def move_single_node_test(self):
""" Test moving a node in a single-node cluster (#4200) """
cluster = self.cluster
# Create an unbalanced ring
cluster.populate(1, tokens=[0]).start()
node1 = cluster.nodelist()[0]
time.sleep(0.2)
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 1)
self.create_cf(cursor, 'cf', columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
cluster.flush()
node1.move(2**25)
time.sleep(1)
cluster.cleanup()
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
def readrepair_test(self):
cluster = self.cluster
cluster.set_configuration_options(values={ 'hinted_handoff_enabled' : False})
if DISABLE_VNODES:
cluster.populate(2).start()
else:
tokens = cluster.balanced_tokens(2)
cluster.populate(2, tokens=tokens).start()
[node1, node2] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
create_c1c2_table(self, cursor, read_repair=1.0)
node2.stop(wait_other_notice=True)
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
node2.start(wait_other_notice=True)
# query everything to cause RR
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
node1.stop(wait_other_notice=True)
# Check node2 for all the keys that should have been repaired
cursor = self.patient_cql_connection(node2, keyspace='ks')
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
def hintedhandoff_test(self):
cluster = self.cluster
if DISABLE_VNODES:
cluster.populate(2).start()
else:
tokens = cluster.balanced_tokens(2)
cluster.populate(2, tokens=tokens).start()
[node1, node2] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
create_c1c2_table(self, cursor)
node2.stop(wait_other_notice=True)
for n in xrange(0, 100):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
log_mark = node1.mark_log()
node2.start()
node1.watch_log_for(["Finished hinted"],
from_mark=log_mark,
timeout=120)
node1.stop(wait_other_notice=True)
# Check node2 for all the keys that should have been delivered via HH
cursor = self.patient_cql_connection(node2, keyspace='ks')
for n in xrange(0, 100):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
def hintedhandoff_test(self):
cluster = self.cluster
if DISABLE_VNODES:
cluster.populate(2).start()
else:
tokens = cluster.balanced_tokens(2)
cluster.populate(2, tokens=tokens).start()
[node1, node2] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
create_c1c2_table(self, cursor)
node2.stop(wait_other_notice=True)
for n in xrange(0, 100):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
log_mark = node1.mark_log()
node2.start()
node1.watch_log_for(["Finished hinted"], from_mark=log_mark, timeout=90)
node1.stop(wait_other_notice=True)
# Check node2 for all the keys that should have been delivered via HH
cursor = self.patient_cql_connection(node2, keyspace='ks')
for n in xrange(0, 100):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
def quorum_available_during_failure_test(self):
CL = ConsistencyLevel.QUORUM
RF = 3
debug("Creating a ring")
cluster = self.cluster
if DISABLE_VNODES:
cluster.populate(3).start()
else:
tokens = cluster.balanced_tokens(3)
cluster.populate(3, tokens=tokens).start()
[node1, node2, node3] = cluster.nodelist()
cluster.start()
debug("Set to talk to node 2")
cursor = self.patient_cql_connection(node2)
self.create_ks(cursor, 'ks', RF)
create_c1c2_table(self, cursor)
debug("Generating some data")
for n in xrange(100):
insert_c1c2(cursor, n, CL)
debug("Taking down node1")
node1.stop(wait_other_notice=True)
debug("Reading back data.")
