b0d95948e1
When the mutation compactor has all the rows it needs for a page, it saves the decision to stop in a member flag: _stop. For single partition queries, the mutation compactor is kept alive across pages and so it has a method, start_new_page() to reset its state for the next page. This method didn't clear the _stop flag. This meant that the value set at the end of the previous could cause the new page and subsequently the entire query to be stopped prematurely. This can happen if the new page starts with a row that is covered by a higher level tombstone and is completely empty after compaction. Reset the _stop flag in start_new_page() to prevent this. This commit also adds a unit test which reproduces the bug. Fixes: #12361 Closes #12384
38 lines
1.4 KiB
Python
38 lines
1.4 KiB
Python
# Copyright 2020-present ScyllaDB
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#
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# SPDX-License-Identifier: AGPL-3.0-or-later
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from util import new_test_table
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from cassandra.query import SimpleStatement
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import pytest
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import nodetool
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# Test that the _stop flag set in the compactor at the end of a page is not
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# sticky and doesn't remain set on the following page. If it does it can cause
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# the next page (and consequently the entire query) to be terminated prematurely.
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# This can happen if the code path on the very first consumed fragment doesn't
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# reset this flag. Currently this is the case for rows completely covered by a
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# higher level tombstone.
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def test_sticky_stop_flag(cql, test_keyspace):
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with new_test_table(cql, test_keyspace, 'pk int, ck int, v int, PRIMARY KEY (pk, ck)') as table:
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insert_row_id = cql.prepare(f"INSERT INTO {table} (pk, ck, v) VALUES (?, ?, ?)")
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pk = 0
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# Flush the row to disk, to prevent it being compacted away in the
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# memtable upon writing the partition tombstone.
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cql.execute(insert_row_id, (pk, 100, 0))
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nodetool.flush(cql, table)
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cql.execute(f"DELETE FROM {table} WHERE pk = {pk}")
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for ck in range(0, 200):
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if ck == 100:
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continue
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cql.execute(insert_row_id, (pk, ck, 0))
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statement = SimpleStatement(f"SELECT * FROM {table} WHERE pk = {pk}", fetch_size=100)
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res = list(cql.execute(statement))
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assert len(res) == 199
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