Add test for race condition

dbms/tests/queries/0_stateless/00980_alter_settings_race.reference

@@ -0,0 +1 @@
+1

dbms/tests/queries/0_stateless/00980_alter_settings_race.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+. $CURDIR/../shell_config.sh
+
+$CLICKHOUSE_CLIENT --query="DROP TABLE IF EXISTS table_for_concurrent_alter"
+
+$CLICKHOUSE_CLIENT --query="CREATE TABLE table_for_concurrent_alter (id UInt64, Data String) ENGINE = MergeTree() ORDER BY id SETTINGS index_granularity=4096;";
+
+n=0
+while [ "$n" -lt 100 ];
+do
+    n=$(( n + 1 ))
+    $CLICKHOUSE_CLIENT --query="INSERT INTO table_for_concurrent_alter VALUES(1, 'Hello')" > /dev/null 2> /dev/null &
+    $CLICKHOUSE_CLIENT --query="OPTIMIZE TABLE table_for_concurrent_alter FINAL" > /dev/null 2> /dev/null &
+done &
+
+
+q=0
+while [ "$q" -lt 100 ];
+do
+    q=$(( q + 1 ))
+    counter=$(( 100 + q ))
+    $CLICKHOUSE_CLIENT --query="ALTER TABLE table_for_concurrent_alter MODIFY SETTING parts_to_throw_insert = $counter, parts_to_delay_insert = $counter, min_merge_bytes_to_use_direct_io = $counter" > /dev/null 2> /dev/null &
+done &
+
+sleep 4
+
+# we just test race conditions, not logic
+$CLICKHOUSE_CLIENT --query "SELECT 1"
+
+$CLICKHOUSE_CLIENT --query="DROP TABLE IF EXISTS table_for_concurrent_alter"

dbms/tests/queries/0_stateless/00980_merge_alter_settings.sql

@@ -35,7 +35,7 @@ INSERT INTO table_for_alter VALUES (2, '2'); -- { serverError 252 }
 
 ALTER TABLE table_for_alter MODIFY SETTING xxx_yyy=124; -- { serverError 115 }
 
-ALTER TABLE table_for_alter MODIFY SETTING  parts_to_throw_insert = 100, parts_to_delay_insert = 100;
+ALTER TABLE table_for_alter MODIFY SETTING parts_to_throw_insert = 100, parts_to_delay_insert = 100;
 
 INSERT INTO table_for_alter VALUES (2, '2');