From: Kevan Carstensen Date: Fri, 14 May 2010 01:25:42 +0000 (-0700) Subject: Revisions of the #778 tests, per reviewers' comments X-Git-Url: https://git.rkrishnan.org/architecture.txt?a=commitdiff_plain;h=5683112a023468dbf65526db7799533b971afddc;p=tahoe-lafs%2Ftahoe-lafs.git Revisions of the #778 tests, per reviewers' comments - Fix comments and confusing naming. - Add tests for the new error messages suggested by David-Sarah and Zooko. - Alter existing tests for new error messages. - Make sure that the tests continue to work with the trunk. - Add a test for a mutual disjointedness assertion that I added to upload.servers_of_happiness. - Fix the comments to correctly reflect read-onlyness - Add a test for an edge case in should_add_server - Add an assertion to make sure that share redistribution works as it should - Alter tests to work with revised servers_of_happiness semantics - Remove tests for should_add_server, since that function no longer exists. - Alter tests to know about merge_peers, and to use it before calling servers_of_happiness. - Add tests for merge_peers. - Add Zooko's puzzles to the tests. - Edit encoding tests to expect the new kind of failure message. - Edit tests to expect error messages with the word "only" moved as far to the right as possible. - Extended and cleaned up some helper functions. - Changed some tests to call more appropriate helper functions. - Added a test for the failing redistribution algorithm - Added a test for the progress message - Added a test for the upper bound on readonly peer share discovery. --- diff --git a/src/allmydata/test/test_encode.py b/src/allmydata/test/test_encode.py index 7ba188f8..fb290a00 100644 --- a/src/allmydata/test/test_encode.py +++ b/src/allmydata/test/test_encode.py @@ -25,7 +25,7 @@ class FakeStorageBroker: class FakeBucketReaderWriterProxy: implements(IStorageBucketWriter, IStorageBucketReader) # these are used for both reading and writing - def __init__(self, mode="good"): + def __init__(self, mode="good", peerid="peer"): self.mode = mode self.blocks = {} self.plaintext_hashes = [] @@ -33,9 +33,10 @@ class FakeBucketReaderWriterProxy: self.block_hashes = None self.share_hashes = None self.closed = False + self.peerid = peerid def get_peerid(self): - return "peerid" + return self.peerid def _start(self): if self.mode == "lost-early": @@ -302,7 +303,7 @@ class Encode(unittest.TestCase): for shnum in range(NUM_SHARES): peer = FakeBucketReaderWriterProxy() shareholders[shnum] = peer - servermap[shnum] = str(shnum) + servermap.setdefault(shnum, set()).add(peer.get_peerid()) all_shareholders.append(peer) e.set_shareholders(shareholders, servermap) return e.start() @@ -459,12 +460,12 @@ class Roundtrip(unittest.TestCase, testutil.ShouldFailMixin): def _ready(res): k,happy,n = e.get_param("share_counts") assert n == NUM_SHARES # else we'll be completely confused - all_peers = [] + servermap = {} for shnum in range(NUM_SHARES): mode = bucket_modes.get(shnum, "good") - peer = FakeBucketReaderWriterProxy(mode) + peer = FakeBucketReaderWriterProxy(mode, "peer%d" % shnum) shareholders[shnum] = peer - servermap[shnum] = str(shnum) + servermap.setdefault(shnum, set()).add(peer.get_peerid()) e.set_shareholders(shareholders, servermap) return e.start() d.addCallback(_ready) diff --git a/src/allmydata/test/test_upload.py b/src/allmydata/test/test_upload.py index 985fc578..d9a18857 100644 --- a/src/allmydata/test/test_upload.py +++ b/src/allmydata/test/test_upload.py @@ -13,6 +13,8 @@ from allmydata.immutable import upload, encode from allmydata.interfaces import FileTooLargeError, UploadUnhappinessError from allmydata.util.assertutil import precondition from allmydata.util.deferredutil import DeferredListShouldSucceed +from allmydata.util.happinessutil import servers_of_happiness, \ + shares_by_server, merge_peers from no_network import GridTestMixin from common_util import ShouldFailMixin from allmydata.storage_client import StorageFarmBroker @@ -703,7 +705,7 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, num_segments = encoder.get_param("num_segments") d = selector.get_shareholders(broker, sh, storage_index, share_size, block_size, num_segments, - 10, 4) + 10, 3, 4) def _have_shareholders((used_peers, already_peers)): assert servers_to_break <= len(used_peers) for index in xrange(servers_to_break): @@ -715,7 +717,7 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, for peer in used_peers: buckets.update(peer.buckets) for bucket in peer.buckets: - servermap[bucket] = peer.peerid + servermap.setdefault(bucket, set()).add(peer.peerid) encoder.set_shareholders(buckets, servermap) d = encoder.start() return d @@ -725,7 +727,6 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, def _add_server(self, server_number, readonly=False): assert self.g, "I tried to find a grid at self.g, but failed" - assert self.shares, "I tried to find shares at self.shares, but failed" ss = self.g.make_server(server_number, readonly) self.g.add_server(server_number, ss) @@ -759,16 +760,24 