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#!/usr/bin/env python
#
# Public Domain 2014-present 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.
from helper import copy_wiredtiger_home
import wiredtiger, wttest
from wtdataset import SimpleDataSet
from wtscenario import make_scenarios
from wiredtiger import stat
# test_prepare_hs04.py
# Read prepared updates from on-disk with ignore_prepare.
# Committing or aborting a prepared update when there exists a tombstone for that key already.
#
class test_prepare_hs04(wttest.WiredTigerTestCase):
# Force a small cache.
conn_config = 'cache_size=5MB,statistics=(fast)'
# Create a small table.
uri = "table:test_prepare_hs04"
nsessions = 3
nkeys = 40
nrows = 100
commit_values = [
('commit_transaction', dict(commit=True)),
('rollback_transaction', dict(commit=False))
]
format_values = [
# Note: commit_key must exceed nrows to give behavior comparable to the row case.
('column', dict(key_format='r', commit_key=1000, value_format='u')),
('column-fix', dict(key_format='r', commit_key=1000, value_format='8t')),
('string-row', dict(key_format='S', commit_key='C', value_format='u')),
]
scenarios = make_scenarios(commit_values, format_values)
def get_stat(self, stat):
stat_cursor = self.session.open_cursor('statistics:')
val = stat_cursor[stat][2]
stat_cursor.close()
return val
def search_keys_timestamp_and_ignore(self, ds, txn_config, expected_value, conflict=False):
cursor = self.session.open_cursor(self.uri)
commit_key = self.commit_key
self.session.begin_transaction(txn_config)
for i in range(1, self.nsessions * self.nkeys):
key = commit_key + ds.key(self.nrows + i)
cursor.set_key(key)
if conflict == True:
self.assertRaisesException(wiredtiger.WiredTigerError, lambda:cursor.search(), expected_value)
elif expected_value == None:
if self.value_format == '8t':
# In FLCS, deleted values read back as 0.
self.assertEqual(cursor.search(), 0)
self.assertEqual(cursor.get_value(), 0)
else:
self.assertEqual(cursor.search(), wiredtiger.WT_NOTFOUND)
else:
self.assertEqual(cursor.search(), 0)
self.assertEqual(cursor.get_value(), expected_value)
cursor.close()
self.session.commit_transaction()
def prepare_updates(self, ds):
commit_key = self.commit_key
if self.value_format == '8t':
commit_value = 98
prepare_value = 99
else:
commit_value = b"bbbbb" * 100
prepare_value = b"ccccc" * 100
# Set oldest and stable timestamp for the database.
self.conn.set_timestamp('oldest_timestamp=' + self.timestamp_str(1))
self.conn.set_timestamp('stable_timestamp=' + self.timestamp_str(1))
# Commit some updates to get eviction and history store fired up.
# Insert a key at timestamp 1.
cursor = self.session.open_cursor(self.uri)
for i in range(1, self.nsessions * self.nkeys):
self.session.begin_transaction()
key = commit_key + ds.key(self.nrows + i)
cursor.set_key(key)
cursor.set_value(commit_value)
self.assertEquals(cursor.insert(), 0)
self.session.commit_transaction('commit_timestamp=' + self.timestamp_str(2))
cursor.close()
# Call checkpoint.
self.session.checkpoint()
cursor = self.session.open_cursor(self.uri)
for i in range(1, self.nsessions * self.nkeys):
self.session.begin_transaction()
key = commit_key + ds.key(self.nrows + i)
cursor.set_key(key)
self.assertEquals(cursor.remove(), 0)
self.session.commit_transaction('commit_timestamp=' + self.timestamp_str(10))
cursor.close()
# Move the stable timestamp to match the timestamp for the last update.
self.conn.set_timestamp('stable_timestamp=' + self.timestamp_str(10))
hs_writes_start = self.get_stat(stat.conn.cache_write_hs)
# Have prepared updates in multiple sessions. This should ensure writing prepared updates to
# the data store. Insert the same key at timestamp 20, but with prepare updates.
sessions = [0] * self.nsessions
cursors = [0] * self.nsessions
for j in range (0, self.nsessions):
sessions[j] = self.conn.open_session()
sessions[j].begin_transaction()
cursors[j] = sessions[j].open_cursor(self.uri)
# Each session will update many consecutive keys.
start = (j * self.nkeys)
end = start + self.nkeys
for i in range(start, end):
cursors[j].set_key(commit_key + ds.key(self.nrows + i))
cursors[j].set_value(prepare_value)
self.assertEquals(cursors[j].insert(), 0)
sessions[j].prepare_transaction('prepare_timestamp=' + self.timestamp_str(20))
