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#!/usr/bin/env python
#
# Public Domain 2014-2019 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 wiredtiger import stat
from wtdataset import SimpleDataSet
def timestamp_str(t):
return '%x' % t
# test_las03.py
# Ensure checkpoints don't read too unnecessary lookaside entries.
class test_las03(wttest.WiredTigerTestCase):
# Force a small cache.
def conn_config(self):
return 'cache_size=50MB,statistics=(fast)'
def get_stat(self, stat):
stat_cursor = self.session.open_cursor('statistics:')
val = stat_cursor[stat][2]
stat_cursor.close()
return val
def large_updates(self, session, uri, value, ds, nrows, nops):
# Update a large number of records, we'll hang if the lookaside table
# isn't doing its thing.
cursor = session.open_cursor(uri)
for i in range(nrows + 1, nrows + nops + 1):
session.begin_transaction()
cursor[ds.key(i)] = value
session.commit_transaction('commit_timestamp=' + timestamp_str(i))
cursor.close()
def test_checkpoint_las_reads(self):
# Create a small table.
uri = "table:test_las03"
nrows = 100
ds = SimpleDataSet(self, uri, nrows, key_format="S", value_format='u')
ds.populate()
bigvalue = "aaaaa" * 100
# Initially load huge data
cursor = self.session.open_cursor(uri)
for i in range(1, 10000):
cursor[ds.key(nrows + i)] = bigvalue
cursor.close()
self.session.checkpoint()
# Check to see LAS working with old timestamp
bigvalue2 = "ddddd" * 100
self.conn.set_timestamp('stable_timestamp=' + timestamp_str(1))
las_writes_start = self.get_stat(stat.conn.cache_write_lookaside)
self.large_updates(self.session, uri, bigvalue2, ds, nrows, 10000)
# If the test sizing is correct, the history will overflow the cache
self.session.checkpoint()
las_writes = self.get_stat(stat.conn.cache_write_lookaside) - las_writes_start
self.assertGreaterEqual(las_writes, 0)
for ts in range(2, 4):
self.conn.set_timestamp('stable_timestamp=' + timestamp_str(ts))
# Now just update one record and checkpoint again
self.large_updates(self.session, uri, bigvalue2, ds, nrows, 1)
las_reads_start = self.get_stat(stat.conn.cache_read_lookaside)
self.session.checkpoint()
las_reads = self.get_stat(stat.conn.cache_read_lookaside) - las_reads_start
# Since we're dealing with eviction concurrent with checkpoints
# and skewing is controlled by a heuristic, we can't put too tight
# a bound on this.
self.assertLessEqual(las_reads, 100)
if __name__ == '__main__':
wttest.run()
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