Document upgrade process from repmgr3

Also provide unpackaged extension upgrade SQL, and a script to
assist converting repmgr.conf files.

README.md

@@ -26,14 +26,6 @@ objects used by repmgr are stored in a dedicated `repmgr` schema, rather
 than `repmgr_$cluster_name`. Note there is no need to install the extension,
 this will be done automatically by `repmgr primary register`.
 
-Metadata tables have been revised and are not backwards-compatible with repmgr 3.x,
-however future DDL updates will be easier as they can be carried out via the
-`ALTER EXTENSION` mechanism.
-
-An extension upgrade script will be provided for pre-4.0 installations;
-note this will require the existing `repmgr_$cluster_name` schema to
-be renamed to `repmgr` beforehand.
-
 Some configuration items have had their names changed for consistency
 and clarity e.g. `node` => `node_id`. `repmgr` will issue a warning
 about deprecated/altered options.
@@ -44,6 +36,12 @@ upstream ID, which might change over time.
 
 See file `doc/changes-in-repmgr4.md` for more details.
 
+To upgrade from repmgr 3.x, both the `repmgr` metadatabase and all
+repmgr configuration files need to be converted. This is quite
+straightforward and scripts are provided to assist with this.
+See document `docs/upgrading-from-repmgr3.md` for further details.
+
+
 Overview
 --------
 
@@ -148,6 +146,9 @@ UNIX-like system supported by PostgreSQL itself.
 `repmgr 4` supports PostgreSQL from version 9.5. If you need to using `repmgr`
 on earlier versions of PostgreSQL 9.3 or 9.4, please use `repmgr 3.3`.
 
+If upgrading from `repmgr 3`, please see the separate upgrade guide
+`docs/upgrading-from-repmgr3.md`.
+
 All servers in the replication cluster must be running the same major version of
 PostgreSQL, and we recommend that they also run the same minor version.
 

configfile.c

@@ -528,7 +528,7 @@ _parse_config(t_configuration_options *options, ItemList *error_list, ItemList *
 							 _("parameter \"master_reponse_timeout\" has been removed; use \"async_query_timeout\" instead"));
 			known_parameter = false;
 		}
-		else if (strcmp(name, "master_reponse_timeout") == 0)
+		else if (strcmp(name, "retry_promote_interval_secs") == 0)
 		{
 			item_list_append(warning_list,
 							 _("parameter \"retry_promote_interval_secs\" has been removed; use \"primary_notification_timeout\" instead"));

contrib/convert-config.pl

@@ -0,0 +1,88 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+
+if (scalar @ARGV < 1) {
+    print qq|Please provide path to the repmgr.conf file as first parameter\n|;
+    exit(1);
+}
+
+my $file = $ARGV[0];
+
+if (!-e $file) {
+    print qq|Provide file "$file" does not exist\n|;
+    exit(1);
+}
+
+if (!-f $file) {
+    print qq|Provide path "$file" does not point to a file\n|;
+    exit(1);
+}
+
+my @outp = ();
+my $fh = undef;
+
+if (!open ($fh, $file)){
+    print qq|Unable to open "$file"\n|;
+    exit(1);
+}
+
+my $data_directory_found = 0;
+
+while(<$fh>) {
+    my $line = $_;
+    chomp $line;
+    if ($line =~ m|\s*#|) {
+        push @outp, $line;
+        continue;
+    }
+
+    if ($line !~ m|\s*(\S+?)\s*=(.+?)$|) {
+        push @outp, $line;
+        continue;
+    }
+
+    my $param = $1;
+    my $value = $2;
+
+    # These parameters can be removed:
+    next if ($param eq 'cluster');
+
+    # These parameters can be renamed:
+    if ($param eq 'node') {
+        push @outp, qq|node_id=${value}|;
+    }
+    elsif ($param eq 'failover') {
+        push @outp, qq|failover_mode=${value}|;
+    }
+    elsif ($param eq 'loglevel') {
+        push @outp, qq|log_level=${value}|;
+    }
+    elsif ($param eq 'logfacility') {
+        push @outp, qq|log_facility=${value}|;
+    }
+    elsif ($param eq 'logfile') {
+        push @outp, qq|log_file=${value}|;
+    }
+    elsif ($param eq 'master_reponse_timeout') {
+        push @outp, qq|async_query_timeout=${value}|;
+    }
+    else {
+        if ($param eq 'data_directory') {
+            $data_directory_found = 1;
+        }
+        push @outp, $line;
+    }
+}
+
+close $fh;
+
+print join("\n", @outp);
+print "\n";
+
+if ($data_directory_found == 0) {
+    print "data_directory=\n";
+}
+

