Add test for user exception check

dbms/tests/integration/test_concurrent_queries_for_user_restriction/configs/remote_servers.xml

@@ -0,0 +1,16 @@
+<yandex>
+    <remote_servers>
+        <test_cluster>
+            <shard>
+                <replica>
+                    <host>node1</host>
+                    <port>9000</port>
+                </replica>
+                <replica>
+                    <host>node2</host>
+                    <port>9000</port>
+                </replica>
+            </shard>
+        </test_cluster>
+    </remote_servers>
+</yandex>

dbms/tests/integration/test_concurrent_queries_for_user_restriction/configs/user_restrictions.xml

@@ -0,0 +1,38 @@
+<yandex>
+    <profiles>
+        <default>
+            <max_memory_usage>10000000000</max_memory_usage>
+            <use_uncompressed_cache>0</use_uncompressed_cache>
+            <load_balancing>random</load_balancing>
+        </default>
+        <good>
+            <max_memory_usage>10000000000</max_memory_usage>
+            <use_uncompressed_cache>0</use_uncompressed_cache>
+            <load_balancing>random</load_balancing>
+            <max_concurrent_queries_for_user>2</max_concurrent_queries_for_user>
+        </good>
+    </profiles>
+    <users>
+        <default>
+            <password></password>
+            <networks incl="networks" replace="replace">
+                <ip>::/0</ip>
+            </networks>
+            <profile>default</profile>
+            <quota>default</quota>
+        </default>
+        <good>
+            <password></password>
+            <networks incl="networks" replace="replace">
+                <ip>::/0</ip>
+            </networks>
+            <profile>good</profile>
+            <quota>default</quota>
+        </good>
+    </users>
+
+    <quotas>
+        <default>
+        </default>
+    </quotas>
+</yandex>

dbms/tests/integration/test_concurrent_queries_for_user_restriction/test.py

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+import time
+
+import pytest
+
+from multiprocessing.dummy import Pool
+from helpers.cluster import ClickHouseCluster
+
+cluster = ClickHouseCluster(__file__)
+
+node1 = cluster.add_instance('node1', user_configs=['configs/user_restrictions.xml'], main_configs=['configs/remote_servers.xml'])
+node2 = cluster.add_instance('node2', user_configs=['configs/user_restrictions.xml'], main_configs=['configs/remote_servers.xml'])
+
+@pytest.fixture(scope="module")
+def started_cluster():
+    try:
+        cluster.start()
+        for num, node in enumerate([node1, node2]):
+            node.query("create table real_tbl (ID UInt64, Value String) ENGINE = MergeTree() order by tuple()")
+            node.query("insert into real_tbl values(0, '0000'), (1, '1111')")
+            node.query("create table distr_tbl (ID UInt64, Value String) ENGINE Distributed(test_cluster, default, real_tbl)")
+
+        node1.query("create table nums (number UInt64) ENGINE = MergeTree() order by tuple()")
+        node1.query("insert into nums values(0),(1)")
+
+        yield cluster
+    finally:
+        cluster.shutdown()
+
+def num_getter(num):
+    if num % 2 == 0:
+        return node1
+    else:
+        return node2
+
+@pytest.mark.parametrize("node_getter", [
+    (lambda _: node1),
+    (lambda _: node2),
+    (num_getter),
+])
+def test_exception_message(started_cluster, node_getter):
+    assert node1.query("select ID from distr_tbl order by ID") == "0\n1\n"
+    assert node1.query("select number from nums order by number") == "0\n1\n"
+    try:
+        p = Pool(10)
+        def query(num):
+            node = node_getter(num)
+            node.query(
+                    "select sleep(2) from distr_tbl where ID GLOBAL IN (select number from remote('node1', 'default', 'nums'))",
+                    user='good')
+
+        p.map(query, xrange(3))
+    except Exception as ex:
+        assert 'Too many simultaneous queries for user good.' in ex.message
+        print ex.message