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, self.failUnless((share_number, ss.my_nodeid, new_share_location) in shares) + def _setup_grid(self): + """ + I set up a NoNetworkGrid with a single server and client. + """ + self.set_up_grid(num_clients=1, num_servers=1) - def _setup_and_upload(self): + def _setup_and_upload(self, **kwargs): """ I set up a NoNetworkGrid with a single server and client, upload a file to it, store its uri in self.uri, and store its sharedata in self.shares. """ - self.set_up_grid(num_clients=1, num_servers=1) + self._setup_grid() client = self.g.clients[0] client.DEFAULT_ENCODING_PARAMETERS['happy'] = 1 + if "n" in kwargs and "k" in kwargs: + client.DEFAULT_ENCODING_PARAMETERS['k'] = kwargs['k'] + client.DEFAULT_ENCODING_PARAMETERS['n'] = kwargs['n'] data = upload.Data("data" * 10000, convergence="") self.data = data d = client.upload(data) @@ -804,7 +813,7 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, def _setUp(self, ns): - # Used by test_happy_semantics and test_prexisting_share_behavior + # Used by test_happy_semantics and test_preexisting_share_behavior # to set up the grid. self.node = FakeClient(mode="good", num_servers=ns) self.u = upload.Uploader() @@ -815,31 +824,29 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, def test_happy_semantics(self): self._setUp(2) DATA = upload.Data("kittens" * 10000, convergence="") - # These parameters are unsatisfiable with the client that we've made - # -- we'll use them to test that the semnatics work correctly. + # These parameters are unsatisfiable with only 2 servers. self.set_encoding_parameters(k=3, happy=5, n=10) d = self.shouldFail(UploadUnhappinessError, "test_happy_semantics", - "shares could only be placed on 2 servers " - "(5 were requested)", + "shares could be placed or found on only 2 " + "server(s). We were asked to place shares on " + "at least 5 server(s) such that any 3 of them " + "have enough shares to recover the file", self.u.upload, DATA) # Let's reset the client to have 10 servers d.addCallback(lambda ign: self._setUp(10)) - # These parameters are satisfiable with the client we've made. + # These parameters are satisfiable with 10 servers. d.addCallback(lambda ign: self.set_encoding_parameters(k=3, happy=5, n=10)) - # this should work d.addCallback(lambda ign: self.u.upload(DATA)) # Let's reset the client to have 7 servers # (this is less than n, but more than h) d.addCallback(lambda ign: self._setUp(7)) - # These encoding parameters should still be satisfiable with our - # client setup + # These parameters are satisfiable with 7 servers. d.addCallback(lambda ign: self.set_encoding_parameters(k=3, happy=5, n=10)) - # This, then, should work. d.addCallback(lambda ign: self.u.upload(DATA)) return d @@ -854,32 +861,36 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, # # The scenario in comment:52 proposes that we have a layout # like: - # server 1: share 1 - # server 2: share 1 - # server 3: share 1 - # server 4: shares 2 - 10 + # server 0: shares 1 - 9 + # server 1: share 0, read-only + # server 2: share 0, read-only + # server 3: share 0, read-only # To get access to the shares, we will first upload to one - # server, which will then have shares 1 - 10. We'll then + # server, which will then have shares 0 - 9. We'll then # add three new servers, configure them to not accept any new - # shares, then write share 1 directly into the serverdir of each. - # Then each of servers 1 - 3 will report that they have share 1, - # and will not accept any new share, while server 4 will report that - # it has shares 2 - 10 and will accept new shares. + # shares, then write share 0 directly into the serverdir of each, + # and then remove share 0 from server 0 in the same way. + # Then each of servers 1 - 3 will report that they have share 0, + # and will not accept any new share, while server 0 will report that + # it has shares 1 - 9 and will accept new shares. # We'll then set 'happy' = 4, and see that an upload fails # (as it should) d = self._setup_and_upload() d.addCallback(lambda ign: - self._add_server_with_share(1, 0, True)) + self._add_server_with_share(server_number=1, share_number=0, + readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(2, 0, True)) + self._add_server_with_share(server_number=2, share_number=0, + readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(3, 0, True)) + self._add_server_with_share(server_number=3, share_number=0, + readonly=True)) # Remove the first share from server 0. - def _remove_share_0(): + def _remove_share_0_from_server_0(): share_location = self.shares[0][2] os.remove(share_location) d.addCallback(lambda ign: - _remove_share_0()) + _remove_share_0_from_server_0()) # Set happy = 4 in the client. def _prepare(): client = self.g.clients[0] @@ -889,9 +900,15 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, _prepare()) # Uploading data should fail d.addCallback(lambda client: - self.shouldFail(UploadUnhappinessError, "test_happy_semantics", - "shares could only be placed on 2 servers " - "(4 were requested)", + self.shouldFail(UploadUnhappinessError, + "test_problem_layout_comment_52_test_1", + "shares