sdk/python/tests/test_keep_client.py

   1 import hashlib
   2 import mock
   3 import os
   4 import random
   5 import re
   6 import socket
   7 import unittest
   8 import urlparse
   9
  10 import arvados
  11 import arvados.retry
  12 import arvados_testutil as tutil
  13 import run_test_server
  14
  15 class KeepTestCase(run_test_server.TestCaseWithServers):
  16     MAIN_SERVER = {}
  17     KEEP_SERVER = {}
  18
  19     @classmethod
  20     def setUpClass(cls):
  21         super(KeepTestCase, cls).setUpClass()
  22         run_test_server.authorize_with("admin")
  23         cls.api_client = arvados.api('v1')
  24         cls.keep_client = arvados.KeepClient(api_client=cls.api_client,
  25                                              proxy='', local_store='')
  26
  27     def test_KeepBasicRWTest(self):
  28         foo_locator = self.keep_client.put('foo')
  29         self.assertRegexpMatches(
  30             foo_locator,
  31             '^acbd18db4cc2f85cedef654fccc4a4d8\+3',
  32             'wrong md5 hash from Keep.put("foo"): ' + foo_locator)
  33         self.assertEqual(self.keep_client.get(foo_locator),
  34                          'foo',
  35                          'wrong content from Keep.get(md5("foo"))')
  36
  37     def test_KeepBinaryRWTest(self):
  38         blob_str = '\xff\xfe\xf7\x00\x01\x02'
  39         blob_locator = self.keep_client.put(blob_str)
  40         self.assertRegexpMatches(
  41             blob_locator,
  42             '^7fc7c53b45e53926ba52821140fef396\+6',
  43             ('wrong locator from Keep.put(<binarydata>):' + blob_locator))
  44         self.assertEqual(self.keep_client.get(blob_locator),
  45                          blob_str,
  46                          'wrong content from Keep.get(md5(<binarydata>))')
  47
  48     def test_KeepLongBinaryRWTest(self):
  49         blob_str = '\xff\xfe\xfd\xfc\x00\x01\x02\x03'
  50         for i in range(0,23):
  51             blob_str = blob_str + blob_str
  52         blob_locator = self.keep_client.put(blob_str)
  53         self.assertRegexpMatches(
  54             blob_locator,
  55             '^84d90fc0d8175dd5dcfab04b999bc956\+67108864',
  56             ('wrong locator from Keep.put(<binarydata>): ' + blob_locator))
  57         self.assertEqual(self.keep_client.get(blob_locator),
  58                          blob_str,
  59                          'wrong content from Keep.get(md5(<binarydata>))')
  60
  61     def test_KeepSingleCopyRWTest(self):
  62         blob_str = '\xff\xfe\xfd\xfc\x00\x01\x02\x03'
  63         blob_locator = self.keep_client.put(blob_str, copies=1)
  64         self.assertRegexpMatches(
  65             blob_locator,
  66             '^c902006bc98a3eb4a3663b65ab4a6fab\+8',
  67             ('wrong locator from Keep.put(<binarydata>): ' + blob_locator))
  68         self.assertEqual(self.keep_client.get(blob_locator),
  69                          blob_str,
  70                          'wrong content from Keep.get(md5(<binarydata>))')
  71
  72     def test_KeepEmptyCollectionTest(self):
  73         blob_locator = self.keep_client.put('', copies=1)
  74         self.assertRegexpMatches(
  75             blob_locator,
  76             '^d41d8cd98f00b204e9800998ecf8427e\+0',
  77             ('wrong locator from Keep.put(""): ' + blob_locator))
  78
  79
  80 class KeepPermissionTestCase(run_test_server.TestCaseWithServers):
  81     MAIN_SERVER = {}
  82     KEEP_SERVER = {'blob_signing_key': 'abcdefghijk0123456789',
  83                    'enforce_permissions': True}
  84
  85     def test_KeepBasicRWTest(self):
  86         run_test_server.authorize_with('active')
  87         keep_client = arvados.KeepClient()
  88         foo_locator = keep_client.put('foo')
  89         self.assertRegexpMatches(
  90             foo_locator,
  91             r'^acbd18db4cc2f85cedef654fccc4a4d8\+3\+A[a-f0-9]+@[a-f0-9]+$',
