ClickHouse/tests/integration/test_system_ddl_worker_queue/test.py

import pytest

from helpers.cluster import ClickHouseCluster

cluster = ClickHouseCluster(__file__)

node1 = cluster.add_instance('node1', main_configs=['configs/remote_servers.xml'], with_zookeeper=True)
node2 = cluster.add_instance('node2', main_configs=['configs/remote_servers.xml'], with_zookeeper=True)
node3 = cluster.add_instance('node3', main_configs=['configs/remote_servers.xml'], with_zookeeper=True)
node4 = cluster.add_instance('node4', main_configs=['configs/remote_servers.xml'], with_zookeeper=True)

nodes = [node1, node2, node3, node4]


@pytest.fixture(scope="module")
def started_cluster():
    try:
        cluster.start()

        for i, node in enumerate([node1, node2]):
            node.query("CREATE DATABASE testdb")
            node.query(
                '''CREATE TABLE testdb.test_table(id UInt32, val String) ENGINE = ReplicatedMergeTree('/clickhouse/test/test_table1', '{}') ORDER BY id;'''.format(
                    i))
        for i, node in enumerate([node3, node4]):
            node.query("CREATE DATABASE testdb")
            node.query(
                '''CREATE TABLE testdb.test_table(id UInt32, val String) ENGINE = ReplicatedMergeTree('/clickhouse/test/test_table2', '{}') ORDER BY id;'''.format(
                    i))
        yield cluster

    finally:
        cluster.shutdown()


def test_distributed_ddl_queue(started_cluster):
    node1.query("INSERT INTO testdb.test_table SELECT number, toString(number) FROM numbers(100)")
    node3.query("INSERT INTO testdb.test_table SELECT number, toString(number) FROM numbers(100)")
    node2.query("SYSTEM SYNC REPLICA testdb.test_table")
    node4.query("SYSTEM SYNC REPLICA testdb.test_table")

    node1.query("ALTER TABLE testdb.test_table ON CLUSTER test_cluster ADD COLUMN somecolumn UInt8 AFTER val",
                settings={"replication_alter_partitions_sync": "2"})
    for node in nodes:
        node.query("SYSTEM SYNC REPLICA testdb.test_table")
        assert node.query("SELECT somecolumn FROM testdb.test_table LIMIT 1") == "0\n"
        assert node.query(
            "SELECT If((SELECT count(*) FROM system.distributed_ddl_queue  WHERE cluster='test_cluster' AND entry='query-0000000000') > 0, 'ok', 'fail')") == "ok\n"