doc/upgrading-from-repmgr3.md

@@ -0,0 +1,122 @@
+Upgrading from repmgr 3
+=======================
+
+The upgrade process consists of two steps:
+
+    1) converting the repmgr.conf configuration files
+    2) upgrading the repmgr schema.
+
+Scripts are provided to assist both with converting repmgr.conf
+and upgrading the schema.
+
+Converting repmgr.conf configuration files
+------------------------------------------
+
+With a completely new repmgr version, we've taken the opportunity
+to rename some configuration items have had their names changed for
+clarity and consistency, both between the configuration file and
+the column names in `repmgr.nodes` (e.g. `node` → `node_id`), and
+also for consistency with PostgreSQL naming conventions
+(e.g. `loglevel` → `log_level`).
+
+Other configuration items have been changed to command line options,
+and vice-versa, e.g. to avoid hard-coding items such as a a node's
+upstream ID, which might change oer time.
+
+`repmgr` will issue a warning about deprecated/altered options.
+
+
+### Changed parameters
+
+Following parameters have been added:
+
+    - `data_directory`: this is mandatory and must contain the path
+        to the node's data directory
+    - `monitoring_history`: this replaces the `repmgrd` command line
+        option `--monitoring-history`
+
+Following parameters have been renamed:
+
+    - `failover` → `failover_mode`
+    - `node` → `node_id`
+    - `loglevel` → `log_level`
+    - `logfacility` → `log_facility`
+    - `logfile` → `log_file`
+    - `master_reponse_timeout` → `async_query_timeout`
+
+Following parameters have been removed:
+
+    - `cluster` is no longer required and will be ignored.
+    - `upstream_node_id` is replaced by the command-line parameter
+         `--upstream-node-id`
+
+### Conversion script
+
+To assist with conversion of `repmgr.conf` files, a Perl script
+is provided in `contrib/convert-config.pl`. Use like this:
+
+    $ ./convert-config.pl /etc/repmgr.conf
+    node_id=2
+    node_name=node2
+    conninfo=host=localhost dbname=repmgr user=repmgr port=5602
+    pg_ctl_options='-l /tmp/postgres.5602.log'
+    pg_bindir=/home/barwick/devel/builds/HEAD/bin
+    rsync_options=--exclude=postgresql.local.conf --archive
+    log_level=DEBUG
+    pg_basebackup_options=--no-slot
+    data_directory=
+
+The converted file is printed to `STDOUT` and the original file is not
+changed.
+
+Please note that the parameter `data_directory` *must* be provided;
+if not already present, the conversion script will add an empty
+placeholder parameter.
+
+
+Upgrading the repmgr schema
+---------------------------
+
+Ensure `repmgrd` is not running, or any cronjobs which execute the
+`repmgr` binary.
+
+Install `repmgr4`; any `repmgr3` packages should be uninstalled
+(if not automatically installed already).
+
+### Manually create the repmgr extension
+
+In the database used by the existing `repmgr` configuration, execute:
+
+    CREATE EXTENSION repmgr FROM unpackaged;
+
+This will move and convert all objects from the existing schema
+into the new, standard `repmgr` schema.
+
+> *NOTE* there must be only one schema matching 'repmgr_%' in the
+> database, otherwise this step may not work.
+
+### Re-register each node
+
+This is necessary to update the `repmgr` metadata with some additional items.
+
+On the primary node, execute e.g.
+
+    repmgr primary register -f /etc/repmgr.conf --force
+
+On each standby node, execute e.g.
+
+    repmgr standby register -f /etc/repmgr.conf --force
+
+Check the data is updated as expected by examining the `repmgr.nodes` table;
+restart `repmgrd` if required.
+
+The original `repmgr_$cluster` schema can be dropped at any time.
+
+* * *
+
+> *TIP* If you don't care about any data from the existing `repmgr` installation,
+> (e.g. the contents of the `events` and `monitoring` tables), the manual
+> "CREATE EXTENSION" step can be skipped; just re-register each node, starting
+> with the primary node, and the `repmgr` extension will be automatically created.
+
+* * *

repmgr--unpackaged--4.0.sql

@@ -1,5 +1,5 @@
 -- complain if script is sourced in psql, rather than via CREATE EXTENSION
--- \echo Use "CREATE EXTENSION repmgr" to load this file. \quit
+\echo Use "CREATE EXTENSION repmgr" to load this file. \quit
 