  92             'invalid locator from Keep.put("foo"): ' + foo_locator)
  93         self.assertEqual(keep_client.get(foo_locator),
  94                          'foo',
  95                          'wrong content from Keep.get(md5("foo"))')
  96
  97         # GET with an unsigned locator => NotFound
  98         bar_locator = keep_client.put('bar')
  99         unsigned_bar_locator = "37b51d194a7513e45b56f6524f2d51f2+3"
 100         self.assertRegexpMatches(
 101             bar_locator,
 102             r'^37b51d194a7513e45b56f6524f2d51f2\+3\+A[a-f0-9]+@[a-f0-9]+$',
 103             'invalid locator from Keep.put("bar"): ' + bar_locator)
 104         self.assertRaises(arvados.errors.NotFoundError,
 105                           keep_client.get,
 106                           unsigned_bar_locator)
 107
 108         # GET from a different user => NotFound
 109         run_test_server.authorize_with('spectator')
 110         self.assertRaises(arvados.errors.NotFoundError,
 111                           arvados.Keep.get,
 112                           bar_locator)
 113
 114         # Unauthenticated GET for a signed locator => NotFound
 115         # Unauthenticated GET for an unsigned locator => NotFound
 116         keep_client.api_token = ''
 117         self.assertRaises(arvados.errors.NotFoundError,
 118                           keep_client.get,
 119                           bar_locator)
 120         self.assertRaises(arvados.errors.NotFoundError,
 121                           keep_client.get,
 122                           unsigned_bar_locator)
 123
 124
 125 # KeepOptionalPermission: starts Keep with --permission-key-file
 126 # but not --enforce-permissions (i.e. generate signatures on PUT
 127 # requests, but do not require them for GET requests)
 128 #
 129 # All of these requests should succeed when permissions are optional:
 130 # * authenticated request, signed locator
 131 # * authenticated request, unsigned locator
 132 # * unauthenticated request, signed locator
 133 # * unauthenticated request, unsigned locator
 134 class KeepOptionalPermission(run_test_server.TestCaseWithServers):
 135     MAIN_SERVER = {}
 136     KEEP_SERVER = {'blob_signing_key': 'abcdefghijk0123456789',
 137                    'enforce_permissions': False}
 138
 139     @classmethod
 140     def setUpClass(cls):
 141         super(KeepOptionalPermission, cls).setUpClass()
 142         run_test_server.authorize_with("admin")
 143         cls.api_client = arvados.api('v1')
 144
 145     def setUp(self):
 146         super(KeepOptionalPermission, self).setUp()
 147         self.keep_client = arvados.KeepClient(api_client=self.api_client,
 148                                               proxy='', local_store='')
 149
 150     def _put_foo_and_check(self):
 151         signed_locator = self.keep_client.put('foo')
 152         self.assertRegexpMatches(
 153             signed_locator,
 154             r'^acbd18db4cc2f85cedef654fccc4a4d8\+3\+A[a-f0-9]+@[a-f0-9]+$',
 155             'invalid locator from Keep.put("foo"): ' + signed_locator)
 156         return signed_locator
 157
 158     def test_KeepAuthenticatedSignedTest(self):
 159         signed_locator = self._put_foo_and_check()
 160         self.assertEqual(self.keep_client.get(signed_locator),
 161                          'foo',
 162                          'wrong content from Keep.get(md5("foo"))')
 163
 164     def test_KeepAuthenticatedUnsignedTest(self):
 165         signed_locator = self._put_foo_and_check()
 166         self.assertEqual(self.keep_client.get("acbd18db4cc2f85cedef654fccc4a4d8"),
 167                          'foo',
 168                          'wrong content from Keep.get(md5("foo"))')
 169
 170     def test_KeepUnauthenticatedSignedTest(self):
 171         # Check that signed GET requests work even when permissions
 172         # enforcement is off.