could be placed or found on 4 server(s), " + "but they are not spread out evenly enough to " + "ensure that any 3 of these servers would have " + "enough shares to recover the file. " + "We were asked to place shares on at " + "least 4 servers such that any 3 of them have " + "enough shares to recover the file", client.upload, upload.Data("data" * 10000, convergence=""))) @@ -905,7 +922,7 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(lambda ign: self._setup_and_upload()) d.addCallback(lambda ign: - self._add_server_with_share(server_number=2)) + self._add_server(server_number=2)) d.addCallback(lambda ign: self._add_server_with_share(server_number=3, share_number=0, readonly=True)) @@ -914,14 +931,17 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, readonly=True)) def _prepare2(): client = self.g.clients[0] - client.DEFAULT_ENCODING_PARAMETERS['happy'] = 3 + client.DEFAULT_ENCODING_PARAMETERS['happy'] = 4 return client d.addCallback(lambda ign: _prepare2()) d.addCallback(lambda client: - self.shouldFail(UploadUnhappinessError, "test_happy_sematics", - "shares could only be placed on 2 servers " - "(3 were requested)", + self.shouldFail(UploadUnhappinessError, + "test_problem_layout_comment_52_test_2", + "shares could be placed on only 3 server(s) such " + "that any 3 of them have enough shares to recover " + "the file, but we were asked to place shares on " + "at least 4 such servers.", client.upload, upload.Data("data" * 10000, convergence=""))) return d @@ -935,15 +955,14 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, def _change_basedir(ign): self.basedir = self.mktemp() _change_basedir(None) - d = self._setup_and_upload() - # We start by uploading all of the shares to one server (which has - # already been done above). + # We start by uploading all of the shares to one server. # Next, we'll add three new servers to our NoNetworkGrid. We'll add # one share from our initial upload to each of these. # The counterintuitive ordering of the share numbers is to deal with # the permuting of these servers -- distributing the shares this # way ensures that the Tahoe2PeerSelector sees them in the order - # described above. + # described below. + d = self._setup_and_upload() d.addCallback(lambda ign: self._add_server_with_share(server_number=1, share_number=2)) d.addCallback(lambda ign: @@ -955,7 +974,7 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, # server 1: share 2 # server 2: share 0 # server 3: share 1 - # We want to change the 'happy' parameter in the client to 4. + # We change the 'happy' parameter in the client to 4. # The Tahoe2PeerSelector will see the peers permuted as: # 2, 3, 1, 0 # Ideally, a reupload of our original data should work. @@ -968,12 +987,19 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, client.upload(upload.Data("data" * 10000, convergence=""))) - # This scenario is basically comment:53, but with the order reversed; - # this means that the Tahoe2PeerSelector sees - # server 2: shares 1-10 - # server 3: share 1 - # server 1: share 2 - # server 4: share 3 + # This scenario is basically comment:53, but changed so that the + # Tahoe2PeerSelector sees the server with all of the shares before + # any of the other servers. + # The layout is: + # server 2: shares 0 - 9 + # server 3: share 0 + # server 1: share 1 + # server 4: share 2 + # The Tahoe2PeerSelector sees the peers permuted as: + # 2, 3, 1, 4 + # Note that server 0 has been replaced by server 4; this makes it + # easier to ensure that the last server seen by Tahoe2PeerSelector + # has only one share. d.addCallback(_change_basedir) d.addCallback(lambda ign: self._setup_and_upload()) @@ -985,7 +1011,7 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, self._add_server_with_share(server_number=1, share_number=2)) # Copy all of the other shares to server number 2 def _copy_shares(ign): - for i in xrange(1, 10): + for i in xrange(0, 10): self._copy_share_to_server(i, 2) d.addCallback(_copy_shares) # Remove the first server, and add a placeholder with share 0 @@ -997,9 +1023,16 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(_reset_encoding_parameters) d.addCallback(lambda client: client.upload(upload.Data("data" * 10000, convergence=""))) + + # Try the same thing, but with empty servers after the first one # We want to make sure that Tahoe2PeerSelector will redistribute # shares as necessary, not simply discover an existing layout. + # The layout is: + # server 2: shares 0 - 9 + # server 3: empty + # server 1: empty + # server 4: empty d.addCallback(_change_basedir) d.addCallback(lambda ign: self._setup_and_upload()) @@ -1009,14 +1042,18 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, self._add_server(server_number=3)) d.addCallback(lambda ign: self._add_server(server_number=1)) + d.addCallback(lambda ign: + self._add_server(server_number=4)) d.addCallback(_copy_shares) d.addCallback(lambda ign: self.g.remove_server(self.g.servers_by_number[0].my_nodeid)) - d.addCallback(lambda ign: - self._add_server(server_number=4)) d.addCallback(_reset_encoding_parameters) d.addCallback(lambda client: client.upload(upload.Data("data" * 10000, convergence=""))) + # Make sure that only as many shares as necessary to satisfy + # servers of happiness were pushed. + d.addCallback(lambda results: + self.failUnlessEqual(results.pushed_shares, 3)) return d @@ -1095,17 +1132,24 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, def test_dropped_servers_in_encoder(self): + # The Encoder does its own "servers_of_happiness" check if it + # happens to lose a bucket during an upload (it assumes that + # the layout presented to it satisfies "servers_of_happiness" + # until a failure occurs) + # + # This test simulates an upload where servers break after peer + # selection, but before they are written to. def _set_basedir(ign=None): self.basedir = self.mktemp() _set_basedir() d = self._setup_and_upload(); # Add 5 servers def _do_server_setup(ign): - self._add_server_with_share(1) - self._add_server_with_share(2) - self._add_server_with_share(3) - self._add_server_with_share(4) - self._add_server_with_share(5) + self._add_server(server_number=1) + self._add_server(server_number=2) + self._add_server(server_number=3) + self._add_server(server_number=4) + self._add_server(server_number=5) d.addCallback(_do_server_setup) # remove the original server # (necessary to ensure that the Tahoe2PeerSelector will distribute @@ -1114,11 +1158,13 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, server = self.g.servers_by_number[0] self.g.remove_server(server.my_nodeid) d.addCallback(_remove_server) - # This should succeed. + # This should succeed; we still have 4 servers, and the + # happiness of the upload is 4. d.addCallback(lambda ign: self._do_upload_with_broken_servers(1)) # Now, do the same thing over again, but drop 2 servers instead - # of 1. This should fail. + # of 1. This should fail, because servers_of_happiness is 4 and + # we can't satisfy that. d.addCallback(_set_basedir) d.addCallback(lambda ign: self._setup_and_upload()) @@ -1127,8 +1173,10 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(lambda ign: self.shouldFail(UploadUnhappinessError, "test_dropped_servers_in_encoder", - "lost too many servers during upload " - "(still have 3, want 4)", + "shares could be placed on only 3 server(s) " + "such that any 3 of them have enough shares to " + "recover the file, but we were asked to place " + "shares on at least 4", self._do_upload_with_broken_servers, 2)) # Now do the same thing over again, but make some of the servers # readonly, break some of the ones that aren't, and make sure that @@ -1137,9 +1185,9 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(lambda ign: self._setup_and_upload()) def _do_server_setup_2(ign): - self._add_server_with_share(1) - self._add_server_with_share(2) - self._add_server_with_share(3) + self._add_server(1) + self._add_server(2) + self._add_server(3) self._add_server_with_share(4, 7, readonly=True) self._add_server_with_share(5, 8, readonly=True) d.addCallback(_do_server_setup_2) @@ -1154,34 +1202,95 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(lambda ign: self.shouldFail(UploadUnhappinessError, "test_dropped_servers_in_encoder", - "lost too many servers during upload " - "(still have 3, want 4)", + "shares could be placed on only 3 server(s) " + "such that any 3 of them have enough shares to " + "recover the file, but we were asked to place " + "shares on at least 4", self._do_upload_with_broken_servers, 2)) return d - def test_servers_with_unique_shares(self): - # servers_with_unique_shares expects a dict of - # shnum => peerid as a preexisting shares argument. + def test_merge_peers(self): + # merge_peers merges a list of used_peers and a dict of + # shareid -> peerid mappings. + shares = { + 1 : set(["server1"]), + 2 : set(["server2"]), + 3 : set(["server3"]), + 4 : set(["server4", "server5"]), + 5 : set(["server1", "server2"]), + } + # if not provided with a used_peers argument, it should just + # return the first argument unchanged. + self.failUnlessEqual(shares, merge_peers(shares, set([]))) + class FakePeerTracker: + pass + trackers = [] + for (i, server) in [(i, "server%d" % i) for i in xrange(5, 9)]: + t = FakePeerTracker() + t.peerid = server + t.buckets = [i] + trackers.append(t) + expected = { + 1 : set(["server1"]), + 2 : set(["server2"]), + 3 : set(["server3"]), + 4 : set(["server4", "server5"]), + 5 : set(["server1", "server2", "server5"]), + 6 : set(["server6"]), + 7 : set(["server7"]), + 8 : set(["server8"]), + } + self.failUnlessEqual(expected, merge_peers(shares, set(trackers))) + shares2 = {} + expected = { + 5 : set(["server5"]), + 6 : set(["server6"]), + 7 : set(["server7"]), + 8 : set(["server8"]), + } + self.failUnlessEqual(expected, merge_peers(shares2, set(trackers))) + shares3 = {} + trackers = [] + expected = {} + for (i, server) in [(i, "server%d" % i) for i in xrange(10)]: + shares3[i] = set([server]) + t = FakePeerTracker() + t.peerid = server + t.buckets = [i] + trackers.append(t) + expected[i] = set([server]) + self.failUnlessEqual(expected, merge_peers(shares3, set(trackers))) + + + def