
-
-/* XXX update upgrade scripts! */
 CREATE TABLE repmgr.voting_term (
   term INT NOT NULL
 );

repmgr--4.1.sql

@@ -78,8 +78,6 @@ CREATE VIEW repmgr.show_nodes AS
 LEFT JOIN repmgr.nodes un
        ON un.node_id = n.upstream_node_id;
 
-
-/* XXX update upgrade scripts! */
 CREATE TABLE repmgr.voting_term (
   term INT NOT NULL
 );

repmgr--4.2.sql

@@ -78,8 +78,6 @@ CREATE VIEW repmgr.show_nodes AS
 LEFT JOIN repmgr.nodes un
        ON un.node_id = n.upstream_node_id;
 
-
-/* XXX update upgrade scripts! */
 CREATE TABLE repmgr.voting_term (
   term INT NOT NULL
 );

repmgr--4.3.sql

@@ -78,8 +78,6 @@ CREATE VIEW repmgr.show_nodes AS
 LEFT JOIN repmgr.nodes un
        ON un.node_id = n.upstream_node_id;
 
-
-/* XXX update upgrade scripts! */
 CREATE TABLE repmgr.voting_term (
   term INT NOT NULL
 );

repmgr--4.4.sql

@@ -78,8 +78,6 @@ CREATE VIEW repmgr.show_nodes AS
 LEFT JOIN repmgr.nodes un
        ON un.node_id = n.upstream_node_id;
 
-
-/* XXX update upgrade scripts! */
 CREATE TABLE repmgr.voting_term (
   term INT NOT NULL
 );

repmgr-action-node.c

@@ -1833,7 +1833,7 @@ do_node_check_data_directory(PGconn *conn, OutputMode mode, t_node_info *node_in
 	 * a superuser connection
 	 */
 
-	if (is_superuser_connection(conn, NULL) == true)
+	if (connection_has_pg_settings(conn) == true)
 	{
 		/* we expect to have a database connection */
 		if (get_pg_setting(conn, "data_directory", actual_data_directory) == false)
@@ -1878,7 +1878,7 @@ do_node_check_data_directory(PGconn *conn, OutputMode mode, t_node_info *node_in
 			/* XXX add -S/--superuser option */
 			if (PQserverVersion(conn) >= 100000)
 			{
-				log_hint(_("add the \"%s\" user to group \"pg_read_all_settings\""),
+				log_hint(_("add the \"%s\" user to group \"pg_read_all_settings\" or \"pg_monitor\""),
 						   PQuser(conn));
 			}
 		}

repmgr-action-standby.c

@@ -112,7 +112,7 @@ static void get_barman_property(char *dst, char *name, char *local_repmgr_direct
 static int	get_tablespace_data_barman(char *, TablespaceDataList *);
 static char *make_barman_ssh_command(char *buf);
 
-static bool create_recovery_file(t_node_info *node_record, t_conninfo_param_list *recovery_conninfo, char *dest, bool as_file);
+static bool create_recovery_file(t_node_info *node_record, t_conninfo_param_list *primary_conninfo, char *dest, bool as_file);
 static void write_primary_conninfo(PQExpBufferData *dest, t_conninfo_param_list *param_list);
 static bool check_sibling_nodes(NodeInfoList *sibling_nodes, SiblingNodeStats *sibling_nodes_stats);
 static bool check_free_wal_senders(int available_wal_senders, SiblingNodeStats *sibling_nodes_stats, bool *dry_run_success);
@@ -1000,6 +1000,9 @@ _do_create_recovery_conf(void)
 	/* check connection */
 	source_conn = establish_db_connection_by_params(&source_conninfo, true);
 
+	/* Verify that source is a supported server version */
+	(void) check_server_version(source_conn, "source node", true, NULL);
+
 	/* determine node for primary_conninfo */
 
 	if (runtime_options.upstream_node_id != UNKNOWN_NODE_ID)
@@ -2784,12 +2787,6 @@ do_standby_follow(void)
 