 173         signed_locator = self._put_foo_and_check()
 174         self.keep_client.api_token = ''
 175         self.assertEqual(self.keep_client.get(signed_locator),
 176                          'foo',
 177                          'wrong content from Keep.get(md5("foo"))')
 178
 179     def test_KeepUnauthenticatedUnsignedTest(self):
 180         # Since --enforce-permissions is not in effect, GET requests
 181         # need not be authenticated.
 182         signed_locator = self._put_foo_and_check()
 183         self.keep_client.api_token = ''
 184         self.assertEqual(self.keep_client.get("acbd18db4cc2f85cedef654fccc4a4d8"),
 185                          'foo',
 186                          'wrong content from Keep.get(md5("foo"))')
 187
 188
 189 class KeepProxyTestCase(run_test_server.TestCaseWithServers):
 190     MAIN_SERVER = {}
 191     KEEP_SERVER = {}
 192     KEEP_PROXY_SERVER = {}
 193
 194     @classmethod
 195     def setUpClass(cls):
 196         super(KeepProxyTestCase, cls).setUpClass()
 197         run_test_server.authorize_with('active')
 198         cls.api_client = arvados.api('v1')
 199
 200     def tearDown(self):
 201         arvados.config.settings().pop('ARVADOS_EXTERNAL_CLIENT', None)
 202         super(KeepProxyTestCase, self).tearDown()
 203
 204     def test_KeepProxyTest1(self):
 205         # Will use ARVADOS_KEEP_PROXY environment variable that is set by
 206         # setUpClass().
 207         keep_client = arvados.KeepClient(api_client=self.api_client,
 208                                          local_store='')
 209         baz_locator = keep_client.put('baz')
 210         self.assertRegexpMatches(
 211             baz_locator,
 212             '^73feffa4b7f6bb68e44cf984c85f6e88\+3',
 213             'wrong md5 hash from Keep.put("baz"): ' + baz_locator)
 214         self.assertEqual(keep_client.get(baz_locator),
 215                          'baz',
 216                          'wrong content from Keep.get(md5("baz"))')
 217         self.assertTrue(keep_client.using_proxy)
 218
 219     def test_KeepProxyTest2(self):
 220         # Don't instantiate the proxy directly, but set the X-External-Client
 221         # header.  The API server should direct us to the proxy.
 222         arvados.config.settings()['ARVADOS_EXTERNAL_CLIENT'] = 'true'
 223         keep_client = arvados.KeepClient(api_client=self.api_client,
 224                                          proxy='', local_store='')
 225         baz_locator = keep_client.put('baz2')
 226         self.assertRegexpMatches(
 227             baz_locator,
 228             '^91f372a266fe2bf2823cb8ec7fda31ce\+4',
 229             'wrong md5 hash from Keep.put("baz2"): ' + baz_locator)
 230         self.assertEqual(keep_client.get(baz_locator),
 231                          'baz2',
 232                          'wrong content from Keep.get(md5("baz2"))')
 233         self.assertTrue(keep_client.using_proxy)
 234
 235
 236 class KeepClientServiceTestCase(unittest.TestCase, tutil.ApiClientMock):
 237     def get_service_roots(self, api_client):
 238         keep_client = arvados.KeepClient(api_client=api_client)
 239         services = keep_client.weighted_service_roots('000000')
 240         return [urlparse.urlparse(url) for url in sorted(services)]
 241
 242     def test_ssl_flag_respected_in_roots(self):
 243         for ssl_flag in [False, True]:
 244             services = self.get_service_roots(self.mock_keep_services(
 245                 service_ssl_flag=ssl_flag))
 246             self.assertEqual(
 247                 ('https' if ssl_flag else 'http'), services[0].scheme)
 248
 249     def test_correct_ports_with_ipv6_addresses(self):
 250         service = self.get_service_roots(self.mock_keep_services(
 251             service_type='proxy', service_host='100::1', service_port=10, count=1))[0]
