Files
neon/test_runner/regress/test_lsn_mapping.py
Egor Suvorov e968b5e502 tests: do not set num_safekeepers = 1, it's the default (#2457)
Also get rid if `with_safekeepers` parameter in tests.
Its meaning has changed: `False` meant "no safekeepers" which is not
supported anymore, so we assume it's always `True`.

See #1648
2022-09-15 21:43:51 +03:00

75 lines
2.7 KiB
Python

from datetime import timedelta
from fixtures.log_helper import log
from fixtures.neon_fixtures import NeonEnvBuilder, wait_for_last_flush_lsn
from fixtures.utils import query_scalar
#
# Test pageserver get_lsn_by_timestamp API
#
def test_lsn_mapping(neon_env_builder: NeonEnvBuilder):
env = neon_env_builder.init_start()
new_timeline_id = env.neon_cli.create_branch("test_lsn_mapping")
pgmain = env.postgres.create_start("test_lsn_mapping")
log.info("postgres is running on 'test_lsn_mapping' branch")
ps_cur = env.pageserver.connect().cursor()
cur = pgmain.connect().cursor()
# Create table, and insert rows, each in a separate transaction
# Disable synchronous_commit to make this initialization go faster.
#
# Each row contains current insert LSN and the current timestamp, when
# the row was inserted.
cur.execute("SET synchronous_commit=off")
cur.execute("CREATE TABLE foo (x integer)")
tbl = []
for i in range(1000):
cur.execute(f"INSERT INTO foo VALUES({i})")
# Get the timestamp at UTC
after_timestamp = query_scalar(cur, "SELECT clock_timestamp()").replace(tzinfo=None)
tbl.append([i, after_timestamp])
# Execute one more transaction with synchronous_commit enabled, to flush
# all the previous transactions
cur.execute("INSERT INTO foo VALUES (-1)")
# Wait until WAL is received by pageserver
wait_for_last_flush_lsn(env, pgmain, env.initial_tenant, new_timeline_id)
# Check edge cases: timestamp in the future
probe_timestamp = tbl[-1][1] + timedelta(hours=1)
result = query_scalar(
ps_cur,
f"get_lsn_by_timestamp {env.initial_tenant} {new_timeline_id} '{probe_timestamp.isoformat()}Z'",
)
assert result == "future"
# timestamp too the far history
probe_timestamp = tbl[0][1] - timedelta(hours=10)
result = query_scalar(
ps_cur,
f"get_lsn_by_timestamp {env.initial_tenant} {new_timeline_id} '{probe_timestamp.isoformat()}Z'",
)
assert result == "past"
# Probe a bunch of timestamps in the valid range
for i in range(1, len(tbl), 100):
probe_timestamp = tbl[i][1]
# Call get_lsn_by_timestamp to get the LSN
lsn = query_scalar(
ps_cur,
f"get_lsn_by_timestamp {env.initial_tenant} {new_timeline_id} '{probe_timestamp.isoformat()}Z'",
)
# Launch a new read-only node at that LSN, and check that only the rows
# that were supposed to be committed at that point in time are visible.
pg_here = env.postgres.create_start(
branch_name="test_lsn_mapping", node_name="test_lsn_mapping_read", lsn=lsn
)
assert pg_here.safe_psql("SELECT max(x) FROM foo")[0][0] == i
pg_here.stop_and_destroy()