 	PQfinish(local_conn);
 
-	if (runtime_options.dry_run == true)
-	{
-		log_info(_("prerequisites for executing STANDBY FOLLOW are met"));
-		exit(SUCCESS);
-	}
-
 	/*
 	 * Here we'll need a connection to the primary, if the upstream is not a primary.
 	 */
@@ -2802,12 +2799,30 @@ do_standby_follow(void)
 		primary_conn = get_primary_connection_quiet(follow_target_conn,
 													&primary_node_id,
 													NULL);
+
+		/*
+		 * If follow target is not primary and no other primary could be found,
+		 * abort because we won't be able to update the node record.
+		 */
+		if (PQstatus(primary_conn) != CONNECTION_OK)
+		{
+			log_error(_("unable to determine the cluster primary"));
+			log_detail(_("an active primary node is required for \"repmgr standby follow\""));
+			PQfinish(follow_target_conn);
+			exit(ERR_FOLLOW_FAIL);
+		}
 	}
 	else
 	{
 		primary_conn = follow_target_conn;
 	}
 
+	if (runtime_options.dry_run == true)
+	{
+		log_info(_("prerequisites for executing STANDBY FOLLOW are met"));
+		exit(SUCCESS);
+	}
+
 	initPQExpBuffer(&follow_output);
 
 	success = do_standby_follow_internal(
@@ -2991,42 +3006,9 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 		}
 	}
 
-	/* Initialise connection parameters to write as `primary_conninfo` */
-	initialize_conninfo_params(&recovery_conninfo, false);
-
-	/* We ignore any application_name set in the primary's conninfo */
-	parse_conninfo_string(follow_target_node_record->conninfo, &recovery_conninfo, &errmsg, true);
-
-	{
-		t_conninfo_param_list local_node_conninfo = T_CONNINFO_PARAM_LIST_INITIALIZER;
-		bool		parse_success;
-
-		initialize_conninfo_params(&local_node_conninfo, false);
-
-		parse_success = parse_conninfo_string(local_node_record.conninfo, &local_node_conninfo, &errmsg, false);
-
-		if (parse_success == false)
-		{
 	/*
-			 * this shouldn't happen, but if it does we'll plough on
-			 * regardless
-			 */
-			log_warning(_("unable to parse conninfo string \"%s\":\n  %s"),
-						local_node_record.conninfo, errmsg);
-		}
-		else
-		{
-			char	   *application_name = param_get(&local_node_conninfo, "application_name");
-
-			if (application_name != NULL && strlen(application_name))
-				param_set(&recovery_conninfo, "application_name", application_name);
-		}
-
-		free_conninfo_params(&local_node_conninfo);
-
-		/*
-		 * store the original upstream node id so we can delete the
-		 * replication slot, if exists
+	 * Store the original upstream node id so we can delete the
+	 * replication slot, if it exists.
 	 */
 	if (local_node_record.upstream_node_id != UNKNOWN_NODE_ID)
 	{
@@ -3037,8 +3019,14 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 		original_upstream_node_id = follow_target_node_record->node_id;
 	}
 
-
-		if (config_file_options.use_replication_slots && runtime_options.host_param_provided == false && original_upstream_node_id != UNKNOWN_NODE_ID)
+	if (config_file_options.use_replication_slots && runtime_options.host_param_provided == false)
+	{
+		/*
+		 * Only attempt to delete the old replication slot if the old upstream
+		 * node is known and is different to the follow target node.
+		 */
+		if (original_upstream_node_id != UNKNOWN_NODE_ID
+		 && original_upstream_node_id != follow_target_node_record->node_id)
 		{
 			remove_old_replication_slot = true;
 		}
@@ -3066,6 +3054,12 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 		}
 	}
 