test_servers_of_happiness_utility_function(self): + # These tests are concerned with the servers_of_happiness() + # utility function, and its underlying matching algorithm. Other + # aspects of the servers_of_happiness behavior are tested + # elsehwere These tests exist to ensure that + # servers_of_happiness doesn't under or overcount the happiness + # value for given inputs. + + # servers_of_happiness expects a dict of + # shnum => set(peerids) as a preexisting shares argument. test1 = { - 1 : "server1", - 2 : "server2", - 3 : "server3", - 4 : "server4" + 1 : set(["server1"]), + 2 : set(["server2"]), + 3 : set(["server3"]), + 4 : set(["server4"]) } - unique_servers = upload.servers_with_unique_shares(test1) - self.failUnlessEqual(4, len(unique_servers)) - for server in ["server1", "server2", "server3", "server4"]: - self.failUnlessIn(server, unique_servers) - test1[4] = "server1" - # Now there should only be 3 unique servers. - unique_servers = upload.servers_with_unique_shares(test1) - self.failUnlessEqual(3, len(unique_servers)) - for server in ["server1", "server2", "server3"]: - self.failUnlessIn(server, unique_servers) - # servers_with_unique_shares expects to receive some object with - # a peerid attribute. So we make a FakePeerTracker whose only - # job is to have a peerid attribute. + happy = servers_of_happiness(test1) + self.failUnlessEqual(4, happy) + test1[4] = set(["server1"]) + # We've added a duplicate server, so now servers_of_happiness + # should be 3 instead of 4. + happy = servers_of_happiness(test1) + self.failUnlessEqual(3, happy) + # The second argument of merge_peers should be a set of + # objects with peerid and buckets as attributes. In actual use, + # these will be PeerTracker instances, but for testing it is fine + # to make a FakePeerTracker whose job is to hold those instance + # variables to test that part. class FakePeerTracker: pass trackers = [] @@ -1190,52 +1299,116 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, t.peerid = server t.buckets = [i] trackers.append(t) - # Recall that there are 3 unique servers in test1. Since none of - # those overlap with the ones in trackers, we should get 7 back - unique_servers = upload.servers_with_unique_shares(test1, set(trackers)) - self.failUnlessEqual(7, len(unique_servers)) - expected_servers = ["server" + str(i) for i in xrange(1, 9)] - expected_servers.remove("server4") - for server in expected_servers: - self.failUnlessIn(server, unique_servers) - # Now add an overlapping server to trackers. + # Recall that test1 is a server layout with servers_of_happiness + # = 3. Since there isn't any overlap between the shnum -> + # set([peerid]) correspondences in test1 and those in trackers, + # the result here should be 7. + test2 = merge_peers(test1, set(trackers)) + happy = servers_of_happiness(test2) + self.failUnlessEqual(7, happy) + # Now add an overlapping server to trackers. This is redundant, + # so it should not cause the previously reported happiness value + # to change. t = FakePeerTracker() t.peerid = "server1" t.buckets = [1] trackers.append(t) - unique_servers = upload.servers_with_unique_shares(test1, set(trackers)) - self.failUnlessEqual(7, len(unique_servers)) - for server in expected_servers: - self.failUnlessIn(server, unique_servers) + test2 = merge_peers(test1, set(trackers)) + happy = servers_of_happiness(test2) + self.failUnlessEqual(7, happy) test = {} - unique_servers = upload.servers_with_unique_shares(test) - self.failUnlessEqual(0, len(test)) + happy = servers_of_happiness(test) + self.failUnlessEqual(0, happy) + # Test a more substantial overlap between the trackers and the + # existing assignments. + test = { + 1 : set(['server1']), + 2 : set(['server2']), + 3 : set(['server3']), + 4 : set(['server4']), + } + trackers = [] + t = FakePeerTracker() + t.peerid = 'server5' + t.buckets = [4] + trackers.append(t) + t = FakePeerTracker() + t.peerid = 'server6' + t.buckets = [3, 5] + trackers.append(t) + # The value returned by servers_of_happiness is the size + # of a maximum matching in the bipartite graph that + # servers_of_happiness() makes between peerids and share + # numbers. It should find something like this: + # (server 1, share 1) + # (server 2, share 2) + # (server 3, share 3) + # (server 5, share 4) + # (server 6, share 5) + # + # and, since there are 5 edges in this matching, it should + # return 5. + test2 = merge_peers(test, set(trackers)) + happy = servers_of_happiness(test2) + self.failUnlessEqual(5, happy) + # Zooko's first puzzle: + # (from http://allmydata.org/trac/tahoe-lafs/ticket/778#comment:156) + # + # server 1: shares 0, 1 + # server 2: shares 1, 2 + # server 3: share 2 + # + # This should yield happiness of 3. + test = { + 0 : set(['server1']), + 1 : set(['server1', 'server2']), + 2 : set(['server2', 'server3']), + } + self.failUnlessEqual(3, servers_of_happiness(test)) + # Zooko's second puzzle: + # (from http://allmydata.org/trac/tahoe-lafs/ticket/778#comment:158) + # + # server 1: shares 0, 