Implement SYSTEM DROP REPLICA from auxillary ZooKeeper clusters

[wzb5212]

Changelog category (leave one):

• Improvement

Changelog entry (a user-readable short description of the changes that goes to CHANGELOG.md):

Implement SYSTEM DROP REPLICA from auxillary ZooKeeper clusters, may be close #48931.

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All committers have signed the CLA.

[alesapin]

Can you please add an integration test?

[wzb5212]

Can you please add an integration test?

ok.

[wzb5212]

Can you please add an integration test?

I want to add an integration test, but find that it(tests/integration/helpers/cluster.py) doesn't support creating two sets of zookeeper clusters, Am I right?

ClickHouse/tests/integration/helpers/cluster.py

Line 2263 in 69a3823

for instance in ["zoo1", "zoo2", "zoo3"]:

I want to create two separate zookeeper clusters, as shown below, is it impossible to execute?

# zookeeper config
<clickhouse>
    <zookeeper>
        <node index="1">
            <host>zoo1</host>
            <port>2181</port>
        </node>
        <node index="2">
            <host>zoo2</host>
            <port>2181</port>
        </node>
        <node index="3">
            <host>zoo3</host>
            <port>2181</port>
        </node>
    </zookeeper>
    <auxiliary_zookeepers>
        <zookeeper2>
            <node index="1">
                <host>zoo4</host>
                <port>2181</port>
            </node>
            <node index="2">
                <host>zoo5</host>
                <port>2181</port>
            </node>
            <node index="3">
                <host>zoo6</host>
                <port>2181</port>
            </node>
        </zookeeper2>
    </auxiliary_zookeepers>
</clickhouse>

# test.py
import time

import helpers.client as client
import pytest
from helpers.cluster import ClickHouseCluster
from helpers.client import QueryRuntimeException
from helpers.test_tools import TSV

cluster = ClickHouseCluster(__file__)
node1 = cluster.add_instance(
    "node1",
    main_configs=["configs/zookeeper_config.xml", "configs/remote_servers.xml"],
    with_zookeeper=True,
    use_keeper=False,
)
node2 = cluster.add_instance(
    "node2",
    main_configs=["configs/zookeeper_config.xml", "configs/remote_servers.xml"],
    with_zookeeper=True,
    use_keeper=False,
)


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

        yield cluster

    except Exception as ex:
        print(ex)

    finally:
        cluster.shutdown()


def drop_table(nodes, table_name):
    for node in nodes:
        node.query("DROP TABLE IF EXISTS {} NO DELAY".format(table_name))


def test_drop_replica_in_auxiliary_zookeeper(started_cluster):
    drop_table([node1, node2], "test_auxiliary_zookeeper")
    for node in [node1, node2]:
        node.query(
            """
                CREATE TABLE test_auxiliary_zookeeper(a Int32)
                ENGINE = ReplicatedMergeTree('zookeeper2:/clickhouse/tables/test/test_auxiliary_zookeeper', '{replica}')
                ORDER BY a;
            """.format(
                replica=node.name
            )
        )

    # stop node2 server
    node2.stop_clickhouse()
    time.sleep(5)

    # drop replica node2
    node1.query("SYSTEM DROP REPLICA 'node2'")

    zk = cluster.get_kazoo_client("zoo4")
    assert zk.exists("/clickhouse/tables/test/test_auxiliary_zookeeper")
    assert zk.exists("/clickhouse/tables/test/test_auxiliary_zookeeper/replicas/node2") is None

[wzb5212]

@alexey-milovidov How to solve this problem?

[alexey-milovidov]

I see at least some of the integration tests have auxiliary ZooKeeper clusters, let's do something similar to make a test for this PR.

[wzb5212]

I see at least some of the integration tests have auxiliary ZooKeeper clusters, let's do something similar to make a test for this PR.

I looked at some integration tests for auxiliary ZooKeeper clusters, �such as test_reload_auxiliary_zookeepers, test_fetch_partition_from_auxiliary_zookeeper and test_replicated_merge_tree_with_auxiliary_zookeepers, but found that although they used auxiliary ZooKeeper clusters, they were actually the same set of zookeeper clusters, and I looked at the fact that tests/integration/helpers/cluster.py only created one set of zookeeper clusters.