 -- extract the current schema name
 -- NOTE: this assumes there will be only one schema matching 'repmgr_%';
@@ -12,18 +12,24 @@ SELECT nspname AS old_schema
  WHERE nspname LIKE 'repmgr_%'
  LIMIT 1;
 
-DO $$
+-- move old objects into new schema
+DO $repmgr$
 DECLARE
-  old_schema TEXT;
+  schema TEXT;
 BEGIN
-  old_schema := SELECT old_schema FROM repmgr_old_schema;
-  ALTER SCHEMA  RENAME TO repmgr;
-END$$;
+  SELECT old_schema FROM repmgr_old_schema
+    INTO schema;
+  EXECUTE format('ALTER TABLE %I.repl_nodes SET SCHEMA repmgr', schema);
+  EXECUTE format('ALTER TABLE %I.repl_events SET SCHEMA repmgr', schema);
+  EXECUTE format('ALTER TABLE %I.repl_monitor SET SCHEMA repmgr', schema);
+  EXECUTE format('ALTER VIEW %I.repl_show_nodes SET SCHEMA repmgr', schema);
+  EXECUTE format('ALTER VIEW %I.repl_status SET SCHEMA repmgr', schema);
+END$repmgr$;
 
 -- convert "repmgr_$cluster.repl_nodes" to "repmgr.nodes"
 CREATE TABLE nodes (
   node_id          INTEGER     PRIMARY KEY,
-  upstream_node_id INTEGER     NULL REFERENCES nodes (node_id) DEFERRABLE,
+  upstream_node_id INTEGER     NULL REFERENCES repmgr.nodes (node_id) DEFERRABLE,
   active           BOOLEAN     NOT NULL DEFAULT TRUE,
   node_name        TEXT        NOT NULL,
   type             TEXT        NOT NULL CHECK (type IN('primary','standby','bdr')),
@@ -44,11 +50,11 @@ SELECT id, upstream_node_id, active, name,
  ORDER BY id;
 
 
--- convert "repmgr_$cluster.repl_event" to "repmgr.event"
+-- convert "repmgr_$cluster.repl_event" to "event"
 
-ALTER TABLE repl_events RENAME TO event;
+ALTER TABLE repl_events RENAME TO events;
 
--- convert "repmgr_$cluster.repl_monitor" to "repmgr.monitor"
+-- convert "repmgr_$cluster.repl_monitor" to "monitor"
 
 ALTER TABLE repl_monitor RENAME TO monitor;
 
@@ -125,3 +131,5 @@ CREATE FUNCTION unset_bdr_failover_handler()
   AS '$libdir/repmgr', 'unset_bdr_failover_handler'
   LANGUAGE C STRICT;
 
+-- remove temporary table
+DROP TABLE repmgr_old_schema;

repmgr-action-standby.c

@@ -571,6 +571,7 @@ check_barman_config(void)
  * Event(s):
  *  - standby_register
  */
+// XXX check --upstream-node-id works when re-registering
 
 void
 do_standby_register(void)

repmgr-client.c

@@ -3034,11 +3034,16 @@ init_node_record(t_node_info *node_record)
 	node_record->priority = config_file_options.priority;
 	node_record->active = true;
 
-	strncpy(node_record->location, config_file_options.location, MAXLEN);
+
+	if (config_file_options.location[0] != '\0')
+		strncpy(node_record->location, config_file_options.location, MAXLEN);
+	else
+		strncpy(node_record->location, "default", MAXLEN);
+
 
 	strncpy(node_record->node_name, config_file_options.node_name, MAXLEN);
 	strncpy(node_record->conninfo, config_file_options.conninfo, MAXLEN);
-	strncpy(node_record->config_file, config_file_path, MAXLEN);
+	strncpy(node_record->config_file, config_file_path, MAXPGPATH);
 
 	if (config_file_options.replication_user[0] != '\0')
 	{
@@ -3048,11 +3053,16 @@ init_node_record(t_node_info *node_record)
 	else
 	{
 		/* use the "user" value from "conninfo" */
-		(void)get_conninfo_value(config_file_options.conninfo, "user", node_record->repluser);
+		char repluser[MAXLEN] = "";
+
+		(void)get_conninfo_value(config_file_options.conninfo, "user", repluser);
+		strncpy(node_record->repluser, repluser, NAMEDATALEN);
 	}
 
 	if (config_file_options.use_replication_slots == true)
 	{
 		maxlen_snprintf(node_record->slot_name, "repmgr_slot_%i", config_file_options.node_id);
 	}
+
+
 }