ClickHouse/tests/integration/test_temporary_data_in_cache/test.py

110 lines
3.5 KiB
Python

# pylint: disable=unused-argument
# pylint: disable=redefined-outer-name
import pytest
from helpers.cluster import ClickHouseCluster
from helpers.client import QueryRuntimeException
cluster = ClickHouseCluster(__file__)
node = cluster.add_instance(
"node",
main_configs=["configs/config.d/storage_configuration.xml"],
tmpfs=["/local_disk:size=50M", "/tiny_local_cache:size=12M"],
)
@pytest.fixture(scope="module")
def start_cluster():
try:
cluster.start()
yield cluster
finally:
cluster.shutdown()
def test_cache_evicted_by_temporary_data(start_cluster):
q = node.query
get_free_space = lambda: int(
q(
"SELECT free_space FROM system.disks WHERE name = 'tiny_local_cache_local_disk'"
).strip()
)
get_cache_size = lambda: int(
q("SELECT sum(size) FROM system.filesystem_cache").strip()
)
assert get_cache_size() == 0
assert get_free_space() > 8 * 1024 * 1024
# Codec is NONE to make cache size predictable
q(
"CREATE TABLE t1 (x UInt64 CODEC(NONE), y UInt64 CODEC(NONE)) ENGINE = MergeTree ORDER BY x SETTINGS storage_policy = 'tiny_local_cache'"
)
q("INSERT INTO t1 SELECT number, number FROM numbers(1024 * 1024)")
# To be sure that nothing is reading the cache and entries for t1 can be evited
q("OPTIMIZE TABLE t1 FINAL")
q("SYSTEM STOP MERGES t1")
# Read some data to fill the cache
q("SELECT sum(x) FROM t1")
cache_size_with_t1 = get_cache_size()
assert cache_size_with_t1 > 8 * 1024 * 1024
# Almost all disk space is occupied by t1 cache
free_space_with_t1 = get_free_space()
assert free_space_with_t1 < 4 * 1024 * 1024
# Try to sort the table, but fail because of lack of disk space
with pytest.raises(QueryRuntimeException) as exc:
q(
"SELECT ignore(*) FROM numbers(10 * 1024 * 1024) ORDER BY sipHash64(number)",
settings={
"max_bytes_before_external_group_by": "4M",
"max_bytes_before_external_sort": "4M",
},
)
assert "Failed to reserve space for the file cache" in str(exc.value)
# Some data evicted from cache by temporary data
cache_size_after_eviction = get_cache_size()
assert cache_size_after_eviction < cache_size_with_t1
# Disk space freed, at least 3 MB, because temporary data tried to write 4 MB
assert get_free_space() > free_space_with_t1 + 3 * 1024 * 1024
# Read some data to fill the cache again
q("SELECT avg(y) FROM t1")
cache_size_with_t1 = get_cache_size()
assert cache_size_with_t1 > 8 * 1024 * 1024, q(
"SELECT * FROM system.filesystem_cache FORMAT Vertical"
)
# Almost all disk space is occupied by t1 cache
free_space_with_t1 = get_free_space()
assert free_space_with_t1 < 4 * 1024 * 1024, q(
"SELECT * FROM system.disks WHERE name = 'tiny_local_cache_local_disk' FORMAT Vertical"
)
node.http_query(
"SELECT randomPrintableASCII(1024) FROM numbers(8 * 1024) FORMAT TSV",
params={"buffer_size": 0, "wait_end_of_query": 1},
)
assert get_free_space() > free_space_with_t1 + 3 * 1024 * 1024
# not enough space for buffering 32 MB
with pytest.raises(Exception) as exc:
node.http_query(
"SELECT randomPrintableASCII(1024) FROM numbers(32 * 1024) FORMAT TSV",
params={"buffer_size": 0, "wait_end_of_query": 1},
)
assert "Failed to reserve space for the file cache" in str(exc.value)
q("DROP TABLE IF EXISTS t1")