Files
neon/test_runner/regress/test_multixact_conc.py

93 lines
2.9 KiB
Python

import random
import threading
from threading import Thread
from fixtures.log_helper import log
from fixtures.neon_fixtures import NeonEnv, check_restored_datadir_content
from fixtures.utils import query_scalar
#
# Test multixact state after branching
# Now this test is very minimalistic -
# it only checks next_multixact_id field in restored pg_control,
# since we don't have functions to check multixact internals.
#
def test_multixact_conc(neon_simple_env: NeonEnv, test_output_dir):
env = neon_simple_env
env.neon_cli.create_branch("test_multixact", "empty")
endpoint = env.endpoints.create_start("test_multixact")
log.info("postgres is running on 'test_multixact' branch")
n_records = 100
n_threads = 5
n_iters = 1000
n_restarts = 10
cur = endpoint.connect().cursor()
cur.execute(
f"""
CREATE TABLE t1(pk int primary key, val integer);
INSERT INTO t1 values (generate_series(1, {n_records}), 0);
"""
)
next_multixact_id_old = query_scalar(
cur, "SELECT next_multixact_id FROM pg_control_checkpoint()"
)
# Lock entries using parallel connections in a round-robin fashion.
def do_updates():
conn = endpoint.connect(autocommit=False)
for i in range(n_iters):
pk = random.randrange(1, n_records)
conn.cursor().execute(f"update t1 set val=val+1 where pk={pk}")
conn.cursor().execute("select * from t1 for key share")
conn.commit()
conn.close()
for iter in range(n_restarts):
threads: List[threading.Thread] = []
for i in range(n_threads):
threads.append(threading.Thread(target=do_updates, args=(), daemon=False))
threads[-1].start()
for thread in threads:
thread.join()
# Restart endpoint
endpoint.stop()
endpoint.start()
conn = endpoint.connect()
cur = conn.cursor()
cur.execute("select count(*) from t1")
assert cur.fetchone() == (n_records,)
# force wal flush
cur.execute("checkpoint")
cur.execute(
"SELECT next_multixact_id, pg_current_wal_insert_lsn() FROM pg_control_checkpoint()"
)
res = cur.fetchone()
assert res is not None
next_multixact_id = res[0]
lsn = res[1]
# Ensure that we did lock some tuples
assert int(next_multixact_id) > int(next_multixact_id_old)
# Branch at this point
env.neon_cli.create_branch("test_multixact_new", "test_multixact", ancestor_start_lsn=lsn)
endpoint_new = env.endpoints.create_start("test_multixact_new")
log.info("postgres is running on 'test_multixact_new' branch")
next_multixact_id_new = endpoint_new.safe_psql(
"SELECT next_multixact_id FROM pg_control_checkpoint()"
)[0][0]
# Check that we restored pg_controlfile correctly
assert next_multixact_id_new == next_multixact_id