 252         self.assertEqual('100::1', service.hostname)
 253         self.assertEqual(10, service.port)
 254
 255     # test_get_timeout and test_put_timeout test that
 256     # KeepClient.get and KeepClient.put use the appropriate timeouts
 257     # when connected directly to a Keep server (i.e. non-proxy timeout)
 258
 259     def test_get_timeout(self):
 260         api_client = self.mock_keep_services(count=1)
 261         keep_client = arvados.KeepClient(api_client=api_client)
 262         force_timeout = [socket.timeout("timed out")]
 263         with mock.patch('requests.get', side_effect=force_timeout) as mock_request:
 264             with self.assertRaises(arvados.errors.KeepReadError):
 265                 keep_client.get('ffffffffffffffffffffffffffffffff')
 266             self.assertTrue(mock_request.called)
 267             self.assertEqual(
 268                 arvados.KeepClient.DEFAULT_TIMEOUT,
 269                 mock_request.call_args[1]['timeout'])
 270
 271     def test_put_timeout(self):
 272         api_client = self.mock_keep_services(count=1)
 273         keep_client = arvados.KeepClient(api_client=api_client)
 274         force_timeout = [socket.timeout("timed out")]
 275         with mock.patch('requests.put', side_effect=force_timeout) as mock_request:
 276             with self.assertRaises(arvados.errors.KeepWriteError):
 277                 keep_client.put('foo')
 278             self.assertTrue(mock_request.called)
 279             self.assertEqual(
 280                 arvados.KeepClient.DEFAULT_TIMEOUT,
 281                 mock_request.call_args[1]['timeout'])
 282
 283     def test_proxy_get_timeout(self):
 284         # Force a timeout, verifying that the requests.get or
 285         # requests.put method was called with the proxy_timeout
 286         # setting rather than the default timeout.
 287         api_client = self.mock_keep_services(service_type='proxy', count=1)
 288         keep_client = arvados.KeepClient(api_client=api_client)
 289         force_timeout = [socket.timeout("timed out")]
 290         with mock.patch('requests.get', side_effect=force_timeout) as mock_request:
 291             with self.assertRaises(arvados.errors.KeepReadError):
 292                 keep_client.get('ffffffffffffffffffffffffffffffff')
 293             self.assertTrue(mock_request.called)
 294             self.assertEqual(
 295                 arvados.KeepClient.DEFAULT_PROXY_TIMEOUT,
 296                 mock_request.call_args[1]['timeout'])
 297
 298     def test_proxy_put_timeout(self):
 299         # Force a timeout, verifying that the requests.get or
 300         # requests.put method was called with the proxy_timeout
 301         # setting rather than the default timeout.
 302         api_client = self.mock_keep_services(service_type='proxy', count=1)
 303         keep_client = arvados.KeepClient(api_client=api_client)
 304         force_timeout = [socket.timeout("timed out")]
 305         with mock.patch('requests.put', side_effect=force_timeout) as mock_request:
 306             with self.assertRaises(arvados.errors.KeepWriteError):
 307                 keep_client.put('foo')
 308             self.assertTrue(mock_request.called)
 309             self.assertEqual(
 310                 arvados.KeepClient.DEFAULT_PROXY_TIMEOUT,
 311                 mock_request.call_args[1]['timeout'])
 312
 313     def test_probe_order_reference_set(self):
 314         # expected_order[i] is the probe order for
 315         # hash=md5(sprintf("%064x",i)) where there are 16 services
 316         # with uuid sprintf("anything-%015x",j) with j in 0..15. E.g.,
 317         # the first probe for the block consisting of 64 "0"
 318         # characters is the service whose uuid is
 319         # "zzzzz-bi6l4-000000000000003", so expected_order[0][0]=='3'.