1 + # server 2: share 1 + # + # This should yield happiness of 2. + test = { + 0 : set(['server1']), + 1 : set(['server1', 'server2']), + } + self.failUnlessEqual(2, servers_of_happiness(test)) def test_shares_by_server(self): - test = dict([(i, "server%d" % i) for i in xrange(1, 5)]) - shares_by_server = upload.shares_by_server(test) - self.failUnlessEqual(set([1]), shares_by_server["server1"]) - self.failUnlessEqual(set([2]), shares_by_server["server2"]) - self.failUnlessEqual(set([3]), shares_by_server["server3"]) - self.failUnlessEqual(set([4]), shares_by_server["server4"]) + test = dict([(i, set(["server%d" % i])) for i in xrange(1, 5)]) + sbs = shares_by_server(test) + self.failUnlessEqual(set([1]), sbs["server1"]) + self.failUnlessEqual(set([2]), sbs["server2"]) + self.failUnlessEqual(set([3]), sbs["server3"]) + self.failUnlessEqual(set([4]), sbs["server4"]) test1 = { - 1 : "server1", - 2 : "server1", - 3 : "server1", - 4 : "server2", - 5 : "server2" + 1 : set(["server1"]), + 2 : set(["server1"]), + 3 : set(["server1"]), + 4 : set(["server2"]), + 5 : set(["server2"]) } - shares_by_server = upload.shares_by_server(test1) - self.failUnlessEqual(set([1, 2, 3]), shares_by_server["server1"]) - self.failUnlessEqual(set([4, 5]), shares_by_server["server2"]) + sbs = shares_by_server(test1) + self.failUnlessEqual(set([1, 2, 3]), sbs["server1"]) + self.failUnlessEqual(set([4, 5]), sbs["server2"]) + # This should fail unless the peerid part of the mapping is a set + test2 = {1: "server1"} + self.shouldFail(AssertionError, + "test_shares_by_server", + "", + shares_by_server, test2) def test_existing_share_detection(self): self.basedir = self.mktemp() d = self._setup_and_upload() # Our final setup should look like this: - # server 1: shares 1 - 10, read-only + # server 1: shares 0 - 9, read-only # server 2: empty # server 3: empty # server 4: empty @@ -1246,11 +1419,11 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(lambda ign: self._add_server_with_share(1, 0, True)) d.addCallback(lambda ign: - self._add_server_with_share(2)) + self._add_server(2)) d.addCallback(lambda ign: - self._add_server_with_share(3)) + self._add_server(3)) d.addCallback(lambda ign: - self._add_server_with_share(4)) + self._add_server(4)) def _copy_shares(ign): for i in xrange(1, 10): self._copy_share_to_server(i, 1) @@ -1267,35 +1440,127 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, return d - def test_should_add_server(self): - shares = dict([(i, "server%d" % i) for i in xrange(10)]) - self.failIf(upload.should_add_server(shares, "server1", 4)) - shares[4] = "server1" - self.failUnless(upload.should_add_server(shares, "server4", 4)) - shares = {} - self.failUnless(upload.should_add_server(shares, "server1", 1)) + def test_query_counting(self): + # If peer selection fails, Tahoe2PeerSelector prints out a lot + # of helpful diagnostic information, including query stats. + # This test helps make sure that that information is accurate. + self.basedir = self.mktemp() + d = self._setup_and_upload() + def _setup(ign): + for i in xrange(1, 11): + self._add_server(server_number=i) + self.g.remove_server(self.g.servers_by_number[0].my_nodeid) + c = self.g.clients[0] + # We set happy to an unsatisfiable value so that we can check the + # counting in the exception message. The same progress message + # is also used when the upload is successful, but in that case it + # only gets written to a log, so we can't see what it says. + c.DEFAULT_ENCODING_PARAMETERS['happy'] = 45 + return c + d.addCallback(_setup) + d.addCallback(lambda c: + self.shouldFail(UploadUnhappinessError, "test_query_counting", + "10 queries placed some shares", + c.upload, upload.Data("data" * 10000, + convergence=""))) + # Now try with some readonly servers. We want to make sure that + # the readonly peer share discovery phase is counted correctly. + def _reset(ign): + self.basedir = self.mktemp() + self.g = None + d.addCallback(_reset) + d.addCallback(lambda ign: + self._setup_and_upload()) + def _then(ign): + for i in xrange(1, 11): + self._add_server(server_number=i) + self._add_server(server_number=11, readonly=True) + self._add_server(server_number=12, readonly=True) + self.g.remove_server(self.g.servers_by_number[0].my_nodeid) + c = self.g.clients[0] + c.DEFAULT_ENCODING_PARAMETERS['happy'] = 45 + return c + d.addCallback(_then) + d.addCallback(lambda c: + self.shouldFail(UploadUnhappinessError, "test_query_counting", + "2 placed none (of which 2 placed none due to " + "the server being full", + c.upload, upload.Data("data" * 10000, + convergence=""))) + # Now try the case where the upload process finds a bunch of the + # shares that it wants to place on the first server, including + # the one that it wanted to allocate there. Though no shares will + # be allocated in this request, it should still be called + # productive, since it caused some homeless shares to be + # removed. + d.addCallback(_reset) + d.addCallback(lambda ign: + self._setup_and_upload()) + + def _next(ign): + for i in xrange(1, 11): + self._add_server(server_number=i) + # Copy