Fix pre-9.6 wal_level check

archive_command set in postgresql.conf

Fixes #154

HISTORY

@@ -1,4 +1,13 @@
-3.1.1   2016-02-
+3.1.2   2016-04-12
+        Fix pg_ctl path generation in do_standby_switchover() (Ian)
+        Regularly sync witness server repl_nodes table (Ian)
+        Documentation improvements (Gianni, dhyannataraj)
+        (Experimental) ensure repmgr handles failover slots when copying
+          in rsync mode (Craig, Ian)
+        rsync mode handling fixes (Martín)
+        Enable repmgr to compile against 9.6devel (Ian)
+
+3.1.1   2016-02-24
         Add '-P/--pwprompt' option for "repmgr create witness" (Ian)
         Prevent repmgr/repmgrd running as root (Ian)
 

Makefile

@@ -2,23 +2,32 @@
 # Makefile
 # Copyright (c) 2ndQuadrant, 2010-2016
 
+HEADERS = $(wildcard *.h)
+
 repmgrd_OBJS = dbutils.o config.o repmgrd.o log.o strutil.o
 repmgr_OBJS = dbutils.o check_dir.o config.o repmgr.o log.o strutil.o
 
 DATA = repmgr.sql uninstall_repmgr.sql
 
 PG_CPPFLAGS = -I$(libpq_srcdir)
-PG_LIBS = $(libpq_pgport)
+PG_LIBS     = $(libpq_pgport)
 
-all:  repmgrd repmgr
+
+all: repmgrd repmgr
 	$(MAKE) -C sql
 
 repmgrd: $(repmgrd_OBJS)
-	$(CC) $(CFLAGS) $(repmgrd_OBJS) $(PG_LIBS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) -o repmgrd
+	$(CC) -o repmgrd $(CFLAGS) $(repmgrd_OBJS) $(PG_LIBS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS)
 	$(MAKE) -C sql
 
 repmgr: $(repmgr_OBJS)
-	$(CC) $(CFLAGS) $(repmgr_OBJS) $(PG_LIBS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) -o repmgr
+	$(CC) -o repmgr $(CFLAGS) $(repmgr_OBJS) $(PG_LIBS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS)
+
+# Make all objects depend on all include files. This is a bit of a
+# shotgun approach, but the codebase is small enough that a complete rebuild
+# is very fast anyway.
+$(repmgr_OBJS): $(HEADERS)
+$(repmgrd_OBJS): $(HEADERS)
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config
@@ -31,8 +40,8 @@ include $(top_builddir)/src/Makefile.global
 include $(top_srcdir)/contrib/contrib-global.mk
 endif
 
-# XXX: Try to use PROGRAM construct (see pgxs.mk) someday. Right now
-# is overriding pgxs install.
+# XXX: This overrides the pgxs install target - we're building two binaries,
+# which is not supported by pgxs.mk's PROGRAM construct.
 install: install_prog install_ext
 
 install_prog:
@@ -43,6 +52,12 @@ install_prog:
 install_ext:
 	$(MAKE) -C sql install
 
+# Distribution-specific package building targets
+# ----------------------------------------------
+#
+# XXX we recommend using the PGDG-supplied packages where possible;
+# see README.md for details.
+
 install_rhel:
 	mkdir -p '$(DESTDIR)/etc/init.d/'
 	$(INSTALL_PROGRAM) RHEL/repmgrd.init '$(DESTDIR)/etc/init.d/repmgrd'

README.md

@@ -259,6 +259,20 @@ The following replication settings must be included in `postgresql.conf`:
 
     hot_standby = on
 
+    # If archive_mode is enabled, check that 'archive_command' is non empty
+    # (however it's not practical to check that it actually represents a valid
+    # command).
+    # 
+    # From PostgreSQL 9.5, archive_mode can be one of 'off', 'on' or 'always'
+    # so for ease of backwards compatibility, rather than explicitly check for an
+    # enabled mode, check that it's not "off".
+    archive_mode = on
+
+    # Set archive command to a script or application that will safetly store
+    # you WALs in a secure place. /bin/true is an example of a command that
+    # ignores archiving. Use something more sensible.
+    archive_command = '/bin/true'
+
 
 * * *
 
@@ -284,11 +298,11 @@ similar to the following:
 
     local   replication   repmgr                              trust
     host    replication   repmgr      127.0.0.1/32            trust
-    host    replication   repmgr      192.168.1.0/32          trust
+    host    replication   repmgr      192.168.1.0/24          trust
 
     local   repmgr        repmgr                              trust
     host    repmgr        repmgr      127.0.0.1/32            trust
-    host    repmgr        repmgr      192.168.1.0/32          trust
+    host    repmgr        repmgr      192.168.1.0/24          trust
 
 Adjust according to your network environment and authentication requirements.
 
@@ -876,6 +890,10 @@ be set in `repmgr.conf`:
 
 (See `repmgr.conf.sample` for further `repmgrd`-specific settings).
 
+Additionally, `postgresql.conf` must contain the following line:
+
+    shared_preload_libraries = 'repmgr_funcs'
+
 When `failover` is set to `automatic`, upon detecting failure of the current
 master, `repmgrd` will execute one of `promote_command` or `follow_command`,
 depending on whether the current server is becoming the new master or

config.c

@@ -235,6 +235,9 @@ parse_config(t_configuration_options *options)
 	options->monitor_interval_secs = 2;
 	options->retry_promote_interval_secs = 300;
 
+	/* default to resyncing repl_nodes table every 30 seconds on the witness server */
+	options->witness_repl_nodes_sync_interval_secs = 30;
+
 	memset(options->event_notification_command, 0, sizeof(options->event_notification_command));
 
 	options->tablespace_mapping.head = NULL;
@@ -358,6 +361,8 @@ parse_config(t_configuration_options *options)
 			options->monitor_interval_secs = repmgr_atoi(value, "monitor_interval_secs", &config_errors, false);
 		else if (strcmp(name, "retry_promote_interval_secs") == 0)
 			options->retry_promote_interval_secs = repmgr_atoi(value, "retry_promote_interval_secs", &config_errors, false);
+		else if (strcmp(name, "witness_repl_nodes_sync_interval_secs") == 0)
+			options->witness_repl_nodes_sync_interval_secs = repmgr_atoi(value, "witness_repl_nodes_sync_interval_secs", &config_errors, false);
 		else if (strcmp(name, "use_replication_slots") == 0)
 			/* XXX we should have a dedicated boolean argument format */
 			options->use_replication_slots = repmgr_atoi(value, "use_replication_slots", &config_errors, false);

config.h

@@ -75,13 +75,14 @@ typedef struct
 	char		logfile[MAXLEN];
 	int			monitor_interval_secs;
 	int			retry_promote_interval_secs;
+	int			witness_repl_nodes_sync_interval_secs;
 	int			use_replication_slots;
 	char		event_notification_command[MAXLEN];
 	EventNotificationList event_notifications;
 	TablespaceList tablespace_mapping;
 }	t_configuration_options;
 
-#define T_CONFIGURATION_OPTIONS_INITIALIZER { "", -1, NO_UPSTREAM_NODE, "", MANUAL_FAILOVER, -1, "", "", "", "", "", "", "", -1, -1, -1, "", "", "", "", 0, 0, 0, "", { NULL, NULL }, {NULL, NULL} }
+#define T_CONFIGURATION_OPTIONS_INITIALIZER { "", -1, NO_UPSTREAM_NODE, "", MANUAL_FAILOVER, -1, "", "", "", "", "", "", "", -1, -1, -1, "", "", "", "", 0, 0, 0, 0, "", { NULL, NULL }, {NULL, NULL} }
 
 typedef struct ErrorListCell
 {

dbutils.c

@@ -889,7 +889,7 @@ get_repmgr_schema_quoted(PGconn *conn)
 
 
 bool
-create_replication_slot(PGconn *conn, char *slot_name)
+create_replication_slot(PGconn *conn, char *slot_name, int server_version_num)
 {
 	char				sqlquery[QUERY_STR_LEN];
 	int					query_res;
@@ -926,9 +926,19 @@ create_replication_slot(PGconn *conn, char *slot_name)
 		return false;
 	}
 