+	/* Initialise connection parameters to write as "primary_conninfo" */
+	initialize_conninfo_params(&recovery_conninfo, false);
+
+	/* We ignore any application_name set in the primary's conninfo */
+	parse_conninfo_string(follow_target_node_record->conninfo, &recovery_conninfo, &errmsg, true);
+
 	/* Set the application name to this node's name */
 	param_set(&recovery_conninfo, "application_name", config_file_options.node_name);
 
@@ -3187,8 +3181,6 @@ do_standby_follow_internal(PGconn *primary_conn, PGconn *follow_target_conn, t_n
 	 * Note that if this function is called by do_standby_switchover(), the
 	 * "repmgr node rejoin" command executed on the demotion candidate may already
 	 * have removed the slot, so there may be nothing to do.
-	 *
-	 * XXX check if former upstream is current primary?
 	 */
 
 	if (remove_old_replication_slot == true)
@@ -4769,6 +4761,7 @@ check_source_server()
 	t_node_info upstream_node_record = T_NODE_INFO_INITIALIZER;
 	RecordStatus record_status = RECORD_NOT_FOUND;
 	ExtensionStatus extension_status = REPMGR_UNKNOWN;
+	t_extension_versions extversions = T_EXTENSION_VERSIONS_INITIALIZER;
 
 	/* Attempt to connect to the upstream server to verify its configuration */
 	log_verbose(LOG_DEBUG, "check_source_server()");
@@ -4832,7 +4825,7 @@ check_source_server()
 	 * to be used as a standalone clone tool)
 	 */
 
-	extension_status = get_repmgr_extension_status(primary_conn, NULL);
+	extension_status = get_repmgr_extension_status(primary_conn, &extversions);
 
 	if (extension_status != REPMGR_INSTALLED)
 	{
@@ -4847,20 +4840,25 @@ check_source_server()
 				exit(ERR_DB_QUERY);
 			}
 
-			/* schema doesn't exist */
-			log_error(_("repmgr extension not found on source node"));
-
 			if (extension_status == REPMGR_AVAILABLE)
 			{
-				log_detail(_("repmgr extension is available but not installed in database \"%s\""),
+				log_error(_("repmgr extension is available but not installed in database \"%s\""),
 						   param_get(&source_conninfo, "dbname"));
+				log_hint(_("check that you are cloning from the database where \"repmgr\" is installed"));
 			}
 			else if (extension_status == REPMGR_UNAVAILABLE)
 			{
-				log_detail(_("repmgr extension is not available on the upstream node"));
+				log_error(_("repmgr extension is not available on the upstream node"));
+			}
+			else if (extension_status == REPMGR_OLD_VERSION_INSTALLED)
+			{
+				log_error(_("an older version of the extension is installed on the upstream node"));
+				log_detail(_("version %s is installed but newer version %s is available"),
+						   extversions.installed_version,
+						   extversions.default_version);
+				log_hint(_("upgrade \"repmgr\" on the source node first"));
 			}
 
-			log_hint(_("check that the upstream node is part of a repmgr cluster"));
 			PQfinish(source_conn);
 			exit(ERR_BAD_CONFIG);
 		}
@@ -4885,6 +4883,13 @@ check_source_server()
 		 * later, as this is a precautionary check and we can retrieve the system
 		 * identifier with a normal connection.
 		 */
+
+		if (runtime_options.dry_run == true)
+		{
+			log_info(_("\"repmgr\" extension is installed in database \"%s\""),
+					 param_get(&source_conninfo, "dbname"));
+		}
+
 		if (get_recovery_type(source_conn) == RECTYPE_PRIMARY && PQserverVersion(source_conn) >= 90600)
 		{
 			uint64		source_system_identifier = system_identifier(source_conn);
@@ -6942,11 +6947,11 @@ check_recovery_type(PGconn *conn)
  * Creates a recovery.conf file for a standby
  *
  * A database connection pointer is required for escaping primary_conninfo
- * parameters. When cloning from Barman and --no-upstream-connection ) this
- * might not be available.
+ * parameters. When cloning from Barman and --no-upstream-connection supplied,
+ * this might not be available.
  */
-bool
-create_recovery_file(t_node_info *node_record, t_conninfo_param_list *recovery_conninfo, char *dest, bool as_file)
+static bool
+create_recovery_file(t_node_info *node_record, t_conninfo_param_list *primary_conninfo, char *dest, bool as_file)
 {
 	PQExpBufferData recovery_file_buf;
 	char		recovery_file_path[MAXPGPATH] = "";
@@ -6961,29 +6966,7 @@ create_recovery_file(t_node_info *node_record, t_conninfo_param_list *recovery_c
 						 "standby_mode = 'on'\n");
 
