import pytest import time from helpers.cluster import ClickHouseCluster from helpers.test_tools import assert_eq_with_retry cluster = ClickHouseCluster(__file__) node1 = cluster.add_instance('node1', with_zookeeper=True) node2 = cluster.add_instance('node2', with_zookeeper=True) @pytest.fixture(scope="module") def started_cluster(): try: cluster.start() yield cluster finally: cluster.shutdown() def test_replica_always_download(started_cluster): node1.query(""" CREATE TABLE test_table( key UInt64, value String ) ENGINE = ReplicatedMergeTree('/clickhouse/tables/test_table/replicated', '1') ORDER BY tuple() """) node2.query(""" CREATE TABLE test_table( key UInt64, value String ) ENGINE = ReplicatedMergeTree('/clickhouse/tables/test_table/replicated', '2') ORDER BY tuple() SETTINGS always_fetch_merged_part=1 """) # Stop merges on single node node1.query("SYSTEM STOP MERGES") for i in range(0, 10): node1.query("INSERT INTO test_table VALUES ({}, '{}')".format(i, i)) assert node1.query("SELECT COUNT() FROM test_table") == "10\n" assert_eq_with_retry(node2, "SELECT COUNT() FROM test_table", "10\n") time.sleep(3) # Nothing is merged assert node1.query("SELECT COUNT() FROM system.parts WHERE table = 'test_table' and active=1") == "10\n" assert node2.query("SELECT COUNT() FROM system.parts WHERE table = 'test_table' and active=1") == "10\n" node1.query("SYSTEM START MERGES") time.sleep(3) node1_parts = node1.query("SELECT COUNT() FROM system.parts WHERE table = 'test_table' and active=1").strip() node2_parts = node2.query("SELECT COUNT() FROM system.parts WHERE table = 'test_table' and active=1").strip() assert int(node1_parts) < 10 # something merged assert int(node2_parts) < 10