 320         expected_order = [
 321             list('3eab2d5fc9681074'),
 322             list('097dba52e648f1c3'),
 323             list('c5b4e023f8a7d691'),
 324             list('9d81c02e76a3bf54'),
 325             ]
 326         hashes = [
 327             hashlib.md5("{:064x}".format(x)).hexdigest()
 328             for x in range(len(expected_order))]
 329         api_client = self.mock_keep_services(count=16)
 330         keep_client = arvados.KeepClient(api_client=api_client)
 331         for i, hash in enumerate(hashes):
 332             roots = keep_client.weighted_service_roots(hash)
 333             got_order = [
 334                 re.search(r'//\[?keep0x([0-9a-f]+)', root).group(1)
 335                 for root in roots]
 336             self.assertEqual(expected_order[i], got_order)
 337
 338     def test_probe_waste_adding_one_server(self):
 339         hashes = [
 340             hashlib.md5("{:064x}".format(x)).hexdigest() for x in range(100)]
 341         initial_services = 12
 342         api_client = self.mock_keep_services(count=initial_services)
 343         keep_client = arvados.KeepClient(api_client=api_client)
 344         probes_before = [
 345             keep_client.weighted_service_roots(hash) for hash in hashes]
 346         for added_services in range(1, 12):
 347             api_client = self.mock_keep_services(count=initial_services+added_services)
 348             keep_client = arvados.KeepClient(api_client=api_client)
 349             total_penalty = 0
 350             for hash_index in range(len(hashes)):
 351                 probe_after = keep_client.weighted_service_roots(
 352                     hashes[hash_index])
 353                 penalty = probe_after.index(probes_before[hash_index][0])
 354                 self.assertLessEqual(penalty, added_services)
 355                 total_penalty += penalty
 356             # Average penalty per block should not exceed
 357             # N(added)/N(orig) by more than 20%, and should get closer
 358             # to the ideal as we add data points.
 359             expect_penalty = (
 360                 added_services *
 361                 len(hashes) / initial_services)
 362             max_penalty = (
 363                 expect_penalty *
 364                 (120 - added_services)/100)
 365             min_penalty = (
 366                 expect_penalty * 8/10)
 367             self.assertTrue(
 368                 min_penalty <= total_penalty <= max_penalty,
 369                 "With {}+{} services, {} blocks, penalty {} but expected {}..{}".format(
 370                     initial_services,
 371                     added_services,
 372                     len(hashes),
 373                     total_penalty,
 374                     min_penalty,
 375                     max_penalty))
 376
 377     def check_64_zeros_error_order(self, verb, exc_class):
 378         data = '0' * 64
 379         if verb == 'get':
 380             data = hashlib.md5(data).hexdigest() + '+1234'
 381         # Arbitrary port number:
 382         aport = random.randint(1024,65535)
 383         api_client = self.mock_keep_services(service_port=aport, count=16)
 384         keep_client = arvados.KeepClient(api_client=api_client)
 385         with mock.patch('requests.' + verb,
 386                         side_effect=socket.timeout) as req_mock, \
 387                 self.assertRaises(exc_class) as err_check:
 388             getattr(keep_client, verb)(data)
 389         urls = [urlparse.urlparse(url)
 390                 for url in err_check.exception.service_errors()]
 391         self.assertEqual([('keep0x' + c, aport) for c in '3eab2d5fc9681074'],
 392                          [(url.hostname, url.port) for url in urls])
 393
 394     def test_get_error_shows_probe_order(self):
 395         self.check_64_zeros_error_order('get', arvados.errors.KeepReadError)
 396
 397     def test_put_error_shows_probe_order(self):
 398         self.check_64_zeros_error_order('put', arvados.errors.KeepWriteError)
 399
 400     def check_no_services_error(self, verb, exc_class):
 401         api_client = mock.MagicMock(name='api_client')
 402         api_client.keep_services().accessible().execute.side_effect = (
