Files
scylladb/alternator-test/util.py
Piotr Sarna 927dc87b9c alternator-test: bump create table time limit to 200s
Unfortunately the previous 100s limit proved to be not enough
for creating tables with both local and global indexes attached
to them. Empirically 200s was chosen as a safe default,
as the longest test oscillated around 100s with the deviation of 10s.
2019-09-11 18:01:05 +03:00

122 lines
4.8 KiB
Python

# Copyright 2019 ScyllaDB
#
# This file is part of Scylla.
#
# Scylla is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Scylla is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Scylla. If not, see <http://www.gnu.org/licenses/>.
# Various utility functions which are useful for multiple tests
import string
import random
import collections
import time
def random_string(length=10, chars=string.ascii_uppercase + string.digits):
return ''.join(random.choice(chars) for x in range(length))
def random_bytes(length=10):
return bytearray(random.getrandbits(8) for _ in range(length))
# Utility functions for scan and query into an array of items:
# TODO: add to full_scan and full_query by default ConsistentRead=True, as
# it's not useful for tests without it!
def full_scan(table, **kwargs):
response = table.scan(**kwargs)
items = response['Items']
while 'LastEvaluatedKey' in response:
response = table.scan(ExclusiveStartKey=response['LastEvaluatedKey'], **kwargs)
items.extend(response['Items'])
return items
# Utility function for fetching the entire results of a query into an array of items
def full_query(table, **kwargs):
response = table.query(**kwargs)
items = response['Items']
while 'LastEvaluatedKey' in response:
response = table.query(ExclusiveStartKey=response['LastEvaluatedKey'], **kwargs)
items.extend(response['Items'])
return items
# To compare two lists of items (each is a dict) without regard for order,
# "==" is not good enough because it will fail if the order is different.
# The following function, multiset() converts the list into a multiset
# (set with duplicates) where order doesn't matter, so the multisets can
# be compared.
def freeze(item):
if isinstance(item, dict):
return frozenset((key, freeze(value)) for key, value in item.items())
elif isinstance(item, list):
return tuple(freeze(value) for value in item)
return item
def multiset(items):
return collections.Counter([freeze(item) for item in items])
test_table_prefix = 'alternator_test_'
def test_table_name():
current_ms = int(round(time.time() * 1000))
# In the off chance that test_table_name() is called twice in the same millisecond...
if test_table_name.last_ms >= current_ms:
current_ms = test_table_name.last_ms + 1
test_table_name.last_ms = current_ms
return test_table_prefix + str(current_ms)
test_table_name.last_ms = 0
def create_test_table(dynamodb, **kwargs):
name = test_table_name()
print("fixture creating new table {}".format(name))
table = dynamodb.create_table(TableName=name,
BillingMode='PAY_PER_REQUEST', **kwargs)
waiter = table.meta.client.get_waiter('table_exists')
# recheck every second instead of the default, lower, frequency. This can
# save a few seconds on AWS with its very slow table creation, but can
# more on tests on Scylla with its faster table creation turnaround.
waiter.config.delay = 1
waiter.config.max_attempts = 200
waiter.wait(TableName=name)
return table
# DynamoDB's ListTables request returns up to a single page of table names
# (e.g., up to 100) and it is up to the caller to call it again and again
# to get the next page. This is a utility function which calls it repeatedly
# as much as necessary to get the entire list.
# We deliberately return a list and not a set, because we want the caller
# to be able to recognize bugs in ListTables which causes the same table
# to be returned twice.
def list_tables(dynamodb, limit=100):
ret = []
pos = None
while True:
if pos:
page = dynamodb.meta.client.list_tables(Limit=limit, ExclusiveStartTableName=pos);
else:
page = dynamodb.meta.client.list_tables(Limit=limit);
results = page.get('TableNames', None)
assert(results)
ret = ret + results
newpos = page.get('LastEvaluatedTableName', None)
if not newpos:
break;
# It doesn't make sense for Dynamo to tell us we need more pages, but
# not send anything in *this* page!
assert len(results) > 0
assert newpos != pos
# Note that we only checked that we got back tables, not that we got
# any new tables not already in ret. So a buggy implementation might
# still cause an endless loop getting the same tables again and again.
pos = newpos
return ret