 	/* primary_conninfo = '...' */
-
-	/*
-	 * the user specified --upstream-conninfo string - copy that
-	 */
-	if (strlen(runtime_options.upstream_conninfo))
-	{
-		char	   *escaped = escape_recovery_conf_value(runtime_options.upstream_conninfo);
-
-		appendPQExpBuffer(&recovery_file_buf,
-						  "primary_conninfo = '%s'\n",
-						  escaped);
-
-		free(escaped);
-	}
-
-	/*
-	 * otherwise use the conninfo inferred from the upstream connection and/or
-	 * node record
-	 */
-	else
-	{
-		write_primary_conninfo(&recovery_file_buf, recovery_conninfo);
-	}
+	write_primary_conninfo(&recovery_file_buf, primary_conninfo);
 
 	/* recovery_target_timeline = 'latest' */
 	appendPQExpBufferStr(&recovery_file_buf,

repmgr-client.c

@@ -1908,6 +1908,7 @@ check_cli_parameters(const int action)
 			case NODE_SERVICE:
 			case DAEMON_PAUSE:
 			case DAEMON_UNPAUSE:
+			case DAEMON_STATUS:
 			case DAEMON_START:
 			case DAEMON_STOP:
 				break;
@@ -2833,15 +2834,25 @@ create_repmgr_extension(PGconn *conn)
 int
 check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *server_version_string)
 {
-	int			conn_server_version_num = get_server_version(conn, server_version_string);
+	char		version_string[MAXVERSIONSTR] = "";
+	int			conn_server_version_num = get_server_version(conn, version_string);
+
+	/* Copy the version string, if the caller wants it */
+	if (server_version_string != NULL)
+		strncpy(server_version_string, version_string, MAXVERSIONSTR);
 
 	if (conn_server_version_num < MIN_SUPPORTED_VERSION_NUM)
 	{
 		if (conn_server_version_num > 0)
+		{
 			log_error(_("%s requires %s to be PostgreSQL %s or later"),
 					  progname(),
 					  server_type,
 					  MIN_SUPPORTED_VERSION);
+			log_detail(_("%s server version is %s"),
+					   server_type,
+					   version_string);
+		}
 
 		if (exit_on_error == true)
 		{
@@ -2852,6 +2863,38 @@ check_server_version(PGconn *conn, char *server_type, bool exit_on_error, char *
 		return UNKNOWN_SERVER_VERSION_NUM;
 	}
 
+	/*
+	 * If it's clear a particular repmgr feature branch won't be able to support
+	 * PostgreSQL from a particular PostgreSQL release onwards (e.g. 4.4 with PostgreSQL
+	 * 12 and later due to recovery.conf removal), set MAX_UNSUPPORTED_VERSION and
+	 * MAX_UNSUPPORTED_VERSION_NUM in "repmgr.h" to define the first PostgreSQL
+	 * version which can't be suppored.
+	 */
+#ifdef MAX_UNSUPPORTED_VERSION_NUM
+	if (conn_server_version_num >= MAX_UNSUPPORTED_VERSION_NUM)
+	{
+		if (conn_server_version_num > 0)
+		{
+			log_error(_("%s %s does not support PostgreSQL %s or later"),
+					  progname(),
+					  REPMGR_VERSION,
+					  MAX_UNSUPPORTED_VERSION);
+			log_detail(_("%s server version is %s"),
+					   server_type,
+					   version_string);
+			log_hint(_("For details of supported versions see: https://repmgr.org/docs/current/install-requirements.html#INSTALL-COMPATIBILITY-MATRIX"));
+		}
+
+		if (exit_on_error == true)
+		{
+			PQfinish(conn);
+			exit(ERR_BAD_CONFIG);
+		}
+
+		return UNKNOWN_SERVER_VERSION_NUM;
+	}
+#endif
+
 	return conn_server_version_num;
 }
 