 403             arvados.errors.ApiError)
 404         keep_client = arvados.KeepClient(api_client=api_client)
 405         with self.assertRaises(exc_class) as err_check:
 406             getattr(keep_client, verb)('d41d8cd98f00b204e9800998ecf8427e+0')
 407         self.assertEqual(0, len(err_check.exception.service_errors()))
 408
 409     def test_get_error_with_no_services(self):
 410         self.check_no_services_error('get', arvados.errors.KeepReadError)
 411
 412     def test_put_error_with_no_services(self):
 413         self.check_no_services_error('put', arvados.errors.KeepWriteError)
 414
 415     def check_errors_from_last_retry(self, verb, exc_class):
 416         api_client = self.mock_keep_services(count=2)
 417         keep_client = arvados.KeepClient(api_client=api_client)
 418         req_mock = getattr(tutil, 'mock_{}_responses'.format(verb))(
 419             "retry error reporting test", 500, 500, 403, 403)
 420         with req_mock, tutil.skip_sleep, \
 421                 self.assertRaises(exc_class) as err_check:
 422             getattr(keep_client, verb)('d41d8cd98f00b204e9800998ecf8427e+0',
 423                                        num_retries=3)
 424         self.assertEqual([403, 403], [
 425                 getattr(error, 'status_code', None)
 426                 for error in err_check.exception.service_errors().itervalues()])
 427
 428     def test_get_error_reflects_last_retry(self):
 429         self.check_errors_from_last_retry('get', arvados.errors.KeepReadError)
 430
 431     def test_put_error_reflects_last_retry(self):
 432         self.check_errors_from_last_retry('put', arvados.errors.KeepWriteError)
 433
 434     def test_put_error_does_not_include_successful_puts(self):
 435         data = 'partial failure test'
 436         data_loc = '{}+{}'.format(hashlib.md5(data).hexdigest(), len(data))
 437         api_client = self.mock_keep_services(count=3)
 438         keep_client = arvados.KeepClient(api_client=api_client)
 439         with tutil.mock_put_responses(data_loc, 200, 500, 500) as req_mock, \
 440                 self.assertRaises(arvados.errors.KeepWriteError) as exc_check:
 441             keep_client.put(data)
 442         self.assertEqual(2, len(exc_check.exception.service_errors()))
 443
 444
 445 class KeepClientRetryTestMixin(object):
 446     # Testing with a local Keep store won't exercise the retry behavior.
 447     # Instead, our strategy is:
 448     # * Create a client with one proxy specified (pointed at a black
 449     #   hole), so there's no need to instantiate an API client, and
 450     #   all HTTP requests come from one place.
 451     # * Mock httplib's request method to provide simulated responses.
 452     # This lets us test the retry logic extensively without relying on any
 453     # supporting servers, and prevents side effects in case something hiccups.
 454     # To use this mixin, define DEFAULT_EXPECT, DEFAULT_EXCEPTION, and
 455     # run_method().
 456     #
 457     # Test classes must define TEST_PATCHER to a method that mocks
 458     # out appropriate methods in the client.
 459
 460     PROXY_ADDR = 'http://[%s]:65535/' % (tutil.TEST_HOST,)
 461     TEST_DATA = 'testdata'
 462     TEST_LOCATOR = 'ef654c40ab4f1747fc699915d4f70902+8'
 463
 464     def setUp(self):
 465         self.client_kwargs = {'proxy': self.PROXY_ADDR, 'local_store': ''}
 466
 467     def new_client(self, **caller_kwargs):
 468         kwargs = self.client_kwargs.copy()
 469         kwargs.update(caller_kwargs)
 470         return arvados.KeepClient(**kwargs)
 471
 472     def run_method(self, *args, **kwargs):
 473         raise NotImplementedError("test subclasses must define run_method")
 474
 475     def check_success(self, expected=None, *args, **kwargs):
 476         if expected is None:
 477             expected = self.DEFAULT_EXPECT
 478         self.assertEqual(expected, self.run_method(*args, **kwargs))
 479
 480     def check_exception(self, error_class=None, *args, **kwargs):
 481         if error_class is None:
 482             error_class = self.DEFAULT_EXCEPTION
 483         self.assertRaises(error_class, self.run_method, *args, **kwargs)
 484
 485     def test_immediate_success(self):