for n in xrange(100):
query_c1c2(cursor, n, CL)
def check_rows_on_node(self,
node_to_check,
rows,
found=[],
missings=[],
restart=True):
stopped_nodes = []
for node in self.cluster.nodes.values():
if node.is_running() and node is not node_to_check:
stopped_nodes.append(node)
node.stop(wait_other_notice=True)
cursor = self.patient_cql_connection(node_to_check, 'ks')
result = cursor.execute("SELECT * FROM cf LIMIT %d" % (rows * 2))
assert len(result) == rows, len(result)
for k in found:
query_c1c2(cursor, k, ConsistencyLevel.ONE)
for k in missings:
query = SimpleStatement("SELECT c1, c2 FROM cf WHERE key='k%d'" %
k,
consistency_level=ConsistencyLevel.ONE)
res = cursor.execute(query)
assert len(filter(lambda x: len(x) != 0, res)) == 0, res
if restart:
for node in stopped_nodes:
node.start(wait_other_notice=True)
def move_single_node_test(self):
""" Test moving a node in a single-node cluster (#4200) """
cluster = self.cluster
# Create an unbalanced ring
cluster.populate(1, tokens=[0]).start()
node1 = cluster.nodelist()[0]
time.sleep(0.2)
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 1)
self.create_cf(cursor, 'cf', columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
cluster.flush()
node1.move(2**25)
time.sleep(1)
cluster.cleanup()
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
def readrepair_test(self):
cluster = self.cluster
cluster.set_configuration_options(
values={'hinted_handoff_enabled': False})
if DISABLE_VNODES:
cluster.populate(2).start()
else:
tokens = cluster.balanced_tokens(2)
cluster.populate(2, tokens=tokens).start()
[node1, node2] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
create_c1c2_table(self, cursor, read_repair=1.0)
node2.stop(wait_other_notice=True)
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
node2.start(wait_other_notice=True)
# query everything to cause RR
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
node1.stop(wait_other_notice=True)
# Check node2 for all the keys that should have been repaired
cursor = self.patient_cql_connection(node2, keyspace='ks')
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
def quorum_available_during_failure_test(self):
CL = ConsistencyLevel.QUORUM
RF = 3
debug("Creating a ring")
cluster = self.cluster
if DISABLE_VNODES:
cluster.populate(3).start()
else:
tokens = cluster.balanced_tokens(3)
cluster.populate(3, tokens=tokens).start()
[node1, node2, node3] = cluster.nodelist()
cluster.start()
debug("Set to talk to node 2")
cursor = self.patient_cql_connection(node2)
self.create_ks(cursor, 'ks', RF)
create_c1c2_table(self, cursor)
debug("Generating some data")
for n in xrange(100):
insert_c1c2(cursor, n, CL)
debug("Taking down node1")
node1.stop(wait_other_notice=True)
debug("Reading back data.")
for n in xrange(100):
query_c1c2(cursor, n, CL)
def quorum_quorum_test(self):
session, session2 = self.cl_cl_prepare(ConsistencyLevel.QUORUM, ConsistencyLevel.QUORUM)
#Stop a node and retest
self.cluster.nodelist()[2].stop()
for n in xrange(0, 100):
insert_c1c2(session, n, ConsistencyLevel.QUORUM)
query_c1c2(session2, n, ConsistencyLevel.QUORUM)
self.cluster.nodelist()[1].stop()
assert_unavailable(insert_c1c2, session, 100, ConsistencyLevel.QUORUM)
def quorum_quorum_test(self):
session, session2 = self.cl_cl_prepare(ConsistencyLevel.QUORUM,
ConsistencyLevel.QUORUM)
#Stop a node and retest
self.cluster.nodelist()[2].stop()
for n in xrange(0, 100):
insert_c1c2(session, n, ConsistencyLevel.QUORUM)
query_c1c2(session2, n, ConsistencyLevel.QUORUM)
self.cluster.nodelist()[1].stop()
assert_unavailable(insert_c1c2, session, 100, ConsistencyLevel.QUORUM)
def all_one_test(self):
session, session2 = self.cl_cl_prepare(ConsistencyLevel.ALL, ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[2].stop()
assert_unavailable(insert_c1c2, session, 100, ConsistencyLevel.ALL)
for n in xrange(0, 100):
query_c1c2(session2, n, ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[1].stop()
assert_unavailable(insert_c1c2, session, 100, ConsistencyLevel.ALL)
for n in xrange(0, 100):
query_c1c2(session2, n, ConsistencyLevel.ONE)
def one_one_test(self):
session, session2 = self.cl_cl_prepare(ConsistencyLevel.ONE, ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[2].stop()