@@ -3029,18 +3072,18 @@ copy_remote_files(char *host, char *remote_user, char *remote_path,
 
 	if (*config_file_options.rsync_options == '\0')
 	{
-		appendPQExpBuffer(&rsync_flags, "%s",
+		appendPQExpBufferStr(&rsync_flags,
 							 "--archive --checksum --compress --progress --rsh=ssh");
 	}
 	else
 	{
-		appendPQExpBuffer(&rsync_flags, "%s",
+		appendPQExpBufferStr(&rsync_flags,
 							 config_file_options.rsync_options);
 	}
 
 	if (runtime_options.force)
 	{
-		appendPQExpBuffer(&rsync_flags, "%s",
+		appendPQExpBufferStr(&rsync_flags,
 							 " --delete --checksum");
 	}
 
@@ -3067,10 +3110,10 @@ copy_remote_files(char *host, char *remote_user, char *remote_path,
 	if (is_directory)
 	{
 		/* Files which we don't want */
-		appendPQExpBuffer(&rsync_flags, "%s",
+		appendPQExpBufferStr(&rsync_flags,
 							 " --exclude=postmaster.pid --exclude=postmaster.opts --exclude=global/pg_control");
 
-		appendPQExpBuffer(&rsync_flags, "%s",
+		appendPQExpBufferStr(&rsync_flags,
 							 " --exclude=recovery.conf --exclude=recovery.done");
 
 		if (server_version_num >= 90400)
@@ -3079,7 +3122,7 @@ copy_remote_files(char *host, char *remote_user, char *remote_path,
 			 * Ideally we'd use PG_AUTOCONF_FILENAME from utils/guc.h, but
 			 * that has too many dependencies for a mere client program.
 			 */
-			appendPQExpBuffer(&rsync_flags, "%s",
+			appendPQExpBufferStr(&rsync_flags,
 								 " --exclude=postgresql.auto.conf.tmp");
 		}
 
@@ -3091,16 +3134,16 @@ copy_remote_files(char *host, char *remote_user, char *remote_path,
 
 		if (server_version_num >= 100000)
 		{
-			appendPQExpBuffer(&rsync_flags, "%s",
+			appendPQExpBufferStr(&rsync_flags,
 								 " --exclude=pg_wal/*");
 		}
 		else
 		{
-			appendPQExpBuffer(&rsync_flags, "%s",
+			appendPQExpBufferStr(&rsync_flags,
 								 " --exclude=pg_xlog/*");
 		}
 
-		appendPQExpBuffer(&rsync_flags, "%s",
+		appendPQExpBufferStr(&rsync_flags,
 							 " --exclude=pg_log/* --exclude=pg_stat_tmp/*");
 
 		maxlen_snprintf(script, "rsync %s %s:%s/* %s",

repmgr.c

@@ -702,7 +702,7 @@ set_repmgrd_pid(PG_FUNCTION_ARGS)
 	shared_state->repmgrd_pid = repmgrd_pid;
 	memset(shared_state->repmgrd_pidfile, 0, MAXPGPATH);
 
-	if(repmgrd_pidfile != NULL)
+	if (repmgrd_pidfile != NULL)
 	{
 		strncpy(shared_state->repmgrd_pidfile, repmgrd_pidfile, MAXPGPATH);
 	}

repmgr.conf.sample

@@ -51,7 +51,6 @@
 
 
 # =============================================================================
-
 # Optional configuration items
 # =============================================================================
 
@@ -68,16 +67,16 @@
 # Replication settings
 #------------------------------------------------------------------------------
 
-#replication_user='repmgr'	 # User to make replication connections with, if not set defaults
-				 # to the user defined in "conninfo".
+#replication_user='repmgr'	 # User to make replication connections with, if not set
+				 #  defaults to the user defined in "conninfo".
 