all of the shares to server 9, since that will be + # the first one that the selector sees. + for i in xrange(10): + self._copy_share_to_server(i, 9) + # Remove server 0, and its contents + self.g.remove_server(self.g.servers_by_number[0].my_nodeid) + # Make happiness unsatisfiable + c = self.g.clients[0] + c.DEFAULT_ENCODING_PARAMETERS['happy'] = 45 + return c + d.addCallback(_next) + d.addCallback(lambda c: + self.shouldFail(UploadUnhappinessError, "test_query_counting", + "1 queries placed some shares", + c.upload, upload.Data("data" * 10000, + convergence=""))) + return d + + + def test_upper_limit_on_readonly_queries(self): + self.basedir = self.mktemp() + d = self._setup_and_upload() + def _then(ign): + for i in xrange(1, 11): + self._add_server(server_number=i, readonly=True) + self.g.remove_server(self.g.servers_by_number[0].my_nodeid) + c = self.g.clients[0] + c.DEFAULT_ENCODING_PARAMETERS['k'] = 2 + c.DEFAULT_ENCODING_PARAMETERS['happy'] = 4 + c.DEFAULT_ENCODING_PARAMETERS['n'] = 4 + return c + d.addCallback(_then) + d.addCallback(lambda client: + self.shouldFail(UploadUnhappinessError, + "test_upper_limit_on_readonly_queries", + "sent 8 queries to 8 peers", + client.upload, + upload.Data('data' * 10000, convergence=""))) + return d def test_exception_messages_during_peer_selection(self): - # server 1: readonly, no shares - # server 2: readonly, no shares - # server 3: readonly, no shares - # server 4: readonly, no shares - # server 5: readonly, no shares + # server 1: read-only, no shares + # server 2: read-only, no shares + # server 3: read-only, no shares + # server 4: read-only, no shares + # server 5: read-only, no shares # This will fail, but we want to make sure that the log messages # are informative about why it has failed. self.basedir = self.mktemp() d = self._setup_and_upload() d.addCallback(lambda ign: - self._add_server_with_share(server_number=1, readonly=True)) + self._add_server(server_number=1, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=2, readonly=True)) + self._add_server(server_number=2, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=3, readonly=True)) + self._add_server(server_number=3, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=4, readonly=True)) + self._add_server(server_number=4, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=5, readonly=True)) + self._add_server(server_number=5, readonly=True)) d.addCallback(lambda ign: self.g.remove_server(self.g.servers_by_number[0].my_nodeid)) def _reset_encoding_parameters(ign): @@ -1305,10 +1570,11 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, d.addCallback(_reset_encoding_parameters) d.addCallback(lambda client: self.shouldFail(UploadUnhappinessError, "test_selection_exceptions", - "peer selection failed for : placed 0 shares out of 10 " - "total (10 homeless), want to place on 4 servers," - " sent 5 queries to 5 peers, 0 queries placed " + "placed 0 shares out of 10 " + "total (10 homeless), want to place shares on at " + "least 4 servers such that any 3 of them have " + "enough shares to recover the file, " + "sent 5 queries to 5 peers, 0 queries placed " "some shares, 5 placed none " "(of which 5 placed none due to the server being " "full and 0 placed none due to an error)", @@ -1316,52 +1582,161 @@ class EncodingParameters(GridTestMixin, unittest.TestCase, SetDEPMixin, upload.Data("data" * 10000, convergence=""))) - # server 1: readonly, no shares + # server 1: read-only, no shares # server 2: broken, no shares - # server 3: readonly, no shares - # server 4: readonly, no shares - # server 5: readonly, no shares + # server 3: read-only, no shares + # server 4: read-only, no shares + # server 5: read-only, no shares def _reset(ign): self.basedir = self.mktemp() d.addCallback(_reset) d.addCallback(lambda ign: self._setup_and_upload()) d.addCallback(lambda ign: - self._add_server_with_share(server_number=1, readonly=True)) + self._add_server(server_number=1, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=2)) + self._add_server(server_number=2)) def _break_server_2(ign): server = self.g.servers_by_number[2].my_nodeid # We have to break the server in servers_by_id, - # because the ones in servers_by_number isn't wrapped, - # and doesn't look at its broken attribute + # because the one in servers_by_number isn't wrapped, + # and doesn't look at its broken attribute when answering + # queries. self.g.servers_by_id[server].broken = True d.addCallback(_break_server_2) d.addCallback(lambda ign: - self._add_server_with_share(server_number=3, readonly=True)) + self._add_server(server_number=3, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=4, readonly=True)) + self._add_server(server_number=4, readonly=True)) d.addCallback(lambda ign: - self._add_server_with_share(server_number=5, readonly=True)) + self._add_server(server_number=5, readonly=True)) d.addCallback(lambda ign: self.g.remove_server(self.g.servers_by_number[0].my_nodeid)) - def _reset_encoding_parameters(ign): + def _reset_encoding_parameters(ign, happy=4): client = self.g.clients[0] - client.DEFAULT_ENCODING_PARAMETERS['happy'] = 4 + client.DEFAULT_ENCODING_PARAMETERS['happy'] = happy return client d.addCallback(_reset_encoding_parameters) d.addCallback(lambda client: self.shouldFail(UploadUnhappinessError, "test_selection_exceptions", - "peer selection failed for : placed 0 shares out of 10 " - "total (10 homeless), want to place on 4 servers," - " sent 5 queries to 5 peers, 0 queries placed " + "placed 0 shares out of 10 " + "total (10 homeless), want to place shares on at " + "least 4 servers such that any 3 of them have " + "enough shares to recover the file, " + "sent 5 queries to 5 peers, 0 queries placed " "some shares, 5 placed none " "(of which 4 placed none due to the server being " "full and 1 placed none due to an error)", client.upload, upload.Data("data" * 10000, convergence=""))) + # server 0, server 1 = empty, accepting shares + # This should place all of the shares, but still fail with happy=4. + # We want to make sure that the exception message is worded correctly. + d.addCallback(_reset) + d.addCallback(lambda ign: + self._setup_grid()) + d.addCallback(lambda ign: + self._add_server(server_number=1)) + d.addCallback(_reset_encoding_parameters) + d.addCallback(lambda client: + self.shouldFail(UploadUnhappinessError, "test_selection_exceptions", + "shares could be placed or found on only 2 " + "server(s). We were asked to place shares on at " + "least 4 server(s) such that any 3 of them have " + "enough shares to recover the file.", + client.upload, upload.Data("data" * 10000, + convergence=""))) + # servers 0 - 4 = empty, accepting shares + # This too should place all the shares, and this too should fail, + # but since the effective happiness is more than the k encoding + # parameter, it should trigger a different error message than the one + # above. + d.addCallback(_reset) + d.addCallback(lambda ign: + self._setup_grid()) + d.addCallback(lambda ign: + self._add_server(server_number=1)) + d.addCallback(lambda ign: + self._add_server(server_number=2)) + d.addCallback(lambda ign: + self._add_server(server_number=3)) + d.addCallback(lambda ign: + self._add_server(server_number=4)) + d.addCallback(_reset_encoding_parameters, happy=7) + d.addCallback(lambda client: + self.shouldFail(UploadUnhappinessError, "test_selection_exceptions", + "shares could be placed on only 5 server(s) such " + "that any 3 of them have enough shares to recover " + "the file, but we were asked to place shares on " + "at least 7 such servers.", + client.upload, upload.Data("data" * 10000, + convergence=""))) + # server 0: shares 0 - 9 + # server 1: share 0, read-only + # server 2: share 0, read-only + # server 3: share 0, read-only + # This should place all of the shares, but fail with happy=4. + # Since the number of servers with shares is more than the number + # necessary to reconstitute the file, this will trigger a different + # error message than either of those above. + d.addCallback(_reset) + d.addCallback(lambda ign: + self._setup_and_upload()) + d.addCallback(lambda ign: + self._add_server_with_share(server_number=1, share_number=0, + readonly=True)) + d.addCallback(lambda ign: + self._add_server_with_share(server_number=2, share_number=0, + readonly=True)) + d.addCallback(lambda ign: + self._add_server_with_share(server_number=3, share_number=0, + readonly=True)) + d.addCallback(_reset_encoding_parameters, happy=7) + d.addCallback(lambda client: + self.shouldFail(UploadUnhappinessError, "test_selection_exceptions", + "shares could be placed or found on 4 server(s), " + "but they are not spread out evenly enough to " + "ensure that any 3 of these servers would have " + "enough shares to recover the file. We were asked " + "to place shares on at least 7 servers such that " + "any 3 of them have enough shares to recover the " + "file", + client.upload, upload.Data("data" * 10000, + convergence=""))) + return d + + + def test_problem_layout_comment_187(self): + # #778 comment 187 broke an initial attempt at a share + # redistribution algorithm. This test is here to demonstrate the + # breakage, and to test that subsequent algorithms don't also + # break in the same way. + self.basedir = self.mktemp() + d = self._setup_and_upload(k=2, n=3) + + # server 1: shares 0, 1, 2, readonly + # server 2: share 0, readonly + # server 3: share 0 + def _setup(ign): + self._add_server_with_share(server_number=1, share_number=0, + readonly=True) + self._add_server_with_share(server_number=2, share_number=0, + readonly=True) + self._add_server_with_share(server_number=3, share_number=0) + # Copy shares + self._copy_share_to_server(1, 1) + self._copy_share_to_server(2, 1) + # Remove server 0 + self.g.remove_server(self.g.servers_by_number[0].my_nodeid) + client = self.g.clients[0] + client.DEFAULT_ENCODING_PARAMETERS['happy'] = 3 + return client + + d.addCallback(_setup) + d.addCallback(lambda client: + client.upload(upload.Data("data" * 10000, convergence=""))) return d + test_problem_layout_comment_187.todo = "this isn't fixed yet" def _set_up_nodes_extra_config(self, clientdir):