for n in xrange(0, 100):
insert_c1c2(session, n, ConsistencyLevel.ONE)
query_c1c2(session2, n, ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[1].stop()
for n in xrange(0, 100):
insert_c1c2(session, n, ConsistencyLevel.ONE)
query_c1c2(session2, n, ConsistencyLevel.ONE)
def one_one_test(self):
session, session2 = self.cl_cl_prepare(ConsistencyLevel.ONE,
ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[2].stop()
for n in xrange(0, 100):
insert_c1c2(session, n, ConsistencyLevel.ONE)
query_c1c2(session2, n, ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[1].stop()
for n in xrange(0, 100):
insert_c1c2(session, n, ConsistencyLevel.ONE)
query_c1c2(session2, n, ConsistencyLevel.ONE)
def all_one_test(self):
session, session2 = self.cl_cl_prepare(ConsistencyLevel.ALL,
ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[2].stop()
assert_unavailable(insert_c1c2, session, 100, ConsistencyLevel.ALL)
for n in xrange(0, 100):
query_c1c2(session2, n, ConsistencyLevel.ONE)
#Stop a node and retest
self.cluster.nodelist()[1].stop()
assert_unavailable(insert_c1c2, session, 100, ConsistencyLevel.ALL)
for n in xrange(0, 100):
query_c1c2(session2, n, ConsistencyLevel.ONE)
def non_local_read_test(self):
""" This test reads from a coordinator we know has no copy of the data """
cluster = self.cluster
cluster.populate(3).start()
[node1, node2, node3] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
create_c1c2_table(self, cursor)
# insert and get at CL.QUORUM (since RF=2, node1 won't have all key locally)
for n in xrange(0, 1000):
tools.insert_c1c2(cursor, n, ConsistencyLevel.QUORUM)
tools.query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
def cl_cl_prepare(self, write_cl, read_cl):
cluster = self.cluster
cluster.populate(3).start()
node1, node2, node3 = cluster.nodelist()
session = self.patient_cql_connection(node1)
self.create_ks(session, 'ks', 3)
create_c1c2_table(self, session)
session2 = self.patient_cql_connection(node2, 'ks')
# insert and get at CL.QUORUM
for n in xrange(0, 100):
insert_c1c2(session, n, write_cl)
query_c1c2(session2, n, read_cl)
return session, session2
def cl_cl_prepare(self, write_cl, read_cl):
cluster = self.cluster
cluster.populate(3).start()
node1, node2, node3 = cluster.nodelist()
session = self.patient_cql_connection(node1)
self.create_ks(session, 'ks', 3)
create_c1c2_table(self, session)
session2 = self.patient_cql_connection(node2, 'ks')
# insert and get at CL.QUORUM
for n in xrange(0, 100):
insert_c1c2(session, n, write_cl)
query_c1c2(session2, n, read_cl)
return session, session2
def consistent_reads_after_bootstrap_test(self):
debug("Creating a ring")
cluster = self.cluster
cluster.set_configuration_options(values={ 'hinted_handoff_enabled' : False, 'write_request_timeout_in_ms' : 60000, 'read_request_timeout_in_ms' : 60000, 'dynamic_snitch_badness_threshold' : 0.0}, batch_commitlog=True)
cluster.populate(2).start()
[node1, node2] = cluster.nodelist()
cluster.start()
debug("Set to talk to node 2")
n2cursor = self.patient_cql_connection(node2)
self.create_ks(n2cursor, 'ks', 2)
create_c1c2_table(self, n2cursor)
debug("Generating some data for all nodes")
for n in xrange(10,20):
insert_c1c2(n2cursor, n, ConsistencyLevel.ALL)
node1.flush()
debug("Taking down node1")
node1.stop(wait_other_notice=True)
debug("Writing data to only node2")
for n in xrange(30,1000):
insert_c1c2(n2cursor, n, ConsistencyLevel.ONE)
node2.flush()
debug("Restart node1")
node1.start(wait_other_notice=True)
debug("Boostraping node3")
node3 = new_node(cluster)
node3.start()
n3cursor = self.patient_cql_connection(node3)
n3cursor.execute("USE ks");
debug("Checking that no data was lost")
for n in xrange(10,20):
query_c1c2(n3cursor, n, ConsistencyLevel.ALL)
for n in xrange(30,1000):
query_c1c2(n3cursor, n, ConsistencyLevel.ALL)
def movement_test(self):
cluster = self.cluster
# Create an unbalanced ring
cluster.populate(3, tokens=[0, 2**48, 2**62]).start()
[node1, node2, node3] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 1)
self.create_cf(cursor, 'cf', columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
cluster.flush()