hs_writes = self.get_stat(stat.conn.cache_write_hs) - hs_writes_start
# Assert if not writing anything to the history store.
self.assertGreaterEqual(hs_writes, 0)
txn_config = 'read_timestamp=' + self.timestamp_str(5) + ',ignore_prepare=true'
# Search keys with timestamp 5, ignore_prepare=true and expect the cursor search to return 0 (key found)
self.search_keys_timestamp_and_ignore(ds, txn_config, commit_value)
txn_config = 'read_timestamp=' + self.timestamp_str(20) + ',ignore_prepare=true'
# Search keys with timestamp 20, ignore_prepare=true, expect the cursor to return wiredtiger.WT_NOTFOUND
self.search_keys_timestamp_and_ignore(ds, txn_config, None)
prepare_conflict_msg = '/conflict with a prepared update/'
txn_config = 'read_timestamp=' + self.timestamp_str(20) + ',ignore_prepare=false'
# Search keys with timestamp 20, ignore_prepare=false and expect the cursor the cursor search to return prepare conflict message
self.search_keys_timestamp_and_ignore(ds, txn_config, prepare_conflict_msg, True)
# If commit is True then commit the transactions and simulate a crash which would
# eventualy rollback transactions.
if self.commit == True:
# Commit the prepared_transactions with timestamp 30.
for j in range (0, self.nsessions):
sessions[j].commit_transaction(
'commit_timestamp=' + self.timestamp_str(30) + ',durable_timestamp=' + self.timestamp_str(30))
# Move the stable timestamp to match the durable timestamp for prepared updates.
self.conn.set_timestamp('stable_timestamp=' + self.timestamp_str(30))
self.session.checkpoint()
# Simulate a crash by copying to a new directory(RESTART).
copy_wiredtiger_home(self, ".", "RESTART")
# Open the new directory.
self.conn = self.setUpConnectionOpen("RESTART")
self.session = self.setUpSessionOpen(self.conn)
# After simulating a crash, search for the keys inserted. Rollback-to-stable as part of recovery
# will try restoring values according to the last known stable timestamp.
# Search keys with timestamp 5, ignore_prepare=true and expect the cursor search to return
# value committed before prepared update.
txn_config = 'read_timestamp=' + self.timestamp_str(5) + ',ignore_prepare=false'
self.search_keys_timestamp_and_ignore(ds, txn_config, commit_value)
# Search keys with timestamp 20, ignore_prepare=true and expect the cursor search to return
# WT_NOTFOUND.
txn_config = 'read_timestamp=' + self.timestamp_str(20) + ',ignore_prepare=true'
self.search_keys_timestamp_and_ignore(ds, txn_config, None)
# Search keys with timestamp 20, ignore_prepare=false and expect the cursor search to return WT_NOTFOUND.
txn_config = 'read_timestamp=' + self.timestamp_str(20) + ',ignore_prepare=false'
self.search_keys_timestamp_and_ignore(ds, txn_config, None)
# If commit is true then the commit_tramsactions was called and we will expect prepare_value.
if self.commit == True:
txn_config = 'read_timestamp=' + self.timestamp_str(30) + ',ignore_prepare=true'
# Search keys with timestamp 30, ignore_prepare=true and expect the cursor value to be prepare_value.
self.search_keys_timestamp_and_ignore(ds, txn_config, prepare_value)
else:
# Commit is false and we simulated a crash/restart which would have rolled-back the transactions, therefore we expect the
# cursor search to return WT_NOTFOUND.
txn_config = 'read_timestamp=' + self.timestamp_str(30) + ',ignore_prepare=true'
# Search keys with timestamp 30, ignore_prepare=true and expect the cursor value to return WT_NOTFOUND.
self.search_keys_timestamp_and_ignore(ds, txn_config, None)
if self.commit == True:
txn_config = 'read_timestamp=' + self.timestamp_str(30) + ',ignore_prepare=false'
# Search keys with timestamp 30, ignore_prepare=false and expect the cursor value to be prepare_value.
self.search_keys_timestamp_and_ignore(ds, txn_config, prepare_value)
else:
# Commit is false and we simulated a crash/restart which would have rolled-back the transactions, therefore we expect the
# cursor search to return WT_NOTFOUND.
txn_config = 'read_timestamp=' + self.timestamp_str(30) + ',ignore_prepare=false'
# Search keys with timestamp 30, ignore_prepare=false and expect the cursor value to return WT_NOTFOUND.
self.search_keys_timestamp_and_ignore(ds, txn_config, None)
def test_prepare_hs(self):
ds = SimpleDataSet(
self, self.uri, self.nrows, key_format=self.key_format, value_format=self.value_format)
ds.populate()
if self.value_format == '8t':
bigvalue = 97
else:
bigvalue = b"aaaaa" * 100
# Initially load huge data
cursor = self.session.open_cursor(self.uri)
for i in range(1, 10000):
cursor.set_key(ds.key(self.nrows + i))
cursor.set_value(bigvalue)
self.assertEquals(cursor.insert(), 0)
cursor.close()
self.session.checkpoint()
# We put prepared updates in multiple sessions so that we do not hang
# because of cache being full with uncommitted updates.
self.prepare_updates(ds)
if __name__ == '__main__':
wttest.run()
|
