swift/test/unit/cli/test_ring_builder_analyzer.py
Samuel Merritt ccf0758ef1 Add ring-builder analyzer.
This is a tool to help developers quantify changes to the ring
builder. It takes a scenario (JSON file) describing the builder's
basic parameters (part_power, replicas, etc.) and a number of
"rounds", where each round is a set of operations to perform on the
builder. For each round, the operations are applied, and then the
builder is rebalanced until it reaches a steady state.

The idea is that a developer observes the ring builder behaving
suboptimally, writes a scenario to reproduce the behavior, modifies
the ring builder to fix it, and references the scenario with the
commit so that others can see that things have improved.

I decided to write this after writing my fourth or fifth hacky one-off
script to reproduce some bad behavior in the ring builder.

Change-Id: I114242748368f142304aab90a6d99c1337bced4c
2015-07-02 08:16:03 -07:00

228 lines
8.7 KiB
Python

#! /usr/bin/env python
# Copyright (c) 2015 Samuel Merritt <sam@swiftstack.com>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
# implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import json
import mock
import unittest
from StringIO import StringIO
from swift.cli.ring_builder_analyzer import parse_scenario, run_scenario
class TestRunScenario(unittest.TestCase):
def test_it_runs(self):
scenario = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0,
'rounds': [[['add', 'r1z2-3.4.5.6:7/sda8', 100],
['add', 'z2-3.4.5.6:7/sda9', 200]],
[['set_weight', 0, 150]],
[['remove', 1]]]}
parsed = parse_scenario(json.dumps(scenario))
fake_stdout = StringIO()
with mock.patch('sys.stdout', fake_stdout):
run_scenario(parsed)
# Just test that it produced some output as it ran; the fact that
# this doesn't crash and produces output that resembles something
# useful is good enough.
self.assertTrue('Rebalance' in fake_stdout.getvalue())
class TestParseScenario(unittest.TestCase):
def test_good(self):
scenario = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0,
'rounds': [[['add', 'r1z2-3.4.5.6:7/sda8', 100],
['add', 'z2-3.4.5.6:7/sda9', 200]],
[['set_weight', 0, 150]],
[['remove', 1]]]}
parsed = parse_scenario(json.dumps(scenario))
self.assertEqual(parsed['replicas'], 3)
self.assertEqual(parsed['part_power'], 8)
self.assertEqual(parsed['random_seed'], 123)
self.assertEqual(parsed['overload'], 0)
self.assertEqual(parsed['rounds'], [
[['add', {'device': 'sda8',
'ip': '3.4.5.6',
'meta': '',
'port': 7,
'region': 1,
'replication_ip': None,
'replication_port': None,
'weight': 100.0,
'zone': 2}],
['add', {'device': u'sda9',
'ip': u'3.4.5.6',
'meta': '',
'port': 7,
'region': 1,
'replication_ip': None,
'replication_port': None,
'weight': 200.0,
'zone': 2}]],
[['set_weight', 0, 150.0]],
[['remove', 1]]])
# The rest of this test class is just a catalog of the myriad ways that
# the input can be malformed.
def test_invalid_json(self):
self.assertRaises(ValueError, parse_scenario, "{")
def test_json_not_object(self):
self.assertRaises(ValueError, parse_scenario, "[]")
self.assertRaises(ValueError, parse_scenario, "\"stuff\"")
def test_bad_replicas(self):
working_scenario = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0,
'rounds': [[['add', 'r1z2-3.4.5.6:7/sda8', 100]]]}
busted = dict(working_scenario)
del busted['replicas']
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, replicas='blahblah')
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, replicas=-1)
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_part_power(self):
working_scenario = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0,
'rounds': [[['add', 'r1z2-3.4.5.6:7/sda8', 100]]]}
busted = dict(working_scenario)
del busted['part_power']
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, part_power='blahblah')
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, part_power=0)
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, part_power=33)
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_random_seed(self):
working_scenario = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0,
'rounds': [[['add', 'r1z2-3.4.5.6:7/sda8', 100]]]}
busted = dict(working_scenario)
del busted['random_seed']
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, random_seed='blahblah')
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_overload(self):
working_scenario = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0,
'rounds': [[['add', 'r1z2-3.4.5.6:7/sda8', 100]]]}
busted = dict(working_scenario)
del busted['overload']
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, overload='blahblah')
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(working_scenario, overload=-0.01)
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_rounds(self):
base = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0}
self.assertRaises(ValueError, parse_scenario, json.dumps(base))
busted = dict(base, rounds={})
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(base, rounds=[{}])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
busted = dict(base, rounds=[[['bork']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_add(self):
base = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0}
# no dev
busted = dict(base, rounds=[[['add']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# no weight
busted = dict(base, rounds=[[['add', 'r1z2-1.2.3.4:6000/d7']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# too many fields
busted = dict(base, rounds=[[['add', 'r1z2-1.2.3.4:6000/d7', 1, 2]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# can't parse
busted = dict(base, rounds=[[['add', 'not a good value', 100]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# negative weight
busted = dict(base, rounds=[[['add', 'r1z2-1.2.3.4:6000/d7', -1]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_remove(self):
base = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0}
# no dev
busted = dict(base, rounds=[[['remove']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# bad dev id
busted = dict(base, rounds=[[['remove', 'not an int']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# too many fields
busted = dict(base, rounds=[[['remove', 1, 2]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
def test_bad_set_weight(self):
base = {
'replicas': 3, 'part_power': 8, 'random_seed': 123, 'overload': 0}
# no dev
busted = dict(base, rounds=[[['set_weight']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# no weight
busted = dict(base, rounds=[[['set_weight', 0]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# bad dev id
busted = dict(base, rounds=[[['set_weight', 'not an int', 90]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# negative weight
busted = dict(base, rounds=[[['set_weight', 1, -1]]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))
# bogus weight
busted = dict(base, rounds=[[['set_weight', 1, 'bogus']]])
self.assertRaises(ValueError, parse_scenario, json.dumps(busted))