diff --git a/dbutils.c b/dbutils.c
index 6b564959..d576bed6 100644
--- a/dbutils.c
+++ b/dbutils.c
@@ -1342,67 +1342,6 @@ get_replication_info(PGconn *conn, ReplInfo *replication_info)
}
-bool
-can_use_pg_rewind(PGconn *conn, const char *data_directory, PQExpBufferData *reason)
-{
- bool can_use = true;
-
- if (server_version_num == UNKNOWN_SERVER_VERSION_NUM)
- server_version_num = get_server_version(conn, NULL);
-
- if (server_version_num < 90500)
- {
- appendPQExpBuffer(reason,
- _("pg_rewind available from PostgreSQL 9.5"));
- return false;
- }
-
- if (guc_set(conn, "full_page_writes", "=", "off"))
- {
- if (can_use == false)
- appendPQExpBuffer(reason, "; ");
-
- appendPQExpBuffer(reason,
- _("\"full_page_writes\" must be set to \"on\""));
-
- can_use = false;
- }
-
- /*
- * "wal_log_hints" off - are data checksums available? Note: we're
- * checking the local pg_control file here as the value will be the same
- * throughout the cluster and saves a round-trip to the demotion
- * candidate.
- */
- if (guc_set(conn, "wal_log_hints", "=", "on") == false)
- {
- int data_checksum_version = get_data_checksum_version(data_directory);
-
- if (data_checksum_version < 0)
- {
- if (can_use == false)
- appendPQExpBuffer(reason, "; ");
-
- appendPQExpBuffer(reason,
- _("\"wal_log_hints\" is set to \"off\" but unable to determine data checksum version"));
- can_use = false;
- }
- else if (data_checksum_version == 0)
- {
- if (can_use == false)
- appendPQExpBuffer(reason, "; ");
-
- appendPQExpBuffer(reason,
- _("\"wal_log_hints\" is set to \"off\" and data checksums are disabled"));
-
- can_use = false;
- }
- }
-
- return can_use;
-}
-
-
int
get_ready_archive_files(PGconn *conn, const char *data_directory)
{
diff --git a/dbutils.h b/dbutils.h
index 2055637c..93fbf019 100644
--- a/dbutils.h
+++ b/dbutils.h
@@ -387,7 +387,6 @@ bool get_cluster_size(PGconn *conn, char *size);
int get_server_version(PGconn *conn, char *server_version);
RecoveryType get_recovery_type(PGconn *conn);
int get_primary_node_id(PGconn *conn);
-bool can_use_pg_rewind(PGconn *conn, const char *data_directory, PQExpBufferData *reason);
int get_ready_archive_files(PGconn *conn, const char *data_directory);
bool identify_system(PGconn *repl_conn, t_system_identification *identification);
bool repmgrd_set_local_node_id(PGconn *conn, int local_node_id);
diff --git a/doc/repmgr-standby-switchover.sgml b/doc/repmgr-standby-switchover.sgml
index bec28cce..3e1fcf41 100644
--- a/doc/repmgr-standby-switchover.sgml
+++ b/doc/repmgr-standby-switchover.sgml
@@ -84,11 +84,14 @@
-
+
Use pg_rewind to reintegrate the old primary if necessary
- (PostgreSQL 9.5 and later).
+ (and the prerequisites for using pg_rewind are met).
+ If using PostgreSQL 9.3 or 9.4, and the pg_rewind
+ binary is not installed in the PostgreSQL bin directory,
+ provide its full path. For more details see also .
diff --git a/doc/switchover.sgml b/doc/switchover.sgml
index f34c5416..74109e13 100644
--- a/doc/switchover.sgml
+++ b/doc/switchover.sgml
@@ -179,6 +179,46 @@
+
+ Switchover and pg_rewind
+
+ If the demotion candidate does not shut down smoothly or cleanly, there's a risk it
+ will have a slightly divergent timeline and will not be able to attach to the new
+ primary. To fix this situation without needing to reclone the old primary, it's
+ possible to use the pg_rewind utility, which will usually be
+ able to resync the two servers.
+
+
+ To have &repmgr; execute pg_rewind if it detects this
+ situation after promoting the new primary, add the
+ option.
+
+
+
+ If &repmgr; detects a situation where it needs to execute pg_rewind,
+ it will execute a CHECKPOINT on the new primary before executing
+ pg_rewind.
