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47bd307cb8
For better ergonomics. I always found it weird that we used UUID to actually mean a tenant or timeline ID. It worked because it happened to have the same length, 16 bytes, but it was hacky.
74 lines
2.7 KiB
Python
74 lines
2.7 KiB
Python
from datetime import timedelta
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from fixtures.log_helper import log
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from fixtures.neon_fixtures import NeonEnvBuilder
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from fixtures.utils import query_scalar
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#
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# Test pageserver get_lsn_by_timestamp API
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#
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def test_lsn_mapping(neon_env_builder: NeonEnvBuilder):
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neon_env_builder.num_safekeepers = 1
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env = neon_env_builder.init_start()
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new_timeline_id = env.neon_cli.create_branch("test_lsn_mapping")
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pgmain = env.postgres.create_start("test_lsn_mapping")
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log.info("postgres is running on 'test_lsn_mapping' branch")
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ps_cur = env.pageserver.connect().cursor()
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cur = pgmain.connect().cursor()
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# Create table, and insert rows, each in a separate transaction
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# Disable synchronous_commit to make this initialization go faster.
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#
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# Each row contains current insert LSN and the current timestamp, when
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# the row was inserted.
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cur.execute("SET synchronous_commit=off")
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cur.execute("CREATE TABLE foo (x integer)")
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tbl = []
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for i in range(1000):
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cur.execute(f"INSERT INTO foo VALUES({i})")
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# Get the timestamp at UTC
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after_timestamp = query_scalar(cur, "SELECT clock_timestamp()").replace(tzinfo=None)
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tbl.append([i, after_timestamp])
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# Execute one more transaction with synchronous_commit enabled, to flush
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# all the previous transactions
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cur.execute("SET synchronous_commit=on")
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cur.execute("INSERT INTO foo VALUES (-1)")
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# Check edge cases: timestamp in the future
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probe_timestamp = tbl[-1][1] + timedelta(hours=1)
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result = query_scalar(
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ps_cur,
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f"get_lsn_by_timestamp {env.initial_tenant} {new_timeline_id} '{probe_timestamp.isoformat()}Z'",
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)
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assert result == "future"
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# timestamp too the far history
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probe_timestamp = tbl[0][1] - timedelta(hours=10)
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result = query_scalar(
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ps_cur,
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f"get_lsn_by_timestamp {env.initial_tenant} {new_timeline_id} '{probe_timestamp.isoformat()}Z'",
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)
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assert result == "past"
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# Probe a bunch of timestamps in the valid range
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for i in range(1, len(tbl), 100):
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probe_timestamp = tbl[i][1]
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# Call get_lsn_by_timestamp to get the LSN
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lsn = query_scalar(
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ps_cur,
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f"get_lsn_by_timestamp {env.initial_tenant} {new_timeline_id} '{probe_timestamp.isoformat()}Z'",
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)
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# Launch a new read-only node at that LSN, and check that only the rows
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# that were supposed to be committed at that point in time are visible.
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pg_here = env.postgres.create_start(
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branch_name="test_lsn_mapping", node_name="test_lsn_mapping_read", lsn=lsn
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)
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assert pg_here.safe_psql("SELECT max(x) FROM foo")[0][0] == i
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pg_here.stop_and_destroy()
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