291 lines
9.7 KiB
Python
Executable File
291 lines
9.7 KiB
Python
Executable File
#!/usr/bin/env python3
|
|
|
|
import hashlib
|
|
import bisect
|
|
import xxhash
|
|
import numpy as np
|
|
|
|
REPLICATION_FACTOR = 3
|
|
|
|
def hash_str(s):
|
|
xxh = xxhash.xxh64()
|
|
xxh.update(s.encode('ascii'))
|
|
return xxh.hexdigest()
|
|
|
|
def sha256_str(s):
|
|
return hashlib.sha256(s.encode('ascii')).hexdigest()
|
|
|
|
def walk_ring_from_pos(tokens, dcs, start):
|
|
ret = []
|
|
ret_dcs = set()
|
|
delta = 0
|
|
while len(ret) < REPLICATION_FACTOR:
|
|
i = (start + delta) % len(tokens)
|
|
delta = delta + 1
|
|
|
|
(token_k, token_dc, token_node) = tokens[i]
|
|
if token_dc not in ret_dcs:
|
|
ret_dcs |= set([token_dc])
|
|
ret.append(token_node)
|
|
elif len(ret_dcs) == len(dcs) and token_node not in ret:
|
|
ret.append(token_node)
|
|
return ret
|
|
|
|
"""
|
|
def count_tokens_per_node(tokens):
|
|
tokens_of_node = {}
|
|
for _, _, token_node in tokens:
|
|
if token_node not in tokens_of_node:
|
|
tokens_of_node[token_node] = 0
|
|
tokens_of_node[token_node] += 1
|
|
print("#tokens per node:")
|
|
for node, ntok in sorted(list(tokens_of_node.items())):
|
|
print("-", node, ": ", ntok)
|
|
"""
|
|
|
|
def count_partitions_per_node(ring_node_list):
|
|
tokens_of_node = {}
|
|
for nodelist in ring_node_list:
|
|
for node_id in nodelist:
|
|
if node_id not in tokens_of_node:
|
|
tokens_of_node[node_id] = 0
|
|
tokens_of_node[node_id] += 1
|
|
print("#partitions per node:")
|
|
for node, ntok in sorted(list(tokens_of_node.items())):
|
|
print("-", node, ": ", ntok)
|
|
|
|
|
|
def method1(nodes):
|
|
tokens = []
|
|
dcs = set()
|
|
for (node_id, dc, n_tokens) in nodes:
|
|
dcs |= set([dc])
|
|
for i in range(n_tokens):
|
|
token = hash_str(f"{node_id} {i}")
|
|
tokens.append((token, dc, node_id))
|
|
tokens.sort(key=lambda tok: tok[0])
|
|
|
|
space_of_node = {}
|
|
|
|
def walk_ring(v):
|
|
i = bisect.bisect_left([tok for tok, _, _ in tokens], hash_str(v))
|
|
return walk_ring_from_pos(tokens, dcs, i)
|
|
|
|
ring_node_list = [walk_ring_from_pos(tokens, dcs, i) for i in range(len(tokens))]
|
|
|
|
return walk_ring, ring_node_list
|
|
|
|
|
|
def method2(nodes):
|
|
partition_bits = 10
|
|
partitions = list(range(2**partition_bits))
|
|
def partition_node(i):
|
|
h, hn, hndc = None, None, None
|
|
for (node_id, node_dc, n_tokens) in nodes:
|
|
for tok in range(n_tokens):
|
|
hnode = hash_str(f"partition {i} node {node_id} token {tok}")
|
|
if h is None or hnode < h:
|
|
h = hnode
|
|
hn = node_id
|
|
hndc = node_dc
|
|
return (i, hndc, hn)
|
|
|
|
partition_nodes = [partition_node(i) for i in partitions]
|
|
|
|
dcs = list(set(node_dc for _, node_dc, _ in nodes))
|
|
|
|
|
|
def walk_ring(v):
|
|
# xxh = xxhash.xxh32()
|
|
# xxh.update(v.encode('ascii'))
|
|
# vh = xxh.intdigest()
|
|
# i = vh % (2**partition_bits)
|
|
vh = hashlib.sha256(v.encode('ascii')).digest()
|
|
i = (vh[0]<<8 | vh[1]) % (2**partition_bits)
|
|
return walk_ring_from_pos(partition_nodes, dcs, i)
|
|
|
|
ring_node_list = [walk_ring_from_pos(partition_nodes, dcs, i) for i in range(len(partition_nodes))]
|
|
|
|
return walk_ring, ring_node_list
|
|
|
|
|
|
def method3(nodes):
|
|
partition_bits = 10
|
|
|
|
queues = []
|
|
for (node_id, node_dc, n_tokens) in nodes:
|
|
que = [(i, hash_str(f"{node_id} {i}")) for i in range(2**partition_bits)]
|
|
que.sort(key=lambda x: x[1])
|
|
que = [x[0] for x in que]
|
|
queues.append((node_id, node_dc, n_tokens, que))
|
|
|
|
partitions = [None for _ in range(2**partition_bits)]
|
|
queues.sort(key=lambda x: hash_str(x[0]))
|
|
|
|
# Maglev
|
|
remaining = 2**partition_bits
|
|
while remaining > 0:
|
|
for toktok in range(100):
|
|
for iq in range(len(queues)):
|
|
node_id, node_dc, n_tokens, node_queue = queues[iq]
|
|
if toktok >= n_tokens:
|
|
continue
|
|
for qi, qv in enumerate(node_queue):
|
|
if partitions[qv] == None:
|
|
partitions[qv] = (qv, node_dc, node_id)
|
|
remaining -= 1
|
|