+
+
+
+ For more details on pg_rewind, see:
+ https://www.postgresql.org/docs/current/static/app-pgrewind.html.
+
+
+ pg_rewind has been part of the core PostgreSQL distribution since
+ version 9.5. Users of versions 9.3 and 9.4 will need to manually install; source code available here:
+ https://github.com/vmware/pg_rewind.
+ If the pg_rewind
+ binary is not installed in the PostgreSQL bin directory, provide
+ its full path on the demotion candidate with .
+
+
+ Note that building the 9.3/9.4 version of pg_rewind requires the PostgreSQL
+ source code. Also, PostgreSQL 9.3 does not provide wal_log_hints,
+ meaning data checksums must have been enabled when the database was initialized.
+
+
+
diff --git a/repmgr-action-node.c b/repmgr-action-node.c
index 16b50e37..1defef5e 100644
--- a/repmgr-action-node.c
+++ b/repmgr-action-node.c
@@ -1728,7 +1728,7 @@ do_node_rejoin(void)
{
log_error(_("database is not shut down cleanly"));
- if (runtime_options.force_rewind == true)
+ if (runtime_options.force_rewind_used == true)
{
log_detail(_("pg_rewind will not be able to run"));
}
@@ -1779,7 +1779,7 @@ do_node_rejoin(void)
* archived
*/
- if (runtime_options.force_rewind == true)
+ if (runtime_options.force_rewind_used == true)
{
PQExpBufferData reason;
PQExpBufferData msg;
@@ -1816,7 +1816,7 @@ do_node_rejoin(void)
* Forcibly rewind node if requested (this is mainly for use when this
* action is being executed by "repmgr standby switchover")
*/
- if (runtime_options.force_rewind == true && runtime_options.dry_run == false)
+ if (runtime_options.force_rewind_used == true && runtime_options.dry_run == false)
{
int ret;
PQExpBufferData filebuf;
@@ -1826,9 +1826,18 @@ do_node_rejoin(void)
/* execute pg_rewind */
initPQExpBuffer(&command);
- appendPQExpBuffer(&command,
- "%s -D ",
- make_pg_path("pg_rewind"));
+ if (runtime_options.force_rewind_path[0] != '\0')
+ {
+ appendPQExpBuffer(&command,
+ "%s -D ",
+ runtime_options.force_rewind_path);
+ }
+ else
+ {
+ appendPQExpBuffer(&command,
+ "%s -D ",
+ make_pg_path("pg_rewind"));
+ }
appendShellString(&command,
config_file_options.data_directory);
@@ -2438,15 +2447,15 @@ do_node_help(void)
puts("");
printf(_(" Configuration file required, runs on local node only.\n"));
puts("");
- printf(_(" --csv emit output as CSV\n"));
- printf(_(" --nagios emit output in Nagios format (individual status output only)\n"));
+ printf(_(" --csv emit output as CSV\n"));
+ printf(_(" --nagios emit output in Nagios format (individual status output only)\n"));
puts("");
printf(_(" Following options check an individual status:\n"));
- printf(_(" --archive-ready number of WAL files ready for archiving\n"));
- printf(_(" --downstream whether all downstream nodes are connected\n"));
- printf(_(" --replication-lag replication lag in seconds (standbys only)\n"));
- printf(_(" --role check node has expected role\n"));
- printf(_(" --slots check for inactive replication slots\n"));
+ printf(_(" --archive-ready number of WAL files ready for archiving\n"));
+ printf(_(" --downstream whether all downstream nodes are connected\n"));
+ printf(_(" --replication-lag replication lag in seconds (standbys only)\n"));
+ printf(_(" --role check node has expected role\n"));
+ printf(_(" --slots check for inactive replication slots\n"));
puts("");
@@ -2456,13 +2465,15 @@ do_node_help(void)
puts("");
printf(_(" Configuration file required, runs on local node only.\n"));
puts("");
- printf(_(" --dry-run check that the prerequisites are met for rejoining the node\n" \
- " (including usability of \"pg_rewind\" if requested)\n"));
- printf(_(" --force-rewind execute \"pg_rewind\" if necessary\n"));
- printf(_(" --config-files comma-separated list of configuration files to retain\n" \