-	sqlquery_snprintf(sqlquery,
-					  "SELECT * FROM pg_create_physical_replication_slot('%s')",
-					  slot_name);
+	/* In 9.6 and later, reserve the LSN straight away */
+	if (server_version_num >= 90600)
+	{
+		sqlquery_snprintf(sqlquery,
+						  "SELECT * FROM pg_create_physical_replication_slot('%s', TRUE)",
+						  slot_name);
+	}
+	else
+	{
+		sqlquery_snprintf(sqlquery,
+						  "SELECT * FROM pg_create_physical_replication_slot('%s')",
+						  slot_name);
+	}
 
 	log_debug(_("create_replication_slot(): Creating slot '%s' on primary\n"), slot_name);
 	log_verbose(LOG_DEBUG, "create_replication_slot():\n%s\n", sqlquery);
@@ -1111,7 +1121,7 @@ set_config_bool(PGconn *conn, const char *config_param, bool state)
 
 
 /*
- * copy_configuration()
+ * witness_copy_node_records()
  *
  * Copy records in master's `repl_nodes` table to witness database
  *
@@ -1119,29 +1129,49 @@ set_config_bool(PGconn *conn, const char *config_param, bool state)
  * `repmgrd` after a failover event occurs
  */
 bool
-copy_configuration(PGconn *masterconn, PGconn *witnessconn, char *cluster_name)
+witness_copy_node_records(PGconn *masterconn, PGconn *witnessconn, char *cluster_name)
 {
 	char		sqlquery[MAXLEN];
 	PGresult   *res;
 	int			i;
 
+	begin_transaction(witnessconn);
+
+	/* Defer constraints */
+	sqlquery_snprintf(sqlquery, "SET CONSTRAINTS ALL DEFERRED;");
+	log_verbose(LOG_DEBUG, "witness_copy_node_records():\n%s\n", sqlquery);
+
+	res = PQexec(witnessconn, sqlquery);
+	if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
+	{
+		log_err(_("Unable to defer constraints:\n%s\n"),
+				PQerrorMessage(witnessconn));
+		rollback_transaction(witnessconn);
+
+		return false;
+	}
+
+	/* Truncate existing records */
 	sqlquery_snprintf(sqlquery, "TRUNCATE TABLE %s.repl_nodes", get_repmgr_schema_quoted(witnessconn));
 
-	log_verbose(LOG_DEBUG, "copy_configuration():\n%s\n", sqlquery);
+	log_verbose(LOG_DEBUG, "witness_copy_node_records():\n%s\n", sqlquery);
 
 	res = PQexec(witnessconn, sqlquery);
 	if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
 	{
 		log_err(_("Unable to truncate witness servers's repl_nodes table:\n%s\n"),
 				PQerrorMessage(witnessconn));
+		rollback_transaction(witnessconn);
+
 		return false;
 	}
 
+	/* Get current records from primary */
 	sqlquery_snprintf(sqlquery,
-					  "SELECT id, type, upstream_node_id, name, conninfo, priority, slot_name FROM %s.repl_nodes",
+					  "SELECT id, type, upstream_node_id, name, conninfo, priority, slot_name, active FROM %s.repl_nodes",
 					  get_repmgr_schema_quoted(masterconn));
 
-	log_verbose(LOG_DEBUG, "copy_configuration():\n%s\n", sqlquery);
+	log_verbose(LOG_DEBUG, "witness_copy_node_records():\n%s\n", sqlquery);
 
 	res = PQexec(masterconn, sqlquery);
 	if (PQresultStatus(res) != PGRES_TUPLES_OK)
@@ -1149,20 +1179,23 @@ copy_configuration(PGconn *masterconn, PGconn *witnessconn, char *cluster_name)
 		log_err("Unable to retrieve node records from master:\n%s\n",
 				PQerrorMessage(masterconn));
 		PQclear(res);
+		rollback_transaction(witnessconn);
+
 		return false;
 	}
 
+	/* Insert primary records into witness table */
 	for (i = 0; i < PQntuples(res); i++)
 	{
 		bool node_record_created;
 
 		log_verbose(LOG_DEBUG,
-					"copy_configuration(): writing node record for node %s (id: %s)\n",
-					PQgetvalue(res, i, 4),
+					"witness_copy_node_records(): writing node record for node %s (id: %s)\n",
+					PQgetvalue(res, i, 3),
 					PQgetvalue(res, i, 0));
 
 		node_record_created = create_node_record(witnessconn,
-												 "copy_configuration",
+												 "witness_copy_node_records",
 												 atoi(PQgetvalue(res, i, 0)),
 												 PQgetvalue(res, i, 1),
 												 strlen(PQgetvalue(res, i, 2))
@@ -1174,7 +1207,10 @@ copy_configuration(PGconn *masterconn, PGconn *witnessconn, char *cluster_name)
 												 atoi(PQgetvalue(res, i, 5)),
 												 strlen(PQgetvalue(res, i, 6))
 													? PQgetvalue(res, i, 6)
-													: NULL
+												    : NULL,
+												 (strcmp(PQgetvalue(res, i, 7), "t") == 0)
+												 	? true
+												 	: false
 												 );
 
 		if (node_record_created == false)
@@ -1183,11 +1219,16 @@ copy_configuration(PGconn *masterconn, PGconn *witnessconn, char *cluster_name)
 
 			log_err("Unable to copy node record to witness database\n%s\n",
 					PQerrorMessage(witnessconn));
+			rollback_transaction(witnessconn);
+
 			return false;
 		}
 	}
 	PQclear(res);
 
+	/* And finished */
+	commit_transaction(witnessconn);
+
 	return true;
 }
 
@@ -1200,7 +1241,7 @@ copy_configuration(PGconn *masterconn, PGconn *witnessconn, char *cluster_name)
  * XXX we should pass the record parameters as a struct.
  */
 bool
-create_node_record(PGconn *conn, char *action, int node, char *type, int upstream_node, char *cluster_name, char *node_name, char *conninfo, int priority, char *slot_name)
+create_node_record(PGconn *conn, char *action, int node, char *type, int upstream_node, char *cluster_name, char *node_name, char *conninfo, int priority, char *slot_name, bool active)
 {
 	char		sqlquery[QUERY_STR_LEN];
 	char		upstream_node_id[MAXLEN];
@@ -1241,8 +1282,8 @@ create_node_record(PGconn *conn, char *action, int node, char *type, int upstrea
 	sqlquery_snprintf(sqlquery,
 					  "INSERT INTO %s.repl_nodes "
 					  "       (id, type, upstream_node_id, cluster, "
-					  "        name, conninfo, slot_name, priority) "
-					  "VALUES (%i, '%s', %s, '%s', '%s', '%s', %s, %i) ",
+					  "        name, conninfo, slot_name, priority, active) "
+					  "VALUES (%i, '%s', %s, '%s', '%s', '%s', %s, %i, %s) ",
 					  get_repmgr_schema_quoted(conn),
 					  node,
 					  type,
@@ -1251,7 +1292,8 @@ create_node_record(PGconn *conn, char *action, int node, char *type, int upstrea
 					  node_name,
 					  conninfo,
 					  slot_name_buf,
-					  priority);
+					  priority,
+					  active == true ? "TRUE" : "FALSE");
 
 	log_verbose(LOG_DEBUG, "create_node_record(): %s\n", sqlquery);
 
@@ -1291,7 +1333,7 @@ delete_node_record(PGconn *conn, int node, char *action)
 
 	if (action != NULL)
 	{
-		log_verbose(LOG_DEBUG, "create_node_record(): action is \"%s\"\n", action);
+		log_verbose(LOG_DEBUG, "delete_node_record(): action is \"%s\"\n", action);
 	}
 
 	res = PQexec(conn, sqlquery);

dbutils.h

@@ -115,14 +115,14 @@ int			wait_connection_availability(PGconn *conn, long long timeout);
 bool		cancel_query(PGconn *conn, int timeout);
 char       *get_repmgr_schema(void);
 char       *get_repmgr_schema_quoted(PGconn *conn);
-bool		create_replication_slot(PGconn *conn, char *slot_name);
+bool		create_replication_slot(PGconn *conn, char *slot_name, int server_version_num);
 int			get_slot_record(PGconn *conn, char *slot_name, t_replication_slot *record);
 bool		drop_replication_slot(PGconn *conn, char *slot_name);
 bool		start_backup(PGconn *conn, char *first_wal_segment, bool fast_checkpoint);
 bool		stop_backup(PGconn *conn, char *last_wal_segment);
 bool		set_config_bool(PGconn *conn, const char *config_param, bool state);
-bool		copy_configuration(PGconn *masterconn, PGconn *witnessconn, char *cluster_name);
-bool		create_node_record(PGconn *conn, char *action, int node, char *type, int upstream_node, char *cluster_name, char *node_name, char *conninfo, int priority, char *slot_name);
+bool		witness_copy_node_records(PGconn *masterconn, PGconn *witnessconn, char *cluster_name);
+bool		create_node_record(PGconn *conn, char *action, int node, char *type, int upstream_node, char *cluster_name, char *node_name, char *conninfo, int priority, char *slot_name, bool active);
 bool		delete_node_record(PGconn *conn, int node, char *action);
 int			get_node_record(PGconn *conn, char *cluster, int node_id, t_node_info *node_info);
 bool        update_node_record_status(PGconn *conn, char *cluster_name, int this_node_id, char *type, int upstream_node_id, bool active);
@@ -133,3 +133,4 @@ int		    get_node_replication_state(PGconn *conn, char *node_name, char *output)
 t_server_type parse_node_type(const char *type);
 int			get_data_checksum_version(const char *data_directory);
 #endif
+

errcode.h

@@ -37,5 +37,6 @@
 #define ERR_BAD_BASEBACKUP 14
 #define ERR_INTERNAL 15
 #define ERR_MONITORING_FAIL 16
+#define ERR_BAD_BACKUP_LABEL 17
 