# Move nodes to balance the cluster
balancing_tokens = cluster.balanced_tokens(3)
escformat = '\\%s'
if cluster.version() >= '2.1':
escformat = '%s'
node1.move(escformat %
balancing_tokens[0]) # can't assume 0 is balanced with m3p
node2.move(escformat % balancing_tokens[1])
node3.move(escformat % balancing_tokens[2])
time.sleep(1)
cluster.cleanup()
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
# Now the load should be basically even
sizes = [node.data_size() for node in [node1, node2, node3]]
assert_almost_equal(sizes[0], sizes[1])
assert_almost_equal(sizes[0], sizes[2])
assert_almost_equal(sizes[1], sizes[2])
def check_rows_on_node(self, node_to_check, rows, found=[], missings=[], restart=True):
stopped_nodes = []
for node in self.cluster.nodes.values():
if node.is_running() and node is not node_to_check:
stopped_nodes.append(node)
node.stop(wait_other_notice=True)
cursor = self.patient_cql_connection(node_to_check, 'ks')
result = cursor.execute("SELECT * FROM cf LIMIT %d" % (rows * 2))
assert len(result) == rows, len(result)
for k in found:
query_c1c2(cursor, k, ConsistencyLevel.ONE)
for k in missings:
query = SimpleStatement("SELECT c1, c2 FROM cf WHERE key='k%d'" % k, consistency_level=ConsistencyLevel.ONE)
res = cursor.execute(query)
assert len(filter(lambda x: len(x) != 0, res)) == 0, res
if restart:
for node in stopped_nodes:
node.start(wait_other_notice=True)
def movement_test(self):
cluster = self.cluster
# Create an unbalanced ring
cluster.populate(3, tokens=[0, 2**48, 2**62]).start()
[node1, node2, node3] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 1)
self.create_cf(cursor, 'cf', columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.ONE)
cluster.flush()
# Move nodes to balance the cluster
balancing_tokens = cluster.balanced_tokens(3)
escformat = '\\%s'
if cluster.version() >= '2.1':
escformat = '%s'
node1.move(escformat % balancing_tokens[0]) # can't assume 0 is balanced with m3p
node2.move(escformat % balancing_tokens[1])
node3.move(escformat % balancing_tokens[2])
time.sleep(1)
cluster.cleanup()
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.ONE)
# Now the load should be basically even
sizes = [ node.data_size() for node in [node1, node2, node3] ]
assert_almost_equal(sizes[0], sizes[1])
assert_almost_equal(sizes[0], sizes[2])
assert_almost_equal(sizes[1], sizes[2])
def simple_bootstrap_test(self):
cluster = self.cluster
tokens = cluster.balanced_tokens(2)
keys = 10000
# Create a single node cluster
cluster.populate(1, tokens=[tokens[0]]).start(wait_other_notice=True)
node1 = cluster.nodes["node1"]
session = self.patient_cql_connection(node1)
self.create_ks(session, 'ks', 1)
self.create_cf(session, 'cf', columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, keys):
insert_c1c2(session, n, ConsistencyLevel.ONE)
node1.flush()
initial_size = node1.data_size()
# Reads inserted data all during the boostrap process. We shouldn't
# get any error
reader = self.go(lambda _: query_c1c2(
session, random.randint(0, keys - 1), ConsistencyLevel.ONE))
# Boostraping a new node
node2 = new_node(cluster, token=tokens[1])
node2.start()
node2.watch_log_for("Listening for thrift clients...")
reader.check()
node1.cleanup()
time.sleep(.5)
reader.check()
size1 = node1.data_size()
size2 = node2.data_size()
assert_almost_equal(size1, size2, error=0.3)
assert_almost_equal(initial_size, 2 * size1)
def simple_bootstrap_test(self):
cluster = self.cluster
tokens = cluster.balanced_tokens(2)
keys = 10000
# Create a single node cluster
cluster.populate(1, tokens=[tokens[0]]).start(wait_other_notice=True)
node1 = cluster.nodes["node1"]
session = self.patient_cql_connection(node1)
self.create_ks(session, 'ks', 1)
self.create_cf(session, 'cf', columns={ 'c1' : 'text', 'c2' : 'text' })
for n in xrange(0, keys):
insert_c1c2(session, n, ConsistencyLevel.ONE)
node1.flush()
initial_size = node1.data_size()
# Reads inserted data all during the boostrap process. We shouldn't
# get any error
reader = self.go(lambda _: query_c1c2(session, random.randint(0, keys-1), ConsistencyLevel.ONE))
# Boostraping a new node
node2 = new_node(cluster, token=tokens[1])
node2.start()
node2.watch_log_for("Listening for thrift clients...")