- " after executing \"pg_rewind\"\n"));
- printf(_(" --config-archive-dir directory to temporarily store retained configuration files\n" \
- " (default: /tmp)\n"));
+ printf(_(" --dry-run check that the prerequisites are met for rejoining the node\n" \
+ " (including usability of \"pg_rewind\" if requested)\n"));
+ printf(_(" --force-rewind[=VALUE] execute \"pg_rewind\" if necessary\n"));
+ printf(_(" (9.3 and 9.4 - provide full \"pg_rewind\" path)\n"));
+
+ printf(_(" --config-files comma-separated list of configuration files to retain\n" \
+ " after executing \"pg_rewind\"\n"));
+ printf(_(" --config-archive-dir directory to temporarily store retained configuration files\n" \
+ " (default: /tmp)\n"));
puts("");
printf(_("NODE SERVICE\n"));
diff --git a/repmgr-action-standby.c b/repmgr-action-standby.c
index e8b50290..34b53269 100644
--- a/repmgr-action-standby.c
+++ b/repmgr-action-standby.c
@@ -2771,7 +2771,7 @@ do_standby_switchover(void)
* archived
*/
- if (runtime_options.force_rewind == true)
+ if (runtime_options.force_rewind_used == true)
{
PQExpBufferData reason;
PQExpBufferData msg;
@@ -3578,7 +3578,7 @@ do_standby_switchover(void)
* in pg_control, which is written at the first checkpoint, which might not
* occur immediately.
*/
- if (runtime_options.force_rewind == true)
+ if (runtime_options.force_rewind_used == true)
{
log_notice(_("issuing CHECKPOINT"));
checkpoint(local_conn);
@@ -3595,7 +3595,7 @@ do_standby_switchover(void)
KeyValueListCell *cell = NULL;
bool first_entry = true;
- if (runtime_options.force_rewind == false)
+ if (runtime_options.force_rewind_used == false)
{
log_error(_("new primary diverges from former primary and --force-rewind not provided"));
log_hint(_("the former primary will need to be restored manually, or use \"repmgr node rejoin\""));
@@ -3605,7 +3605,16 @@ do_standby_switchover(void)
}
appendPQExpBuffer(&node_rejoin_options,
- " --force-rewind --config-files=");
+ " --force-rewind");
+
+ if (runtime_options.force_rewind_path[0] != '\0')
+ {
+ appendPQExpBuffer(&node_rejoin_options,
+ "=%s",
+ runtime_options.force_rewind_path);
+ }
+ appendPQExpBuffer(&node_rejoin_options,
+ " --config-files=");
for (cell = remote_config_files.head; cell; cell = cell->next)
{
@@ -6315,7 +6324,9 @@ do_standby_help(void)
printf(_(" --always-promote promote standby even if behind original primary\n"));
printf(_(" --dry-run perform checks etc. but don't actually execute switchover\n"));
printf(_(" -F, --force ignore warnings and continue anyway\n"));
- printf(_(" --force-rewind 9.5 and later - use pg_rewind to reintegrate the old primary if necessary\n"));
+ printf(_(" --force-rewind[=VALUE] use \"pg_rewind\" to reintegrate the old primary if necessary\n"));
+ printf(_(" (9.3 and 9.4 - provide \"pg_rewind\" path)\n"));
+
printf(_(" -R, --remote-user=USERNAME database server username for SSH operations (default: \"%s\")\n"), runtime_options.username);
printf(_(" --siblings-follow have other standbys follow new primary\n"));
diff --git a/repmgr-client-global.h b/repmgr-client-global.h
index f8629937..8814fff5 100644
--- a/repmgr-client-global.h
+++ b/repmgr-client-global.h
@@ -92,7 +92,8 @@ typedef struct
/* "standby switchover" options */
bool always_promote;
- bool force_rewind;
+ bool force_rewind_used;
+ char force_rewind_path[MAXPGPATH];
bool siblings_follow;
/* "node status" options */
@@ -152,7 +153,7 @@ typedef struct
/* "standby register" options */ \
false, 0, DEFAULT_WAIT_START, \
/* "standby switchover" options */ \
- false, false, false, \
+ false, false, "", false, \
/* "node status" options */ \
false, \
/* "node check" options */ \