 #endif   /* _ERRCODE_H_ */

repmgr.c

@@ -43,7 +43,6 @@
 #include "repmgr.h"
 
 #include <sys/types.h>
-#include <dirent.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/stat.h>
@@ -122,6 +121,8 @@ static bool remote_command(const char *host, const char *user, const char *comma
 static void format_db_cli_params(const char *conninfo, char *output);
 static bool copy_file(const char *old_filename, const char *new_filename);
 
+static void read_backup_label(const char *local_data_directory, struct BackupLabel *out_backup_label);
+
 /* Global variables */
 static const char *keywords[6];
 static const char *values[6];
@@ -147,6 +148,7 @@ static char  path_buf[MAXLEN] = "";
 ErrorList	cli_errors = { NULL, NULL };
 ErrorList	cli_warnings = { NULL, NULL };
 
+static	struct BackupLabel backup_label;
 
 int
 main(int argc, char **argv)
@@ -159,6 +161,8 @@ main(int argc, char **argv)
 		{"username", required_argument, NULL, 'U'},
 		{"superuser", required_argument, NULL, 'S'},
 		{"data-dir", required_argument, NULL, 'D'},
+		/* alias for -D/--data-dir, following pg_ctl usage */
+		{"pgdata", required_argument, NULL, 'D'},
 		/* -l/--local-port is deprecated */
 		{"local-port", required_argument, NULL, 'l'},
 		{"config-file", required_argument, NULL, 'f'},
@@ -175,7 +179,7 @@ main(int argc, char **argv)
 		{"terse", required_argument, NULL, 't'},
 		{"mode", required_argument, NULL, 'm'},
 		{"remote-config-file", required_argument, NULL, 'C'},
-		/* deprecated from 3.2; replaced with -P/----pwprompt */
+		/* deprecated from 3.2; replaced with -P/--pwprompt */
 		{"initdb-no-pwprompt", no_argument, NULL, 1},
 		{"check-upstream-config", no_argument, NULL, 2},
 		{"recovery-min-apply-delay", required_argument, NULL, 3},
@@ -292,7 +296,7 @@ main(int argc, char **argv)
 				strncpy(runtime_options.superuser, optarg, MAXLEN);
 				break;
 			case 'D':
-				strncpy(runtime_options.dest_dir, optarg, MAXFILENAME);
+				strncpy(runtime_options.dest_dir, optarg, MAXPGPATH);
 				break;
 			case 'l':
 				/* -l/--local-port is deprecated */
@@ -416,7 +420,7 @@ main(int argc, char **argv)
 			case 6:
 				if (optarg != NULL)
 				{
-					strncpy(runtime_options.pg_rewind, optarg, MAXFILENAME);
+					strncpy(runtime_options.pg_rewind, optarg, MAXPGPATH);
 				}
 				pg_rewind_supplied = true;
 				break;
@@ -1071,7 +1075,8 @@ do_master_register(void)
 										options.node_name,
 										options.conninfo,
 										options.priority,
-										repmgr_slot_name_ptr);
+										repmgr_slot_name_ptr,
+										true);
 
 	if (record_created == false)
 	{
@@ -1172,9 +1177,8 @@ do_standby_register(void)
 										options.node_name,
 										options.conninfo,
 										options.priority,
-										repmgr_slot_name_ptr);
-
-
+										repmgr_slot_name_ptr,
+										true);
 
 	if (record_created == false)
 	{
@@ -1307,29 +1311,30 @@ do_standby_clone(void)
 	bool		target_directory_provided = false;
 	bool		external_config_file_copy_required = false;
 
-	char		master_data_directory[MAXFILENAME];
-	char		local_data_directory[MAXFILENAME];
+	char		master_data_directory[MAXPGPATH];
+	char		local_data_directory[MAXPGPATH];
 
-	char		master_config_file[MAXFILENAME] = "";
-	char		local_config_file[MAXFILENAME] = "";
+	char		master_config_file[MAXPGPATH] = "";
+	char		local_config_file[MAXPGPATH] = "";
 	bool		config_file_outside_pgdata = false;
 
-	char		master_hba_file[MAXFILENAME] = "";
-	char		local_hba_file[MAXFILENAME] = "";
+	char		master_hba_file[MAXPGPATH] = "";
+	char		local_hba_file[MAXPGPATH] = "";
 	bool		hba_file_outside_pgdata = false;
 
-	char		master_ident_file[MAXFILENAME] = "";
-	char		local_ident_file[MAXFILENAME] = "";
+	char		master_ident_file[MAXPGPATH] = "";
+	char		local_ident_file[MAXPGPATH] = "";
 	bool		ident_file_outside_pgdata = false;
 
-	char		master_control_file[MAXFILENAME] = "";
-	char		local_control_file[MAXFILENAME] = "";
+	char		master_control_file[MAXPGPATH] = "";
+	char		local_control_file[MAXPGPATH] = "";
 
 	char	   *first_wal_segment = NULL;
 	char	   *last_wal_segment = NULL;
 
 	PQExpBufferData event_details;
 
+
 	/*
 	 * If dest_dir (-D/--pgdata) was provided, this will become the new data
 	 * directory (otherwise repmgr will default to the same directory as on the
@@ -1491,7 +1496,7 @@ do_standby_clone(void)
 	{
 		if (strcmp(PQgetvalue(res, i, 0), "data_directory") == 0)
 		{
-			strncpy(master_data_directory, PQgetvalue(res, i, 1), MAXFILENAME);
+			strncpy(master_data_directory, PQgetvalue(res, i, 1), MAXPGPATH);
 		}
 		else if (strcmp(PQgetvalue(res, i, 0), "config_file") == 0)
 		{
@@ -1499,7 +1504,7 @@ do_standby_clone(void)
 			{
 				config_file_outside_pgdata = true;
 				external_config_file_copy_required = true;
-				strncpy(master_config_file, PQgetvalue(res, i, 1), MAXFILENAME);
+				strncpy(master_config_file, PQgetvalue(res, i, 1), MAXPGPATH);
 			}
 		}
 		else if (strcmp(PQgetvalue(res, i, 0), "hba_file") == 0)
@@ -1508,7 +1513,7 @@ do_standby_clone(void)
 			{
 				hba_file_outside_pgdata  = true;
 				external_config_file_copy_required = true;
-				strncpy(master_hba_file, PQgetvalue(res, i, 1), MAXFILENAME);
+				strncpy(master_hba_file, PQgetvalue(res, i, 1), MAXPGPATH);
 			}
 		}
 		else if (strcmp(PQgetvalue(res, i, 0), "ident_file") == 0)
@@ -1517,7 +1522,7 @@ do_standby_clone(void)
 			{
 				ident_file_outside_pgdata = true;
 				external_config_file_copy_required = true;
-				strncpy(master_ident_file, PQgetvalue(res, i, 1), MAXFILENAME);
+				strncpy(master_ident_file, PQgetvalue(res, i, 1), MAXPGPATH);
 			}
 		}
 		else
@@ -1533,20 +1538,20 @@ do_standby_clone(void)
 	 */
 	if (target_directory_provided)
 	{
-		strncpy(local_data_directory, runtime_options.dest_dir, MAXFILENAME);
-		strncpy(local_config_file, runtime_options.dest_dir, MAXFILENAME);
-		strncpy(local_hba_file, runtime_options.dest_dir, MAXFILENAME);
-		strncpy(local_ident_file, runtime_options.dest_dir, MAXFILENAME);
+		strncpy(local_data_directory, runtime_options.dest_dir, MAXPGPATH);
+		strncpy(local_config_file, runtime_options.dest_dir, MAXPGPATH);
+		strncpy(local_hba_file, runtime_options.dest_dir, MAXPGPATH);
+		strncpy(local_ident_file, runtime_options.dest_dir, MAXPGPATH);
 	}
 	/*
 	 * Otherwise use the same data directory as on the remote host
 	 */
 	else
 	{
-		strncpy(local_data_directory, master_data_directory, MAXFILENAME);
-		strncpy(local_config_file, master_config_file, MAXFILENAME);
-		strncpy(local_hba_file, master_hba_file, MAXFILENAME);
-		strncpy(local_ident_file, master_ident_file, MAXFILENAME);
+		strncpy(local_data_directory, master_data_directory, MAXPGPATH);
+		strncpy(local_config_file, master_config_file, MAXPGPATH);
+		strncpy(local_hba_file, master_hba_file, MAXPGPATH);
+		strncpy(local_ident_file, master_ident_file, MAXPGPATH);
 