ClickHouse/tests/integration/test_fetch_partition_from_auxiliary_zookeeper/configs/zookeeper_config.xml

Line 16 in 334b052

<auxiliary_zookeepers>

ClickHouse/tests/integration/helpers/cluster.py

Line 2246 in 334b052

for instance in ["zoo1", "zoo2", "zoo3"]:

This pr requires two separate zookeeper clusters for testing.

[wzb5212]

Can you please add an integration test?

I want to add an integration test, but find that it(tests/integration/helpers/cluster.py) doesn't support creating two sets of zookeeper clusters, Am I right?

ClickHouse/tests/integration/helpers/cluster.py

Line 2263 in 69a3823

for instance in ["zoo1", "zoo2", "zoo3"]:

I want to create two separate zookeeper clusters, as shown below, is it impossible to execute?

# zookeeper config
<clickhouse>
    <zookeeper>
        <node index="1">
            <host>zoo1</host>
            <port>2181</port>
        </node>
        <node index="2">
            <host>zoo2</host>
            <port>2181</port>
        </node>
        <node index="3">
            <host>zoo3</host>
            <port>2181</port>
        </node>
    </zookeeper>
    <auxiliary_zookeepers>
        <zookeeper2>
            <node index="1">
                <host>zoo4</host>
                <port>2181</port>
            </node>
            <node index="2">
                <host>zoo5</host>
                <port>2181</port>
            </node>
            <node index="3">
                <host>zoo6</host>
                <port>2181</port>
            </node>
        </zookeeper2>
    </auxiliary_zookeepers>
</clickhouse>

# test.py
import time

import helpers.client as client
import pytest
from helpers.cluster import ClickHouseCluster
from helpers.client import QueryRuntimeException
from helpers.test_tools import TSV

cluster = ClickHouseCluster(__file__)
node1 = cluster.add_instance(
    "node1",
    main_configs=["configs/zookeeper_config.xml", "configs/remote_servers.xml"],
    with_zookeeper=True,
    use_keeper=False,
)
node2 = cluster.add_instance(
    "node2",
    main_configs=["configs/zookeeper_config.xml", "configs/remote_servers.xml"],
    with_zookeeper=True,
    use_keeper=False,
)


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

        yield cluster

    except Exception as ex:
        print(ex)

    finally:
        cluster.shutdown()


def drop_table(nodes, table_name):
    for node in nodes:
        node.query("DROP TABLE IF EXISTS {} NO DELAY".format(table_name))


def test_drop_replica_in_auxiliary_zookeeper(started_cluster):
    drop_table([node1, node2], "test_auxiliary_zookeeper")
    for node in [node1, node2]:
        node.query(
            """
                CREATE TABLE test_auxiliary_zookeeper(a Int32)
                ENGINE = ReplicatedMergeTree('zookeeper2:/clickhouse/tables/test/test_auxiliary_zookeeper', '{replica}')
                ORDER BY a;
            """.format(
                replica=node.name
            )
        )

    # stop node2 server
    node2.stop_clickhouse()
    time.sleep(5)

    # drop replica node2
    node1.query("SYSTEM DROP REPLICA 'node2'")

    zk = cluster.get_kazoo_client("zoo4")
    assert zk.exists("/clickhouse/tables/test/test_auxiliary_zookeeper")
    assert zk.exists("/clickhouse/tables/test/test_auxiliary_zookeeper/replicas/node2") is None

@alexey-milovidov

[tavplubix]

This pr requires two separate zookeeper clusters for testing.

It does not, it's okay to do it the same way as in existing tests. See also root config parameter for zookeeper client (it allows to specify arbitrary root path)

[wzb5212]

This pr requires two separate zookeeper clusters for testing.

It does not, it's okay to do it the same way as in existing tests. See also root config parameter for zookeeper client (it allows to specify arbitrary root path)

ok, I add an integration test, please take a look.

[robot-ch-test-poll]

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