 486         with self.TEST_PATCHER(self.DEFAULT_EXPECT, 200):
 487             self.check_success()
 488
 489     def test_retry_then_success(self):
 490         with self.TEST_PATCHER(self.DEFAULT_EXPECT, 500, 200):
 491             self.check_success(num_retries=3)
 492
 493     def test_no_default_retry(self):
 494         with self.TEST_PATCHER(self.DEFAULT_EXPECT, 500, 200):
 495             self.check_exception()
 496
 497     def test_no_retry_after_permanent_error(self):
 498         with self.TEST_PATCHER(self.DEFAULT_EXPECT, 403, 200):
 499             self.check_exception(num_retries=3)
 500
 501     def test_error_after_retries_exhausted(self):
 502         with self.TEST_PATCHER(self.DEFAULT_EXPECT, 500, 500, 200):
 503             self.check_exception(num_retries=1)
 504
 505     def test_num_retries_instance_fallback(self):
 506         self.client_kwargs['num_retries'] = 3
 507         with self.TEST_PATCHER(self.DEFAULT_EXPECT, 500, 200):
 508             self.check_success()
 509
 510
 511 @tutil.skip_sleep
 512 class KeepClientRetryGetTestCase(KeepClientRetryTestMixin, unittest.TestCase):
 513     DEFAULT_EXPECT = KeepClientRetryTestMixin.TEST_DATA
 514     DEFAULT_EXCEPTION = arvados.errors.KeepReadError
 515     HINTED_LOCATOR = KeepClientRetryTestMixin.TEST_LOCATOR + '+K@xyzzy'
 516     TEST_PATCHER = staticmethod(tutil.mock_get_responses)
 517
 518     def run_method(self, locator=KeepClientRetryTestMixin.TEST_LOCATOR,
 519                    *args, **kwargs):
 520         return self.new_client().get(locator, *args, **kwargs)
 521
 522     def test_specific_exception_when_not_found(self):
 523         with tutil.mock_get_responses(self.DEFAULT_EXPECT, 404, 200):
 524             self.check_exception(arvados.errors.NotFoundError, num_retries=3)
 525
 526     def test_general_exception_with_mixed_errors(self):
 527         # get should raise a NotFoundError if no server returns the block,
 528         # and a high threshold of servers report that it's not found.
 529         # This test rigs up 50/50 disagreement between two servers, and
 530         # checks that it does not become a NotFoundError.
 531         client = self.new_client()
 532         with tutil.mock_get_responses(self.DEFAULT_EXPECT, 404, 500):
 533             with self.assertRaises(arvados.errors.KeepReadError) as exc_check:
 534                 client.get(self.HINTED_LOCATOR)
 535             self.assertNotIsInstance(
 536                 exc_check.exception, arvados.errors.NotFoundError,
 537                 "mixed errors raised NotFoundError")
 538
 539     def test_hint_server_can_succeed_without_retries(self):
 540         with tutil.mock_get_responses(self.DEFAULT_EXPECT, 404, 200, 500):
 541             self.check_success(locator=self.HINTED_LOCATOR)
 542
 543     def test_try_next_server_after_timeout(self):
 544         side_effects = [
 545             socket.timeout("timed out"),
 546             tutil.fake_requests_response(200, self.DEFAULT_EXPECT)]
 547         with mock.patch('requests.get',
 548                         side_effect=iter(side_effects)):
 549             self.check_success(locator=self.HINTED_LOCATOR)
 550
 551     def test_retry_data_with_wrong_checksum(self):
 552         side_effects = (tutil.fake_requests_response(200, s)
 553                         for s in ['baddata', self.TEST_DATA])
 554         with mock.patch('requests.get', side_effect=side_effects):
 555             self.check_success(locator=self.HINTED_LOCATOR)
 556
 557
 558 @tutil.skip_sleep
 559 class KeepClientRetryPutTestCase(KeepClientRetryTestMixin, unittest.TestCase):
 560     DEFAULT_EXPECT = KeepClientRetryTestMixin.TEST_LOCATOR
 561     DEFAULT_EXCEPTION = arvados.errors.KeepWriteError
 562     TEST_PATCHER = staticmethod(tutil.mock_put_responses)
 563
 564     def run_method(self, data=KeepClientRetryTestMixin.TEST_DATA,
 565                    copies=1, *args, **kwargs):
 566         return self.new_client().put(data, copies, *args, **kwargs)
 567
 568     def test_do_not_send_multiple_copies_to_same_server(self):
 569         with tutil.mock_put_responses(self.DEFAULT_EXPECT, 200):
 570             self.check_exception(copies=2, num_retries=3)