 		log_notice(_("setting data directory to: %s\n"), local_data_directory);
 		log_hint(_("use -D/--data-dir to explicitly specify a data directory\n"));
@@ -1586,7 +1591,7 @@ do_standby_clone(void)
 	 */
 	if (options.use_replication_slots)
 	{
-		if (create_replication_slot(upstream_conn, repmgr_slot_name) == false)
+		if (create_replication_slot(upstream_conn, repmgr_slot_name, server_version_num) == false)
 		{
 			PQfinish(upstream_conn);
 			exit(ERR_DB_QUERY);
@@ -1654,13 +1659,25 @@ do_standby_clone(void)
 		r = copy_remote_files(runtime_options.host, runtime_options.remote_user,
 							  master_data_directory, local_data_directory,
 							  true, server_version_num);
-		if (r != 0)
+		/*
+		  Exit code 0 means no error, but we want to ignore exit code 24 as well
+		  as rsync returns that code on "Partial transfer due to vanished source files".
+		  It's quite common for this to happen on the data directory, particularly
+		  with long running rsync on a busy server.
+		*/
+		if (r != 0 && r != 24)
 		{
 			log_warning(_("standby clone: failed copying master data directory '%s'\n"),
 						master_data_directory);
 			goto stop_backup;
 		}
 
+		/* Read backup label copied from primary */
+		/* XXX ensure this function does not exit on error as we'd need to stop the backup */
+		read_backup_label(local_data_directory, &backup_label);
+
+		printf("Label: %s; file: %s\n", backup_label.label, backup_label.start_wal_file);
+
 		/* Handle tablespaces */
 
 		sqlquery_snprintf(sqlquery,
@@ -1728,6 +1745,18 @@ do_standby_clone(void)
 								  tblspc_dir_src.data, tblspc_dir_dst.data,
 								  true, server_version_num);
 
+			/*
+			  Exit code 0 means no error, but we want to ignore exit code 24 as well
+			  as rsync returns that code on "Partial transfer due to vanished source files".
+			  It's quite common for this to happen on the data directory, particularly
+			  with long running rsync on a busy server.
+			*/
+			if (r != 0 && r != 24)
+			{
+			       log_warning(_("standby clone: failed copying tablespace directory '%s'\n"),
+					            tblspc_dir_src.data);
+			       goto stop_backup;
+			}
 
 			/* Update symlinks in pg_tblspc */
 			if (mapping_found == true)
@@ -1952,44 +1981,55 @@ stop_backup:
 		exit(retval);
 	}
 
-
 	/*
 	 * Clean up any $PGDATA subdirectories which may contain
 	 * files which won't be removed by rsync and which could
 	 * be stale or are otherwise not required
 	 */
-	if (runtime_options.rsync_only && runtime_options.force)
+	if (runtime_options.rsync_only)
 	{
 		char	script[MAXLEN];
+		char	label_path[MAXPGPATH];
 
-		/*
-		 * Remove any existing WAL from the target directory, since
-		 * rsync's --exclude option doesn't do it.
-		 */
-		maxlen_snprintf(script, "rm -rf %s/pg_xlog/*",
-						local_data_directory);
-		r = system(script);
-		if (r != 0)
+		if (runtime_options.force)
 		{
-			log_err(_("unable to empty local WAL directory %s/pg_xlog/\n"),
-					local_data_directory);
-			exit(ERR_BAD_RSYNC);
+			/*
+			 * Remove any existing WAL from the target directory, since
+			 * rsync's --exclude option doesn't do it.
+			 */
+			maxlen_snprintf(script, "rm -rf %s/pg_xlog/*",
+							local_data_directory);
+			r = system(script);
+			if (r != 0)
+			{
+				log_err(_("unable to empty local WAL directory %s/pg_xlog/\n"),
+						local_data_directory);
+				exit(ERR_BAD_RSYNC);
+			}
 		}
 
 		/*
-		 * Remove any replication slot directories; this matches the
-		 * behaviour a base backup, which would result in an empty
-		 * pg_replslot directory.
+		 * Remove any existing replication slot directories from previous use
+		 * of this data directory; this matches the behaviour of a fresh
+		 * pg_basebackup, which would usually result in an empty pg_replslot
+		 * directory.
+		 *
+		 * If the backup label contains a nonzero
+		 * 'MIN FAILOVER SLOT LSN' entry we retain the slots and let
+		 * the server clean them up instead, matching pg_basebackup's
+		 * behaviour when failover slots are enabled.
 		 *
 		 * NOTE: watch out for any changes in the replication
 		 * slot directory name (as of 9.4: "pg_replslot") and
 		 * functionality of replication slots
 		 */
-
-		if (server_version_num >= 90400)
+		if (server_version_num >= 90400 &&
+				backup_label.min_failover_slot_lsn == InvalidXLogRecPtr)
 		{
 			maxlen_snprintf(script, "rm -rf %s/pg_replslot/*",
 							local_data_directory);
+
+			log_debug("deleting pg_replslot directory contents\n");
 			r = system(script);
 			if (r != 0)
 			{
@@ -1998,6 +2038,13 @@ stop_backup:
 				exit(ERR_BAD_RSYNC);
 			}
 		}
+
+		/* delete the backup label file copied from the primary */
+		maxlen_snprintf(label_path, "%s/backup_label", local_data_directory);
+		if (0 && unlink(label_path) < 0 && errno != ENOENT)
+		{
+			log_warning(_("unable to delete backup label file %s\n"), label_path);
+		}
 	}
 
 	/* Finally, write the recovery.conf file */
@@ -2013,9 +2060,9 @@ stop_backup:
 	}
 
 	/*
-	 * XXX It might be nice to provide the following options:
-	 * - have repmgr start the daemon automatically
-	 * - provide a custom pg_ctl command
+	 * XXX It might be nice to provide an options to have repmgr start
+	 * the PostgreSQL server automatically (e.g. with a custom pg_ctl
+	 * command)
 	 */
 
 	log_notice(_("you can now start your PostgreSQL server\n"));
@@ -2029,7 +2076,28 @@ stop_backup:
 		log_hint(_("for example : /etc/init.d/postgresql start\n"));
 	}
 
-	/* Log the event - if we could connect to the primary */
+
+	/*
+	 * XXX forgetting to (re) register the standby is a frequent cause
+	 * of error; we should consider having repmgr automatically
+	 * register the standby, either by default with an option
+	 * "--no-register", or an option "--register".
+	 *
+	 * Note that "repmgr standby register" requires the standby to
+	 * be running - if not, and we just update the node record,
+	 * we'd have an incorrect representation of the replication cluster.
+	 * Best combined with an automatic start of the server (see note
+	 * above)
+	 */
+
+	/*
+	 * XXX detect whether a record exists for this node already, and
+	 * add a hint about using the -F/--force.
+	 */
+
+	log_hint(_("After starting the server, you need to register this standby with \"repmgr standby register\"\n"));
+
+	/* Log the event - if we can connect to the primary */
 
 	if (primary_conn != NULL)
 	{
@@ -2061,6 +2129,159 @@ stop_backup:
 	exit(retval);
 }
 
