Optionally don't error out due to preexisting slots in commandline utilities.

pg_receivexlog and pg_recvlogical error out when --create-slot is
specified and a slot with the same name already exists. In some cases,
especially with pg_receivexlog, that's rather annoying and requires
additional scripting.

Backpatch to 9.5 as slot control functions have newly been added to
pg_receivexlog, and there doesn't seem much point leaving it in a less
useful state.

Discussion: 20150619144755.GG29350@alap3.anarazel.de

1 files changed, 8 insertions, 1 deletions

diff --git a/src/bin/pg_basebackup/pg_recvlogical.c b/src/bin/pg_basebackup/pg_recvlogical.c
index 50844e700d9..f189f71eff6 100644
--- a/src/bin/pg_basebackup/pg_recvlogical.c
+++ b/src/bin/pg_basebackup/pg_recvlogical.c
@@ -38,6 +38,7 @@ static int	standby_message_timeout = 10 * 1000;		/* 10 sec = default */
 static int	fsync_interval = 10 * 1000; /* 10 sec = default */
 static XLogRecPtr startpos = InvalidXLogRecPtr;
 static bool do_create_slot = false;
+static bool slot_exists_ok = false;
 static bool do_start_slot = false;
 static bool do_drop_slot = false;
 
@@ -75,6 +76,7 @@ usage(void)
 	printf(_("  -f, --file=FILE        receive log into this file, - for stdout\n"));
 	printf(_("  -F  --fsync-interval=SECS\n"
 			 "                         time between fsyncs to the output file (default: %d)\n"), (fsync_interval / 1000));
+	printf(_("      --if-not-exists    do not treat naming conflicts as an error when creating a slot\n"));
 	printf(_("  -I, --startpos=LSN     where in an existing slot should the streaming start\n"));
 	printf(_("  -n, --no-loop          do not loop on connection lost\n"));
 	printf(_("  -o, --option=NAME[=VALUE]\n"
@@ -633,6 +635,7 @@ main(int argc, char **argv)
 		{"create-slot", no_argument, NULL, 1},
 		{"start", no_argument, NULL, 2},
 		{"drop-slot", no_argument, NULL, 3},
+		{"if-not-exists", no_argument, NULL, 4},
 		{NULL, 0, NULL, 0}
 	};
 	int			c;
@@ -764,6 +767,9 @@ main(int argc, char **argv)
 			case 3:
 				do_drop_slot = true;
 				break;
+			case 4:
+				slot_exists_ok = true;
+				break;
 
 			default:
 
@@ -891,8 +897,9 @@ main(int argc, char **argv)
 					progname, replication_slot);
 
 		if (!CreateReplicationSlot(conn, replication_slot, plugin,
-								   &startpos, false))
+								   false, slot_exists_ok))
 			disconnect_and_exit(1);
+		startpos = InvalidXLogRecPtr;
 	}
 
 	if (!do_start_slot)