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#!/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_hs14.py
# Ensure that point in time reads with few visible history store records don't
# damage performance.
class test_hs14(wttest.WiredTigerTestCase):
conn_config = 'cache_size=50MB'
session_config = 'isolation=snapshot'
def test_hs14(self):
uri = 'table:test_hs14'
self.session.create(uri, 'key_format=S,value_format=S')
self.conn.set_timestamp('oldest_timestamp=' + timestamp_str(1))
cursor = self.session.open_cursor(uri)
value1 = 'a' * 500
value2 = 'b' * 500
value3 = 'c' * 500
value4 = 'd' * 500
value5 = 'e' * 500
for i in range(1, 10000):
self.session.begin_transaction()
cursor[str(i)] = value1
self.session.commit_transaction('commit_timestamp=' + timestamp_str(2))
self.session.begin_transaction()
cursor[str(i)] = value2
self.session.commit_transaction('commit_timestamp=' + timestamp_str(2))
self.session.begin_transaction()
cursor[str(i)] = value3
self.session.commit_transaction('commit_timestamp=' + timestamp_str(3))
self.session.begin_transaction()
cursor[str(i)] = value4
self.session.commit_transaction('commit_timestamp=' + timestamp_str(4))
start = time.time()
self.session.begin_transaction('read_timestamp=' + timestamp_str(3))
for i in range(1, 10000):
self.assertEqual(cursor[str(i)], value3)
self.session.rollback_transaction()
end = time.time()
# The time spent when all history store keys are visible to us.
visible_hs_latency = (end - start)
for i in range(1, 10000):
self.session.begin_transaction()
cursor.set_key(str(i))
cursor.remove()
self.session.commit_transaction('commit_timestamp=' + timestamp_str(5))
self.session.begin_transaction()
cursor[str(i)] = value5
self.session.commit_transaction('commit_timestamp=' + timestamp_str(10))
start = time.time()
self.session.begin_transaction('read_timestamp=' + timestamp_str(9))
for i in range(1, 10000):
cursor.set_key(str(i))
self.assertEqual(cursor.search(), wiredtiger.WT_NOTFOUND)
self.session.rollback_transaction()
end = time.time()
# The time spent when all history store keys are invisible to us.
invisible_hs_latency = (end - start)
self.assertLess(invisible_hs_latency, (visible_hs_latency * 10),
"Reader took an order of magnitude longer for when all "
"history store records were invisible, visible={}, invisible={}".format(
visible_hs_latency, invisible_hs_latency
))
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