+static bool
+parse_lsn(XLogRecPtr *ptr, const char *str)
+{
+	uint32 high, low;
+
+	if (sscanf(str, "%x/%x", &high, &low) != 2)
+		return false;
+
+	*ptr = (((XLogRecPtr)high) << 32) + (XLogRecPtr)low;
+
+	return true;
+}
+
+static XLogRecPtr
+parse_label_lsn(const char *label_key, const char *label_value)
+{
+	XLogRecPtr ptr;
+
+	if (!parse_lsn(&ptr, label_value))
+	{
+		log_err(_("Couldn't parse backup label entry \"%s: %s\" as lsn"),
+				label_key, label_value);
+
+		exit(ERR_BAD_BACKUP_LABEL);
+	}
+
+	return ptr;
+}
+
+/*======================================
+ * Read entries of interest from the backup label.
+ *
+ * Sample backup label (with failover slots):
+ *
+ *		START WAL LOCATION: 0/6000028 (file 000000010000000000000006)
+ *		CHECKPOINT LOCATION: 0/6000060
+ *		BACKUP METHOD: streamed
+ *		BACKUP FROM: master
+ *		START TIME: 2016-03-30 12:18:12 AWST
+ *		LABEL: pg_basebackup base backup
+ *		MIN FAILOVER SLOT LSN: 0/5000000
+ *
+ *======================================
+ */
+static void
+read_backup_label(const char *local_data_directory, struct BackupLabel *out_backup_label)
+{
+	char label_path[MAXPGPATH];
+	FILE *label_file;
+	int  nmatches = 0;
+
+	char line[MAXLEN];
+
+	out_backup_label->start_wal_location = InvalidXLogRecPtr;
+	out_backup_label->start_wal_file[0] = '\0';
+	out_backup_label->checkpoint_location = InvalidXLogRecPtr;
+	out_backup_label->backup_from[0] = '\0';
+	out_backup_label->backup_method[0] = '\0';
+	out_backup_label->start_time[0] = '\0';
+	out_backup_label->label[0] = '\0';
+	out_backup_label->min_failover_slot_lsn = InvalidXLogRecPtr;
+
+	maxlen_snprintf(label_path, "%s/backup_label", local_data_directory);
+
+	label_file = fopen(label_path, "r");
+	if (label_file == NULL)
+	{
+		log_err(_("read_backup_label: could not open backup label file %s: %s"),
+				label_path, strerror(errno));
+		exit(ERR_BAD_BACKUP_LABEL);
+	}
+
+	log_info(_("read_backup_label: parsing backup label file '%s'\n"),
+			 label_path);
+
+	while(fgets(line, sizeof line, label_file) != NULL)
+	{
+		char label_key[MAXLEN];
+		char label_value[MAXLEN];
+		char newline;
+
+		nmatches = sscanf(line, "%" MAXLEN_STR "[^:]: %" MAXLEN_STR "[^\n]%c",
+						  label_key, label_value, &newline);
+
+		if (nmatches != 3)
+			break;
+
+		if (newline != '\n')
+		{
+			log_err(_("read_backup_label: line too long in backup label file. Line begins \"%s: %s\""),
+					label_key, label_value);
+			exit(ERR_BAD_BACKUP_LABEL);
+		}
+
+		log_debug("standby clone: got backup label entry \"%s: %s\"\n",
+				label_key, label_value);
+
+		if (strcmp(label_key, "START WAL LOCATION") == 0)
+		{
+			char start_wal_location[MAXLEN];
+			char wal_filename[MAXLEN];
+
+			nmatches = sscanf(label_value, "%" MAXLEN_STR "s (file %" MAXLEN_STR "[^)]", start_wal_location, wal_filename);
+			if (nmatches != 2)
+			{
+				log_err(_("read_backup_label: unable to parse \"START WAL LOCATION\" in backup label\n"));
+				exit(ERR_BAD_BACKUP_LABEL);
+			}
+			out_backup_label->start_wal_location =
+				parse_label_lsn(&label_key[0], start_wal_location);
+
+			(void) strncpy(out_backup_label->start_wal_file, wal_filename, MAXLEN);
+			out_backup_label->start_wal_file[MAXLEN-1] = '\0';
+		}
+		else if (strcmp(label_key, "CHECKPOINT LOCATION") == 0)
+		{
+			out_backup_label->checkpoint_location =
+				parse_label_lsn(&label_key[0], &label_value[0]);
+		}
+		else if (strcmp(label_key, "BACKUP METHOD") == 0)
+		{
+			(void) strncpy(out_backup_label->backup_method, label_value, MAXLEN);
+			out_backup_label->backup_method[MAXLEN-1] = '\0';
+		}
+		else if (strcmp(label_key, "BACKUP FROM") == 0)
+		{
+			(void) strncpy(out_backup_label->backup_from, label_value, MAXLEN);
+			out_backup_label->backup_from[MAXLEN-1] = '\0';
+		}
+		else if (strcmp(label_key, "START TIME") == 0)
+		{
+			(void) strncpy(out_backup_label->start_time, label_value, MAXLEN);
+			out_backup_label->start_time[MAXLEN-1] = '\0';
+		}
+		else if (strcmp(label_key, "LABEL") == 0)
+		{
+			(void) strncpy(out_backup_label->label, label_value, MAXLEN);
+			out_backup_label->label[MAXLEN-1] = '\0';
+		}
+		else if (strcmp(label_key, "MIN FAILOVER SLOT LSN") == 0)
+		{
+			out_backup_label->min_failover_slot_lsn =
+				parse_label_lsn(&label_key[0], &label_value[0]);
+		}
+		else
+		{
+			log_info("read_backup_label: ignored unrecognised backup label entry \"%s: %s\"",
+					label_key, label_value);
+		}
+	}
+
+	(void) fclose(label_file);
+}
 
 static void
 do_standby_promote(void)
@@ -2234,7 +2455,7 @@ do_standby_follow(void)
 
 	int			r,
 				retval;
-	char		data_dir[MAXFILENAME];
+	char		data_dir[MAXPGPATH];
 
 	bool        success;
 
@@ -2317,7 +2538,7 @@ do_standby_follow(void)
 
 		master_id = get_master_node_id(master_conn, options.cluster_name);
 
-		strncpy(data_dir, runtime_options.dest_dir, MAXFILENAME);
+		strncpy(data_dir, runtime_options.dest_dir, MAXPGPATH);
 	}
 
 
@@ -2349,7 +2570,9 @@ do_standby_follow(void)
 
 	if (options.use_replication_slots)
 	{
-		if (create_replication_slot(master_conn, repmgr_slot_name) == false)
+ 		int	server_version_num = get_server_version(master_conn, NULL);
+
+		if (create_replication_slot(master_conn, repmgr_slot_name, server_version_num) == false)
 		{
 			PQExpBufferData event_details;
 			initPQExpBuffer(&event_details);
@@ -2854,8 +3077,8 @@ do_standby_switchover(void)
 	 */
 
 	maxlen_snprintf(command,
-					"%s/pg_ctl -D %s -m %s -W stop >/dev/null 2>&1 && echo 1 || echo 0",
-					pg_bindir,
+					"%s -D %s -m %s -W stop >/dev/null 2>&1 && echo 1 || echo 0",
+					make_pg_path("pg_ctl"),
 					remote_data_directory,
 					runtime_options.pg_ctl_mode);
 
@@ -3297,10 +3520,17 @@ do_standby_restore_config(void)
 	}
 
 	while ((arcdir_ent = readdir(arcdir)) != NULL) {
+		struct stat statbuf;
+		char arcdir_ent_path[MAXPGPATH];
 		PQExpBufferData src_file;
 		PQExpBufferData dst_file;
 
-		if (arcdir_ent->d_type != DT_REG)
+		snprintf(arcdir_ent_path, MAXPGPATH,
+				 "%s/%s",
+				 runtime_options.config_archive_dir,
+				 arcdir_ent->d_name);
+
+		if (stat(arcdir_ent_path, &statbuf) == 0 && !S_ISREG(statbuf.st_mode))
 		{
 			continue;
 		}
@@ -3764,7 +3994,8 @@ do_witness_create(void)
 										options.node_name,
 										options.conninfo,
 										options.priority,
-										NULL);
+										NULL,
+										true);
 
 	if (record_created == false)
 	{
@@ -3781,7 +4012,7 @@ do_witness_create(void)
 
 
 	/* copy configuration from master, only repl_nodes is needed */
-	if (!copy_configuration(masterconn, witnessconn, options.cluster_name))
+	if (!witness_copy_node_records(masterconn, witnessconn, options.cluster_name))
 	{
 		create_event_record(masterconn,
 							&options,
@@ -4042,6 +4273,7 @@ test_ssh_connection(char *host, char *remote_user)
 	return r;
 }
 