@@ -231,5 +232,6 @@ extern void get_server_action(t_server_action action, char *script, char *data_d
extern bool data_dir_required_for_action(t_server_action action);
extern void get_node_data_directory(char *data_dir_buf);
extern void init_node_record(t_node_info *node_record);
+extern bool can_use_pg_rewind(PGconn *conn, const char *data_directory, PQExpBufferData *reason);
#endif /* _REPMGR_CLIENT_GLOBAL_H_ */
diff --git a/repmgr-client.c b/repmgr-client.c
index 42e499ad..aaff7c0b 100644
--- a/repmgr-client.c
+++ b/repmgr-client.c
@@ -53,6 +53,7 @@
#include "repmgr.h"
#include "compat.h"
+#include "controldata.h"
#include "repmgr-client.h"
#include "repmgr-client-global.h"
#include "repmgr-action-primary.h"
@@ -421,7 +422,13 @@ main(int argc, char **argv)
break;
case OPT_FORCE_REWIND:
- runtime_options.force_rewind = true;
+ runtime_options.force_rewind_used = true;
+
+ if (optarg != NULL)
+ {
+ strncpy(runtime_options.force_rewind_path, optarg, MAXPGPATH);
+ }
+
break;
case OPT_SIBLINGS_FOLLOW:
@@ -1605,7 +1612,7 @@ check_cli_parameters(const int action)
}
}
- if (runtime_options.force_rewind == true)
+ if (runtime_options.force_rewind_used == true)
{
switch (action)
{
@@ -2749,3 +2756,77 @@ init_node_record(t_node_info *node_record)
create_slot_name(node_record->slot_name, config_file_options.node_id);
}
}
+
+
+bool
+can_use_pg_rewind(PGconn *conn, const char *data_directory, PQExpBufferData *reason)
+{
+ bool can_use = true;
+ int server_version_num = get_server_version(conn, NULL);
+
+ /* wal_log_hints not available in 9.3, so just determine if data checksums enabled */
+ if (server_version_num < 90400)
+ {
+ int data_checksum_version = get_data_checksum_version(data_directory);
+
+ if (data_checksum_version < 0)
+ {
+ appendPQExpBuffer(reason,
+ _("unable to determine data checksum version"));
+ can_use = false;
+ }
+ else if (data_checksum_version == 0)
+ {
+ appendPQExpBuffer(reason,
+ _("this cluster was initialised without data checksums"));
+ can_use = false;
+ }
+
+ return can_use;
+ }
+
+ /* "full_page_writes" must be on in any case */
+ if (guc_set(conn, "full_page_writes", "=", "off"))
+ {
+ if (can_use == false)
+ appendPQExpBuffer(reason, "; ");
+
+ appendPQExpBuffer(reason,
+ _("\"full_page_writes\" must be set to \"on\""));
+
+ can_use = false;
+ }
+
+ /*
+ * "wal_log_hints" off - are data checksums available? Note: we're
+ * checking the local pg_control file here as the value will be the same
+ * throughout the cluster and saves a round-trip to the demotion
+ * candidate.
+ */
+ if (guc_set(conn, "wal_log_hints", "=", "on") == false)
+ {
+ int data_checksum_version = get_data_checksum_version(data_directory);
+
+ if (data_checksum_version < 0)
+ {
+ if (can_use == false)
+ appendPQExpBuffer(reason, "; ");
+
+ appendPQExpBuffer(reason,
+ _("\"wal_log_hints\" is set to \"off\" but unable to determine data checksum version"));
+ can_use = false;
+ }
+ else if (data_checksum_version == 0)
+ {
+ if (can_use == false)
+ appendPQExpBuffer(reason, "; ");
+
+ appendPQExpBuffer(reason,
+ _("\"wal_log_hints\" is set to \"off\" and data checksums are disabled"));
+
+ can_use = false;
+ }
+ }
+
+ return can_use;
+}
diff --git a/repmgr-client.h b/repmgr-client.h
index 8ec68c69..b3ad5518 100644
--- a/repmgr-client.h
+++ b/repmgr-client.h
@@ -168,7 +168,7 @@ static struct option long_options[] =
/* "node rejoin" options */
{"config-files", required_argument, NULL, OPT_CONFIG_FILES},
{"config-archive-dir", required_argument, NULL, OPT_CONFIG_ARCHIVE_DIR},
- {"force-rewind", no_argument, NULL, OPT_FORCE_REWIND},
+ {"force-rewind", optional_argument, NULL, OPT_FORCE_REWIND},
/* "node service" options */
{"action", required_argument, NULL, OPT_ACTION},