#!/usr/bin/env python # # Public Domain 2014-2020 MongoDB, Inc. # Public Domain 2008-2014 WiredTiger, Inc. # # This is free and unencumbered software released into the public domain. # # Anyone is free to copy, modify, publish, use, compile, sell, or # distribute this software, either in source code form or as a compiled # binary, for any purpose, commercial or non-commercial, and by any # means. # # In jurisdictions that recognize copyright laws, the author or authors # of this software dedicate any and all copyright interest in the # software to the public domain. We make this dedication for the benefit # of the public at large and to the detriment of our heirs and # successors. We intend this dedication to be an overt act of # relinquishment in perpetuity of all present and future rights to this # software under copyright law. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. # IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR # OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, # ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR # OTHER DEALINGS IN THE SOFTWARE. import time, wiredtiger, wttest def timestamp_str(t): return '%x' % t # test_hs19.py # Ensure eviction doesn't clear the history store again after checkpoint has done so because of the same update without timestamp. class test_hs19(wttest.WiredTigerTestCase): conn_config = 'cache_size=5MB,eviction=(threads_max=1)' session_config = 'isolation=snapshot' def test_hs19(self): uri = 'table:test_hs19' junk_uri = 'table:junk' self.session.create(uri, 'key_format=S,value_format=S') session2 = self.conn.open_session() session2.create(junk_uri, 'key_format=S,value_format=S') cursor2 = session2.open_cursor(junk_uri) cursor = self.session.open_cursor(uri) self.conn.set_timestamp( 'oldest_timestamp=' + timestamp_str(1) + ',stable_timestamp=' + timestamp_str(1)) value1 = 'a' * 500 value2 = 'b' * 500 value3 = 'c' * 50000 # Insert an update without timestamp. self.session.begin_transaction() cursor[str(0)] = value1 self.session.commit_transaction() # Do 2 modifies. self.session.begin_transaction() cursor.set_key(str(0)) mods = [wiredtiger.Modify('B', 100, 1)] self.assertEqual(cursor.modify(mods), 0) self.session.commit_transaction('commit_timestamp=' + timestamp_str(1)) self.session.begin_transaction() cursor.set_key(str(0)) mods = [wiredtiger.Modify('C', 101, 1)] self.assertEqual(cursor.modify(mods), 0) self.session.commit_transaction('commit_timestamp=' + timestamp_str(2)) # Start a transaction to pin back the reconciliation last running value. session2.begin_transaction() cursor2[str(1)] = value3 # Insert a modify ahead of our reconstructed modify, this one will be used unintentionally # to reconstruct the final value, corrupting the resulting value. # The 0 at the end of the modify call indicates how many bytes to replace, we keep # it as 0 here to not overwrite any of the existing value. self.session.begin_transaction() cursor.set_key(str(0)) mods = [wiredtiger.Modify('AAAAAAAAAA', 102, 0)] self.assertEqual(cursor.modify(mods), 0) self.session.commit_transaction('commit_timestamp=' + timestamp_str(3)) # Insert a modify to get written as the on disk value by checkpoint. self.session.begin_transaction() cursor.set_key(str(0)) mods = [wiredtiger.Modify('D', 102, 1)] self.assertEqual(cursor.modify(mods), 0) self.session.commit_transaction('commit_timestamp=' + timestamp_str(4)) # Checkpoint such that all modifies get written out to the history store and the latest # modify gets written to the on disk value. self.session.checkpoint('use_timestamp=true') # Add an additional modify so that when eviction sees this page it will rewrite it as it's # dirty. self.session.begin_transaction() cursor.set_key(str(0)) mods = [wiredtiger.Modify('E', 103, 1)] self.assertEqual(cursor.modify(mods), 0) self.session.commit_transaction('commit_timestamp=' + timestamp_str(5)) # First deposition the first cursor, so the page can be evicted. cursor.reset() evict_cursor = self.session.open_cursor(uri, None, "debug=(release_evict)") # Search for the key so we position our cursor on the page that we want to evict. evict_cursor.set_key(str(0)) evict_cursor.search() evict_cursor.reset() evict_cursor.close() # Construct and test the value as at timestamp 1 expected = list(value1) expected[100] = 'B' expected = str().join(expected) # Retrieve the value at timestamp 1. self.session.begin_transaction('read_timestamp=' + timestamp_str(1)) cursor.set_key(str(0)) cursor.search() # Assert that it matches our expected value. self.assertEqual(cursor.get_value(), expected) self.session.rollback_transaction() # Construct and test the value as at timestamp 2 expected = list(expected) expected[101] = 'C' expected = str().join(expected) # Retrieve the value at timestamp 1. self.session.begin_transaction('read_timestamp=' + timestamp_str(2)) cursor.set_key(str(0)) cursor.search() # Assert that it matches our expected value. self.assertEqual(cursor.get_value(), expected) self.session.rollback_transaction() # Construct and test the value as at timestamp 3 expected = list(expected) for x in range(10): expected[102 + x] = 'A' expected.append('a') expected = str().join(expected) # Retrieve the value at timestamp 1. self.session.begin_transaction('read_timestamp=' + timestamp_str(3)) cursor.set_key(str(0)) cursor.search() # Assert that it matches our expected value. self.assertEqual(cursor.get_value(), expected) self.session.rollback_transaction()