+
 static int
 copy_remote_files(char *host, char *remote_user, char *remote_path,
 				  char *local_path, bool is_directory, int server_version_num)
@@ -4086,6 +4318,9 @@ copy_remote_files(char *host, char *remote_user, char *remote_path,
 	 * See function 'sendDir()' in 'src/backend/replication/basebackup.c' -
 	 * we're basically simulating what pg_basebackup does, but with rsync rather
 	 * than the BASEBACKUP replication protocol command.
+	 *
+	 * *However* currently we'll always copy the contents of the 'pg_replslot'
+	 * directory and delete later if appropriate.
 	 */
 	if (is_directory)
 	{
@@ -4114,12 +4349,6 @@ copy_remote_files(char *host, char *remote_user, char *remote_path,
 		appendPQExpBuffer(&rsync_flags, "%s",
 						  " --exclude=pg_xlog/* --exclude=pg_log/* --exclude=pg_stat_tmp/*");
 
-		if (server_version_num >= 90400)
-		{
-			appendPQExpBuffer(&rsync_flags, "%s",
-							  " --exclude=pg_replslot/*");
-		}
-
 		maxlen_snprintf(script, "rsync %s %s:%s/* %s",
 						rsync_flags.data, host_string, remote_path, local_path);
 	}
@@ -4478,7 +4707,7 @@ create_schema(PGconn *conn)
 					  "CREATE TABLE %s.repl_nodes (     "
 					  "  id               INTEGER PRIMARY KEY, "
 					  "  type             TEXT    NOT NULL CHECK (type IN('master','standby','witness')), "
-					  "  upstream_node_id INTEGER NULL REFERENCES %s.repl_nodes (id), "
+					  "  upstream_node_id INTEGER NULL REFERENCES %s.repl_nodes (id) DEFERRABLE, "
 					  "  cluster          TEXT    NOT NULL, "
 					  "  name             TEXT    NOT NULL, "
 					  "  conninfo         TEXT    NOT NULL, "
@@ -4845,22 +5074,45 @@ check_upstream_config(PGconn *conn, int server_version_num, bool exit_on_error)
 	}
 	else
 	{
-		char *levels[] = {
+		char *levels_pre96[] = {
 			"hot_standby",
 			"logical",
+			NULL,
 		};
 
-		int j = 0;
-		wal_error_message = _("parameter 'wal_level' must be set to 'hot_standby' or 'logical'");
+		/*
+		 * Note that in 9.6+, "hot_standby" and "archive" are accepted as aliases
+		 * for "replica", but current_setting() will of course always return "replica"
+		 */
+		char *levels_96plus[] = {
+			"replica",
+			"logical",
+			NULL,
+		};
 
-		for(; j < 2; j++)
+		char **levels;
+		int j = 0;
+
+		if (server_version_num < 90600)
+		{
+			levels = (char **)levels_pre96;
+			wal_error_message = _("parameter 'wal_level' must be set to 'hot_standby' or 'logical'");
+		}
+		else
+		{
+			levels = (char **)levels_96plus;
+			wal_error_message = _("parameter 'wal_level' must be set to 'replica' or 'logical'");
+		}
+
+		do
 		{
 			i = guc_set(conn, "wal_level", "=", levels[j]);
 			if (i)
 			{
 				break;
 			}
-		}
+			j++;
+		} while (levels[j] != NULL);
 	}
 
 	if (i == 0 || i == -1)

repmgr.conf.sample

@@ -15,21 +15,21 @@
 # schema (pattern: "repmgr_{cluster}"); while this name will be quoted
 # to preserve case, we recommend using lower case and avoiding whitespace
 # to facilitate easier querying of the repmgr views and tables.
-cluster=example_cluster
+#cluster=example_cluster
 
 # Node ID and name
 # (Note: we recommend to avoid naming nodes after their initial
 #  replication funcion, as this will cause confusion when e.g.
 #  "standby2" is promoted to primary)
-node=2           # a unique integer
-node_name=node2  # an arbitrary (but unique) string; we recommend using
+#node=2           # a unique integer
+#node_name=node2  # an arbitrary (but unique) string; we recommend using
                  # the server's hostname or another identifier unambiguously
                  # associated with the server to avoid confusion
 
 # Database connection information as a conninfo string
 # This must be accessible to all servers in the cluster; for details see:
 #   http://www.postgresql.org/docs/current/static/libpq-connect.html#LIBPQ-CONNSTRING
-conninfo='host=192.168.204.104 dbname=repmgr_db user=repmgr_usr'
+#conninfo='host=192.168.204.104 dbname=repmgr_db user=repmgr_usr'
 
 # Optional configuration items
 # ============================
@@ -37,15 +37,16 @@ conninfo='host=192.168.204.104 dbname=repmgr_db user=repmgr_usr'
 # Replication settings
 # ---------------------
 
-# when using cascading replication and a standby is to be connected to an
-# upstream standby, specify that node's ID with 'upstream_node'. The node
-# must exist before the new standby can be registered. If a standby is
-# to connect directly to a primary node, this parameter is not required.
-upstream_node=1
+# When using cascading replication, a standby can connect to another
+# upstream standby node which is specified by setting 'upstream_node'.
+# In that case, the upstream node must exist before the new standby
+# can be registered. If 'upstream_node' is not set, then the standby
+# will connect directly to the primary node.
+#upstream_node=1
 
 # use physical replication slots - PostgreSQL 9.4 and later only
 # (default: 0)
-use_replication_slots=0
+#use_replication_slots=0
 
 # NOTE: 'max_replication_slots' should be configured for at least the
 # number of standbys which will connect to the primary.
@@ -55,15 +56,15 @@ use_replication_slots=0
 
 # Log level: possible values are DEBUG, INFO, NOTICE, WARNING, ERR, ALERT, CRIT or EMERG
 # (default: NOTICE)
-loglevel=NOTICE
+#loglevel=NOTICE
 
 # Logging facility: possible values are STDERR or - for Syslog integration - one of LOCAL0, LOCAL1, ..., LOCAL7, USER
 # (default: STDERR)
-logfacility=STDERR
+#logfacility=STDERR
 
 # stderr can be redirected to an arbitrary file:
 #
-logfile='/var/log/repmgr/repmgr.log'
+#logfile='/var/log/repmgr/repmgr.log'
 
 # event notifications can be passed to an arbitrary external program
 # together with the following parameters:
@@ -77,12 +78,12 @@ logfile='/var/log/repmgr/repmgr.log'
 # the values provided for "%t" and "%d" will probably contain spaces,
 # so should be quoted in the provided command configuration, e.g.:
 #
-event_notification_command='/path/to/some/script %n %e %s "%t" "%d"'
+#event_notification_command='/path/to/some/script %n %e %s "%t" "%d"'
 
 # By default, all notifications will be passed; the notification types
 # can be filtered to explicitly named ones:
 #
-event_notifications=master_register,standby_register,witness_create
+#event_notifications=master_register,standby_register,witness_create
 
 
 # Environment/command settings
@@ -90,17 +91,17 @@ event_notifications=master_register,standby_register,witness_create
 
 # path to PostgreSQL binary directory (location of pg_ctl, pg_basebackup etc.)
 # (if not provided, defaults to system $PATH)
-pg_bindir=/usr/bin/
+#pg_bindir=/usr/bin/
 
 # external command options
 
-rsync_options=--archive --checksum --compress --progress --rsh="ssh -o \"StrictHostKeyChecking no\""
-ssh_options=-o "StrictHostKeyChecking no"
+#rsync_options=--archive --checksum --compress --progress --rsh="ssh -o \"StrictHostKeyChecking no\""
+#ssh_options=-o "StrictHostKeyChecking no"
 
 # external command arguments. Values shown are examples.
 
-pg_ctl_options='-s'
-pg_basebackup_options='--xlog-method=s'
+#pg_ctl_options='-s'
+#pg_basebackup_options='--xlog-method=s'
 
 
 # Standby clone settings
@@ -122,27 +123,30 @@ pg_basebackup_options='--xlog-method=s'
 # Number of seconds to wait for a response from the primary server before
 # deciding it has failed.
 