reader.check()
node1.cleanup()
time.sleep(.5)
reader.check()
size1 = node1.data_size()
size2 = node2.data_size()
assert_almost_equal(size1, size2, error=0.3)
assert_almost_equal(initial_size, 2 * size1)
def decomission_test(self):
cluster = self.cluster
tokens = cluster.balanced_tokens(4)
cluster.populate(4, tokens=tokens).start()
[node1, node2, node3, node4] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
self.create_cf(cursor, 'cf',columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.QUORUM)
cluster.flush()
sizes = [ node.data_size() for node in cluster.nodelist() if node.is_running()]
init_size = sizes[0]
assert_almost_equal(*sizes)
time.sleep(.5)
node4.decommission()
node4.stop()
cluster.cleanup()
time.sleep(.5)
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
sizes = [ node.data_size() for node in cluster.nodelist() if node.is_running() ]
three_node_sizes = sizes
assert_almost_equal(sizes[0], sizes[1])
assert_almost_equal((2.0/3.0) * sizes[0], sizes[2])
assert_almost_equal(sizes[2], init_size)
if cluster.version() <= '1.2':
node3.stop(wait_other_notice=True)
node1.removeToken(tokens[2])
time.sleep(.5)
cluster.cleanup()
time.sleep(.5)
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
sizes = [ node.data_size() for node in cluster.nodelist() if node.is_running() ]
assert_almost_equal(*sizes)
assert_almost_equal(sizes[0], 2 * init_size)
node5 = new_node(cluster, token=(tokens[2]+1)).start()
time.sleep(.5)
cluster.cleanup()
time.sleep(.5)
cluster.compact()
time.sleep(.5)
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
sizes = [ node.data_size() for node in cluster.nodelist() if node.is_running() ]
# We should be back to the earlir 3 nodes situation
for i in xrange(0, len(sizes)):
assert_almost_equal(sizes[i], three_node_sizes[i])
def decomission_test(self):
cluster = self.cluster
tokens = cluster.balanced_tokens(4)
cluster.populate(4, tokens=tokens).start()
[node1, node2, node3, node4] = cluster.nodelist()
cursor = self.patient_cql_connection(node1)
self.create_ks(cursor, 'ks', 2)
self.create_cf(cursor, 'cf', columns={'c1': 'text', 'c2': 'text'})
for n in xrange(0, 10000):
insert_c1c2(cursor, n, ConsistencyLevel.QUORUM)
cluster.flush()
sizes = [
node.data_size() for node in cluster.nodelist()
if node.is_running()
]
init_size = sizes[0]
assert_almost_equal(*sizes)
time.sleep(.5)
node4.decommission()
node4.stop()
cluster.cleanup()
time.sleep(.5)
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
sizes = [
node.data_size() for node in cluster.nodelist()
if node.is_running()
]
three_node_sizes = sizes
assert_almost_equal(sizes[0], sizes[1])
assert_almost_equal((2.0 / 3.0) * sizes[0], sizes[2])
assert_almost_equal(sizes[2], init_size)
if cluster.version() <= '1.2':
node3.stop(wait_other_notice=True)
node1.removeToken(tokens[2])
time.sleep(.5)
cluster.cleanup()
time.sleep(.5)
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
sizes = [
node.data_size() for node in cluster.nodelist()
if node.is_running()
]
assert_almost_equal(*sizes)
assert_almost_equal(sizes[0], 2 * init_size)
node5 = new_node(cluster, token=(tokens[2] + 1)).start()
time.sleep(.5)
cluster.cleanup()
time.sleep(.5)
cluster.compact()
time.sleep(.5)
# Check we can get all the keys
for n in xrange(0, 10000):
query_c1c2(cursor, n, ConsistencyLevel.QUORUM)
sizes = [
node.data_size() for node in cluster.nodelist()
if node.is_running()
]
# We should be back to the earlir 3 nodes situation
for i in xrange(0, len(sizes)):
assert_almost_equal(sizes[i], three_node_sizes[i])
