Disable warnings for remote_txn

For the tests that are using the `remote_node_set_kill_event` function
to perform a hard termination and precise stages of the 2PC the
connection will close with different warning messages depending on the
timing of connection close and SSL close.

To avoid a flaky test, this commit set `client_min_messages` to `ERROR`
for the duration of the transaction. Since checks are done after the
transaction that the transaction is properly rolled back in the event
of a crash, the warning messages does not offer any additional
benefits.

tsl/test/expected/remote_txn.out

@@ -623,8 +623,14 @@ SELECT count(*) FROM pg_prepared_xacts;
      0
 (1 row)
 
---below will fail the abort and thus ROLLBACK TRANSACTION will never be called leaving
---a prepared_xact that should be rolled back by heal server
+-- Below will fail the abort and thus ROLLBACK TRANSACTION will never
+-- be called leaving a prepared_xact that should be rolled back by
+-- heal server.
+--
+-- We set min message level to "error" since different warnings can be
+-- generated due to timing issues but check that the transaction was
+-- rolled back after the commit.
+SET client_min_messages TO error;
 BEGIN;
     SELECT remote_node_killer_set_event('pre-abort', 'loopback');
  remote_node_killer_set_event 
@@ -633,25 +639,20 @@ BEGIN;
 (1 row)
 
     SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10011,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
-NOTICE:  [loopback]:  INSERT INTO "S 1"."T 1" VALUES (10011,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') 
  remote_exec 
 -------------
 
 (1 row)
 
     SELECT test.remote_exec('{loopback2}', $$ INSERT INTO "S 1"."T 1" VALUES (10001,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
-NOTICE:  [loopback2]:  INSERT INTO "S 1"."T 1" VALUES (10001,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') 
  remote_exec 
 -------------
 
 (1 row)
 
 COMMIT;
-WARNING:  kill event: pre-abort
-WARNING:  [loopback]: terminating connection due to administrator command
-WARNING:  [loopback]: SSL connection has been closed unexpectedly
-WARNING:  failure aborting remote transaction during local abort
 ERROR:  [loopback2]: duplicate key value violates unique constraint "t1_pkey"
+RESET client_min_messages;
 SELECT count(*) FROM "S 1"."T 1" WHERE "C 1" = 10011;
  count 
 -------
@@ -734,7 +735,12 @@ SELECT count(*) FROM pg_prepared_xacts;
      0
 (1 row)
 
---test comm error in subtrans abort
+-- Test comm error in subtrans abort
+--
+-- We set min message level to "error" since different warnings can be
+-- generated due to timing issues but check that the transaction was
+-- rolled back after the commit.
+SET client_min_messages TO error;
 BEGIN;
     SELECT remote_node_killer_set_event('subxact-abort', 'loopback');
  remote_node_killer_set_event 
@@ -743,36 +749,31 @@ BEGIN;
 (1 row)
 
     SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10017,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
-NOTICE:  [loopback]:  INSERT INTO "S 1"."T 1" VALUES (10017,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') 
  remote_exec 
 -------------
 
 (1 row)
 
     SELECT test.remote_exec('{loopback2}', $$ INSERT INTO "S 1"."T 1" VALUES (10018,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
-NOTICE:  [loopback2]:  INSERT INTO "S 1"."T 1" VALUES (10018,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') 
  remote_exec 
 -------------
 
 (1 row)
 
     SAVEPOINT save_1;
         SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10001,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
-NOTICE:  [loopback]:  INSERT INTO "S 1"."T 1" VALUES (10001,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') 
  remote_exec 
 -------------
 
 (1 row)
 
     ROLLBACK TO SAVEPOINT save_1;
-WARNING:  kill event: subxact-abort
-WARNING:  [loopback]: terminating connection due to administrator command
-WARNING:  [loopback]: SSL connection has been closed unexpectedly
     SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10019,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
 ERROR:  connection to data node "loopback" was lost
     SELECT test.remote_exec('{loopback2}', $$ INSERT INTO "S 1"."T 1" VALUES (10020,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
 ERROR:  current transaction is aborted, commands ignored until end of transaction block
 COMMIT;
+RESET client_min_messages;
 SELECT count(*) FROM "S 1"."T 1" WHERE "C 1" > 10016;
  count 
 -------

tsl/test/sql/remote_txn.sql

@@ -264,13 +264,21 @@ COMMIT;
 SELECT count(*) FROM "S 1"."T 1" WHERE "C 1" = 10010;
 SELECT count(*) FROM pg_prepared_xacts;
 
---below will fail the abort and thus ROLLBACK TRANSACTION will never be called leaving
---a prepared_xact that should be rolled back by heal server
+-- Below will fail the abort and thus ROLLBACK TRANSACTION will never
+-- be called leaving a prepared_xact that should be rolled back by
+-- heal server.
+--
+-- We set min message level to "error" since different warnings can be
+-- generated due to timing issues but check that the transaction was
+-- rolled back after the commit.
+SET client_min_messages TO error;
 BEGIN;
     SELECT remote_node_killer_set_event('pre-abort', 'loopback');
     SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10011,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
     SELECT test.remote_exec('{loopback2}', $$ INSERT INTO "S 1"."T 1" VALUES (10001,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
 COMMIT;
+RESET client_min_messages;
+
 SELECT count(*) FROM "S 1"."T 1" WHERE "C 1" = 10011;
 SELECT count(*) FROM pg_prepared_xacts;
 SELECT _timescaledb_internal.remote_txn_heal_data_node((SELECT OID FROM pg_foreign_server WHERE srvname = 'loopback'));
@@ -291,7 +299,12 @@ COMMIT;
 SELECT count(*) FROM "S 1"."T 1" WHERE "C 1" > 10011;
 SELECT count(*) FROM pg_prepared_xacts;
 
---test comm error in subtrans abort
+-- Test comm error in subtrans abort
+--
+-- We set min message level to "error" since different warnings can be
+-- generated due to timing issues but check that the transaction was
+-- rolled back after the commit.
+SET client_min_messages TO error;
 BEGIN;
     SELECT remote_node_killer_set_event('subxact-abort', 'loopback');
     SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10017,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
@@ -302,6 +315,7 @@ BEGIN;
     SELECT test.remote_exec('{loopback}', $$ INSERT INTO "S 1"."T 1" VALUES (10019,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
     SELECT test.remote_exec('{loopback2}', $$ INSERT INTO "S 1"."T 1" VALUES (10020,1,'bleh', '2001-01-01', '2001-01-01', 'bleh') $$);
 COMMIT;
+RESET client_min_messages;
 
 SELECT count(*) FROM "S 1"."T 1" WHERE "C 1" > 10016;
 SELECT count(*) FROM pg_prepared_xacts;