-master_response_timeout=60
+#master_response_timeout=60
 
 # Number of attempts at what interval (in seconds) to try and
 # connect to  a server to establish its status (e.g. master
 # during failover)
-reconnect_attempts=6
-reconnect_interval=10
+#reconnect_attempts=6
+#reconnect_interval=10
 
 # Autofailover options
-failover=manual     # one of 'automatic', 'manual'
+#failover=manual    # one of 'automatic', 'manual'
                     # (default: manual)
-priority=100        # a value of zero or less prevents the node being promoted to primary
+#priority=100       # a value of zero or less prevents the node being promoted to primary
                     # (default: 100)
-promote_command='repmgr standby promote -f /path/to/repmgr.conf'
-follow_command='repmgr standby follow -f /path/to/repmgr.conf -W'
+#promote_command='repmgr standby promote -f /path/to/repmgr.conf'
+#follow_command='repmgr standby follow -f /path/to/repmgr.conf -W'
 
 # monitoring interval in seconds; default is 2
-monitor_interval_secs=2
+#monitor_interval_secs=2
 
 # change wait time for primary; before we bail out and exit when the primary
 # disappears, we wait 'reconnect_attempts' * 'retry_promote_interval_secs'
 # seconds; by default this would be half an hour, as 'retry_promote_interval_secs'
 # default value is 300)
-retry_promote_interval_secs=300
+#retry_promote_interval_secs=300
+
+# Number of seconds after which the witness server resyncs the repl_nodes table
+#witness_repl_nodes_sync_interval_secs=15

repmgr.h

@@ -32,8 +32,6 @@
 #define MIN_SUPPORTED_VERSION		"9.3"
 #define MIN_SUPPORTED_VERSION_NUM	90300
 
-#include "config.h"
-#define MAXFILENAME		1024
 #define ERRBUFF_SIZE	512
 
 #define DEFAULT_WAL_KEEP_SEGMENTS	"5000"
@@ -57,8 +55,8 @@ typedef struct
 	char		dbname[MAXLEN];
 	char		host[MAXLEN];
 	char		username[MAXLEN];
-	char		dest_dir[MAXFILENAME];
-	char		config_file[MAXFILENAME];
+	char		dest_dir[MAXPGPATH];
+	char		config_file[MAXPGPATH];
 	char		remote_user[MAXLEN];
 	char		superuser[MAXLEN];
 	char		wal_keep_segments[MAXLEN];
@@ -81,7 +79,7 @@ typedef struct
 
 	/* parameter used by STANDBY SWITCHOVER */
 	char		remote_config_file[MAXLEN];
-	char		pg_rewind[MAXFILENAME];
+	char		pg_rewind[MAXPGPATH];
 	/* parameter used by STANDBY {ARCHIVE_CONFIG | RESTORE_CONFIG} */
 	char		config_archive_dir[MAXLEN];
 	/* parameter used by CLUSTER CLEANUP */
@@ -98,6 +96,18 @@ typedef struct
 
 #define T_RUNTIME_OPTIONS_INITIALIZER { "", "", "", "", "", "", "", DEFAULT_WAL_KEEP_SEGMENTS, false, false, false, false, false, false, false, false, false, "smart", "", "", "", "", "", 0, "", "", "", false }
 
+struct BackupLabel
+{
+	XLogRecPtr start_wal_location;
+	char start_wal_file[MAXLEN];
+	XLogRecPtr checkpoint_location;
+	char backup_from[MAXLEN];
+	char backup_method[MAXLEN];
+	char start_time[MAXLEN];
+	char label[MAXLEN];
+	XLogRecPtr min_failover_slot_lsn;
+};
+
 extern char		repmgr_schema[MAXLEN];
 extern bool		config_file_found;
 

repmgrd.c

@@ -274,7 +274,14 @@ main(int argc, char **argv)
 	/* Retrieve record for this node from the local database */
 	node_info = get_node_info(my_local_conn, local_options.cluster_name, local_options.node);
 
-	/* No node record found - exit gracefully */
+	/*
+	 * No node record found - exit gracefully
+	 *
+	 * Note: it's highly unlikely this situation will occur when starting
+	 * repmgrd on a witness, unless someone goes to the trouble of
+	 * deleting the node record from the previously copied table.
+	 */
+
 	if (node_info.node_id == NODE_NOT_FOUND)
 	{
 		log_err(_("No metadata record found for this node - terminating\n"));
@@ -291,9 +298,12 @@ main(int argc, char **argv)
 	 */
 	do
 	{
+		/* Timer for repl_nodes synchronisation interval */
+		int sync_repl_nodes_elapsed = 0;
+
 		/*
 		 * Set my server mode, establish a connection to master and start
-		 * monitor
+		 * monitoring
 		 */
 
 		switch (node_info.type)
@@ -393,8 +403,8 @@ main(int argc, char **argv)
 						 local_options.cluster_name);
 
 				master_conn = get_master_connection(my_local_conn,
-													 local_options.cluster_name,
-													 &master_options.node, NULL);
+													local_options.cluster_name,
+													&master_options.node, NULL);
 
 				if (master_conn == NULL)
 				{
@@ -402,8 +412,7 @@ main(int argc, char **argv)
 					initPQExpBuffer(&errmsg);
 
 					appendPQExpBuffer(&errmsg,
-									  _("unable to connect to master node '%s'"),
-									  master_options.node_name);
+									  _("unable to connect to master node"));
 
 					log_err("%s\n", errmsg.data);
 
@@ -466,6 +475,24 @@ main(int argc, char **argv)
 
 					sleep(local_options.monitor_interval_secs);
 
+					/*
+					 * On a witness node, regularly resync the repl_nodes table
+					 * to keep up with any changes on the primary
+					 *
+					 * TODO: only resync the table if changes actually detected
+					 */
+					if (node_info.type == WITNESS)
+					{
+						sync_repl_nodes_elapsed += local_options.monitor_interval_secs;
+						log_debug(_("seconds since last node record sync: %i (sync interval: %i)\n"), sync_repl_nodes_elapsed, local_options.witness_repl_nodes_sync_interval_secs);
+						if(sync_repl_nodes_elapsed >= local_options.witness_repl_nodes_sync_interval_secs)
+						{
+							log_debug(_("Resyncing repl_nodes table\n"));
+							witness_copy_node_records(master_conn, my_local_conn, local_options.cluster_name);
+							sync_repl_nodes_elapsed = 0;
+						}
+					}
+
 					if (got_SIGHUP)
 					{
 						/*
@@ -480,6 +507,7 @@ main(int argc, char **argv)
 						}
 						got_SIGHUP = false;
 					}
+
 					if (failover_done)
 					{
 						log_debug(_("standby check loop will terminate\n"));
@@ -572,7 +600,7 @@ witness_monitor(void)
 				 * XXX it would be neat to be able to handle this with e.g. table-based
 				 * logical replication
 				 */
-				copy_configuration(master_conn, my_local_conn, local_options.cluster_name);
+				witness_copy_node_records(master_conn, my_local_conn, local_options.cluster_name);
 
 				break;
 			}
@@ -668,15 +696,15 @@ standby_monitor(void)
 	PGresult   *res;
 	char		monitor_standby_timestamp[MAXLEN];
 	char		last_wal_master_location[MAXLEN];
-	char		last_wal_standby_received[MAXLEN];
-	char		last_wal_standby_applied[MAXLEN];
-	char		last_wal_standby_applied_timestamp[MAXLEN];
-	bool		last_wal_standby_received_gte_replayed;
+	char		last_xlog_receive_location[MAXLEN];
+	char		last_xlog_replay_location[MAXLEN];
+	char		last_xact_replay_timestamp[MAXLEN];
+	bool		last_xlog_receive_location_gte_replayed;
 	char		sqlquery[QUERY_STR_LEN];
 
-	XLogRecPtr	lsn_master;
-	XLogRecPtr	lsn_standby_received;
-	XLogRecPtr	lsn_standby_applied;
+	XLogRecPtr	lsn_master_current_xlog_location;
+	XLogRecPtr	lsn_last_xlog_receive_location;
+	XLogRecPtr	lsn_last_xlog_replay_location;
 
 	int			connection_retries,
 				ret;
@@ -970,10 +998,10 @@ standby_monitor(void)
 	}
 
 	strncpy(monitor_standby_timestamp, PQgetvalue(res, 0, 0), MAXLEN);
-	strncpy(last_wal_standby_received, PQgetvalue(res, 0, 1), MAXLEN);
-	strncpy(last_wal_standby_applied, PQgetvalue(res, 0, 2), MAXLEN);
-	strncpy(last_wal_standby_applied_timestamp, PQgetvalue(res, 0, 3), MAXLEN);
-	last_wal_standby_received_gte_replayed = (strcmp(PQgetvalue(res, 0, 4), "t") == 0)
+	strncpy(last_xlog_receive_location, PQgetvalue(res, 0, 1), MAXLEN);
+	strncpy(last_xlog_replay_location, PQgetvalue(res, 0, 2), MAXLEN);
+	strncpy(last_xact_replay_timestamp, PQgetvalue(res, 0, 3), MAXLEN);
+	last_xlog_receive_location_gte_replayed = (strcmp(PQgetvalue(res, 0, 4), "t") == 0)
 		? true
 		: false;
 