-#replication_type=physical	 # Must be one of 'physical' or 'bdr'.
+#replication_type=physical	 # Must be one of "physical" or "bdr".
 				 # NOTE: "bdr" can only be used with BDR 2.x
 
-#location=default		 # arbitrary string defining the location of the node; this
-				 # is used during failover to check visibilty of the
-				 # current primary node. See the 'repmgrd' documentation
-				 # in README.md for further details.
+#location=default		 # An arbitrary string defining the location of the node; this
+				 # is used during failover to check visibility of the
+				 # current primary node. For further details see:
+                                 #   https://repmgr.org/docs/current/repmgrd-network-split.html
 
 #use_replication_slots=no	 # whether to use physical replication slots
 				 # NOTE: when using replication slots,

repmgr.h

@@ -21,6 +21,37 @@
 #include <config.h>
 #endif
 
+#ifdef vsnprintf
+#undef vsnprintf
+#endif
+#ifdef snprintf
+#undef snprintf
+#endif
+#ifdef vsprintf
+#undef vsprintf
+#endif
+#ifdef sprintf
+#undef sprintf
+#endif
+#ifdef vfprintf
+#undef vfprintf
+#endif
+#ifdef fprintf
+#undef fprintf
+#endif
+#ifdef vprintf
+#undef vprintf
+#endif
+#ifdef printf
+#undef printf
+#endif
+#ifdef strerror
+#undef strerror
+#endif
+#ifdef strerror_r
+#undef strerror_r
+#endif
+
 #ifndef _REPMGR_H_
 #define _REPMGR_H_
 
@@ -46,6 +77,9 @@
 #define MIN_SUPPORTED_VERSION		"9.3"
 #define MIN_SUPPORTED_VERSION_NUM	90300
 
+#define MAX_UNSUPPORTED_VERSION		"12"
+#define MAX_UNSUPPORTED_VERSION_NUM	120000
+
 #define REPLICATION_TYPE_PHYSICAL 1
 #define REPLICATION_TYPE_BDR	  2
 

repmgr_version.h.in

@@ -1,3 +1,4 @@
 #define REPMGR_VERSION_DATE ""
-#define REPMGR_VERSION "4.4dev"
+#define REPMGR_VERSION "4.4"
 #define REPMGR_VERSION_NUM 40400
+#define REPMGR_RELEASE_DATE "2019-06-27"

repmgrd-physical.c

@@ -4909,7 +4909,8 @@ check_node_can_follow(PGconn *local_conn, XLogRecPtr local_xlogpos, PGconn *foll
 		 */
 		if (local_xlogpos > follow_target_history->end)
 		{
-			log_error(_("this node cannot attach to follow target node %i"),
+			log_error(_("this node cannot attach to follow target node \"%s\" (ID: %i)"),
+					  follow_target_node_info->node_name,
 					  follow_target_node_info->node_id);
 			can_follow = false;
 
@@ -4921,8 +4922,10 @@ check_node_can_follow(PGconn *local_conn, XLogRecPtr local_xlogpos, PGconn *foll
 
 		if (can_follow == true)
 		{
-			log_info(_("local node %i can attach to follow target node %i"),
+			log_info(_("local node \"%s\" (ID: %i) can attach to follow target node \"%s\" (ID: %i)"),
+					 config_file_options.node_name,
 					 config_file_options.node_id,
+					 follow_target_node_info->node_name,
 					 follow_target_node_info->node_id);
 
 			log_detail(_("local node's recovery point: %X/%X; follow target node's fork point: %X/%X"),