@@ -982,13 +1010,13 @@ standby_monitor(void)
 	/*
 	 * In the unusual event of a standby becoming disconnected from the primary,
 	 * while this repmgrd remains connected to the primary,  subtracting
-	 * "lsn_standby_applied" from "lsn_standby_received" and coercing to
+	 * "last_xlog_replay_location" from "lsn_last_xlog_receive_location" and coercing to
 	 * (long long unsigned int) will result in a meaningless, very large
 	 * value which will overflow a BIGINT column and spew error messages into the
 	 * PostgreSQL log. In the absence of a better strategy, skip attempting
 	 * to insert a monitoring record.
 	 */
-	if (last_wal_standby_received_gte_replayed == false)
+	if (last_xlog_receive_location_gte_replayed == false)
 	{
 		log_verbose(LOG_WARNING,
 					"Invalid replication_lag value calculated - is this standby connected to its upstream?\n");
@@ -1010,29 +1038,40 @@ standby_monitor(void)
 	PQclear(res);
 
 	/* Calculate the lag */
-	lsn_master = lsn_to_xlogrecptr(last_wal_master_location, NULL);
-	lsn_standby_received = lsn_to_xlogrecptr(last_wal_standby_received, NULL);
-	lsn_standby_applied = lsn_to_xlogrecptr(last_wal_standby_applied, NULL);
+	lsn_master_current_xlog_location = lsn_to_xlogrecptr(last_wal_master_location, NULL);
+	lsn_last_xlog_receive_location = lsn_to_xlogrecptr(last_xlog_receive_location, NULL);
+	lsn_last_xlog_replay_location = lsn_to_xlogrecptr(last_xlog_replay_location, NULL);
 
 	/*
 	 * Build the SQL to execute on master
 	 */
 	sqlquery_snprintf(sqlquery,
 					  "INSERT INTO %s.repl_monitor "
-					  "           (primary_node, standby_node, "
-					  "            last_monitor_time, last_apply_time, "
-					  "            last_wal_primary_location, last_wal_standby_location, "
-					  "            replication_lag, apply_lag ) "
-					  "     VALUES(%d, %d, "
-					  "            '%s'::TIMESTAMP WITH TIME ZONE, '%s'::TIMESTAMP WITH TIME ZONE, "
-					  "            '%s', '%s', "
-					  "            %llu, %llu) ",
+					  "           (primary_node, "
+					  "            standby_node, "
+					  "            last_monitor_time, "
+					  "            last_apply_time, "
+					  "            last_wal_primary_location, "
+					  "            last_wal_standby_location, "
+					  "            replication_lag, "
+					  "            apply_lag ) "
+					  "     VALUES(%d, "
+					  "            %d, "
+					  "            '%s'::TIMESTAMP WITH TIME ZONE, "
+					  "            '%s'::TIMESTAMP WITH TIME ZONE, "
+					  "            '%s', "
+					  "            '%s', "
+					  "            %llu, "
+					  "            %llu) ",
 					  get_repmgr_schema_quoted(master_conn),
-					  master_options.node, local_options.node,
-					  monitor_standby_timestamp, last_wal_standby_applied_timestamp,
-					  last_wal_master_location, last_wal_standby_received,
-					  (long long unsigned int)(lsn_master - lsn_standby_received),
-					  (long long unsigned int)(lsn_standby_received - lsn_standby_applied));
+					  master_options.node,
+					  local_options.node,
+					  monitor_standby_timestamp,
+					  last_xact_replay_timestamp,
+					  last_wal_master_location,
+					  last_xlog_receive_location,
+					  (long long unsigned int)(lsn_master_current_xlog_location - lsn_last_xlog_receive_location),
+					  (long long unsigned int)(lsn_last_xlog_receive_location - lsn_last_xlog_replay_location));
 
 	/*
 	 * Execute the query asynchronously, but don't check for a result. We will
@@ -1070,7 +1109,7 @@ do_master_failover(void)
 	XLogRecPtr	xlog_recptr;
 	bool		lsn_format_ok;
 
-	char		last_wal_standby_applied[MAXLEN];
+	char		last_xlog_replay_location[MAXLEN];
 
 	PGconn	   *node_conn = NULL;
 
@@ -1253,8 +1292,8 @@ do_master_failover(void)
 				  " considered as new master and exit.\n"),
 				PQerrorMessage(my_local_conn));
 		PQclear(res);
-		sprintf(last_wal_standby_applied, "'%X/%X'", 0, 0);
-		update_shared_memory(last_wal_standby_applied);
+		sprintf(last_xlog_replay_location, "'%X/%X'", 0, 0);
+		update_shared_memory(last_xlog_replay_location);
 		terminate(ERR_DB_QUERY);
 	}
 	/* write last location in shared memory */
@@ -1948,6 +1987,8 @@ check_node_configuration(void)
 		/* Adding the node */
 		log_info(_("adding node %d to cluster '%s'\n"),
 				 local_options.node, local_options.cluster_name);
+
+		/* XXX use create_node_record() */
 		sqlquery_snprintf(sqlquery,
 						  "INSERT INTO %s.repl_nodes"
 						  "           (id, cluster, name, conninfo, priority, witness) "
@@ -2069,7 +2110,7 @@ terminate(int retval)
 
 
 static void
-update_shared_memory(char *last_wal_standby_applied)
+update_shared_memory(char *last_xlog_replay_location)
 {
 	PGresult   *res;
 	char		sqlquery[QUERY_STR_LEN];
@@ -2077,7 +2118,7 @@ update_shared_memory(char *last_wal_standby_applied)
 	sprintf(sqlquery,
 			"SELECT %s.repmgr_update_standby_location('%s')",
 			get_repmgr_schema_quoted(my_local_conn),
-			last_wal_standby_applied);
+			last_xlog_replay_location);
 
 	/* If an error happens, just inform about that and continue */
 	res = PQexec(my_local_conn, sqlquery);

sql/repmgr3.1.1_repmgr3.1.2.sql

@@ -0,0 +1,31 @@
+/*
+ * Update a repmgr 3.1.1 installation to repmgr 3.1.2
+ * --------------------------------------------------
+ *
+ * This update is only required if repmgrd is being used in conjunction
+ * with a witness server.
+ *
+ * The new repmgr package should be installed first. Then
+ * carry out these steps:
+ *
+ *   1. (If repmgrd is used) stop any running repmgrd instances
+ *   2. On the master node, execute the SQL statement listed below
+ *   3. (If repmgrd is used) restart repmgrd
+ */
+
+/*
+ * If your repmgr installation is not included in your repmgr
+ * user's search path, please set the search path to the name
+ * of the repmgr schema to ensure objects are installed in
+ * the correct location.
+ *
+ * The repmgr schema is  "repmgr_" + the cluster name defined in
+ * 'repmgr.conf'.
+ */
+
+-- SET search_path TO 'name_of_repmgr_schema';
+
+BEGIN;
+
+ALTER TABLE repl_nodes ALTER CONSTRAINT repl_nodes_upstream_node_id_fkey DEFERRABLE;
+COMMIT;

sql/repmgr_funcs.c

@@ -83,7 +83,12 @@ _PG_init(void)
 	 * resources in repmgr_shmem_startup().
 	 */
 	RequestAddinShmemSpace(repmgr_memsize());
+
+#if (PG_VERSION_NUM >= 90600)
+	RequestNamedLWLockTranche("repmgr", 1);
+#else
 	RequestAddinLWLocks(1);
+#endif
 
 	/*
 	 * Install hooks.
@@ -128,7 +133,11 @@ repmgr_shmem_startup(void)
 	if (!found)
 	{
 		/* First time through ... */
+#if (PG_VERSION_NUM >= 90600)
+		shared_state->lock = &(GetNamedLWLockTranche("repmgr"))->lock;
+#else
 		shared_state->lock = LWLockAssign();
+#endif
 		snprintf(shared_state->location,
 				 sizeof(shared_state->location), "%X/%X", 0, 0);
 	}

strutil.h

@@ -24,12 +24,17 @@
 #include <stdlib.h>
 #include "errcode.h"
 
+
 #define QUERY_STR_LEN	8192
 #define MAXLEN			1024
 #define MAXLINELENGTH	4096
 #define MAXVERSIONSTR	16
 #define MAXCONNINFO		1024
 
+/* Why? http://stackoverflow.com/a/5459929/398670 */
+#define STR(x) CppAsString(x)
+
+#define MAXLEN_STR STR(MAXLEN)
 
 extern int
 xsnprintf(char *str, size_t size, const char *format,...)

version.h

@@ -1,6 +1,6 @@
 #ifndef _VERSION_H_
 #define _VERSION_H_
 
-#define REPMGR_VERSION "3.1.1"
+#define REPMGR_VERSION "3.2dev"
 
 #endif