queues[iq] = (node_id, node_dc, n_tokens, node_queue[qi+1:])
|
|
break
|
|
|
|
dcs = list(set(node_dc for _, node_dc, _ in nodes))
|
|
|
|
def walk_ring(v):
|
|
vh = hashlib.sha256(v.encode('ascii')).digest()
|
|
i = (vh[0]<<8 | vh[1]) % (2**partition_bits)
|
|
return walk_ring_from_pos(partitions, dcs, i)
|
|
|
|
ring_node_list = [walk_ring_from_pos(partitions, dcs, i) for i in range(len(partitions))]
|
|
|
|
return walk_ring, ring_node_list
|
|
|
|
|
|
|
|
def method4(nodes):
|
|
partition_bits = 10
|
|
|
|
partitions = [[] for _ in range(2**partition_bits)]
|
|
dcs = list(set(node_dc for _, node_dc, _ in nodes))
|
|
|
|
# Maglev, improved for several replicas on several DCs
|
|
for ri in range(REPLICATION_FACTOR):
|
|
queues = []
|
|
for (node_id, node_dc, n_tokens) in nodes:
|
|
que = [(i, hash_str(f"{node_id} {i}")) for i in range(2**partition_bits)]
|
|
que.sort(key=lambda x: x[1])
|
|
que = [x[0] for x in que]
|
|
queues.append((node_id, node_dc, n_tokens, que))
|
|
|
|
queues.sort(key=lambda x: hash_str("{} {}".format(ri, x[0])))
|
|
|
|
remaining = 2**partition_bits
|
|
while remaining > 0:
|
|
for toktok in range(100):
|
|
for iq in range(len(queues)):
|
|
node_id, node_dc, n_tokens, node_queue = queues[iq]
|
|
if toktok >= n_tokens:
|
|
continue
|
|
for qi, qv in enumerate(node_queue):
|
|
if len(partitions[qv]) != ri:
|
|
continue
|
|
p_dcs = set([x[0] for x in partitions[qv]])
|
|
p_nodes = [x[1] for x in partitions[qv]]
|
|
if node_dc not in p_dcs or (len(p_dcs) == len(dcs) and node_id not in p_nodes):
|
|
partitions[qv].append((node_dc, node_id))
|
|
remaining -= 1
|
|
queues[iq] = (node_id, node_dc, n_tokens, node_queue[qi+1:])
|
|
break
|
|
|
|
def walk_ring(v):
|
|
vh = hashlib.sha256(v.encode('ascii')).digest()
|
|
i = (vh[0]<<8 | vh[1]) % (2**partition_bits)
|
|
assert len(set([node_dc for node_dc, _ in partitions[i]])) == min(REPLICATION_FACTOR, len(dcs))
|
|
return [node_id for _, node_id in partitions[i]]
|
|
|
|
ring_node_list = [[node_id for _, node_id in p] for p in partitions]
|
|
|
|
return walk_ring, ring_node_list
|
|
|
|
def evaluate_method(method, nodes):
|
|
walk_ring, ring_node_list = method(nodes)
|
|
print("Ring length:", len(ring_node_list))
|
|
count_partitions_per_node(ring_node_list)
|
|
|
|
print("Number of data items per node (100000 simulation):")
|
|
node_data_counts = {}
|
|
for i in range(100000):
|
|
inodes = walk_ring(f"{i}")
|
|
for n in inodes:
|
|
if n not in node_data_counts:
|
|
node_data_counts[n] = 0
|
|
node_data_counts[n] += 1
|
|
for n, v in sorted(list(node_data_counts.items())):
|
|
print("-", n, ": ", v)
|
|
|
|
dclist_per_ntok = {}
|
|
for node_id, _, ntok in nodes:
|
|
if ntok not in dclist_per_ntok:
|
|
dclist_per_ntok[ntok] = []
|
|
dclist_per_ntok[ntok].append(node_data_counts[node_id])
|
|
list_normalized = []
|
|
for ntok, dclist in dclist_per_ntok.items():
|
|
avg = sum(dclist)/len(dclist)
|
|
for v in dclist:
|
|
list_normalized.append(v / avg)
|
|
print("variance wrt. same-ntok mean:", "%.2f%%"%(np.var(list_normalized)*100))
|
|
|
|
num_changes_sum = [0, 0, 0, 0]
|
|
for n in nodes:
|
|
nodes2 = [nn for nn in nodes if nn != n]
|
|
_, ring_node_list_2 = method(nodes2)
|
|
if len(ring_node_list_2) != len(ring_node_list):
|
|
continue
|
|
num_changes = [0, 0, 0, 0]
|
|
for (ns1, ns2) in zip(ring_node_list, ring_node_list_2):
|
|
changes = sum(1 for x in ns1 if x not in ns2)
|
|
num_changes[changes] += 1
|
|
for i, v in enumerate(num_changes):
|
|
num_changes_sum[i] += v / len(ring_node_list)
|
|
print("removing", n[1], n[0], ":", " ".join(["%.2f%%"%(x*100/len(ring_node_list)) for x in num_changes]))
|
|
print("1-node removal: partitions moved on 0/1/2/3 nodes: ", " ".join(["%.2f%%"%(x*100/len(nodes)) for x in num_changes_sum]))
|
|
|
|
|
|
if __name__ == "__main__":
|
|
print("------")
|
|
print("method 1 (standard ring)")
|
|
nodes = [('digitale', 'atuin', 64),
|
|
('drosera', 'atuin', 64),
|
|
('datura', 'atuin', 64),
|
|
('io', 'jupiter', 128)]
|
|
nodes2 = [('digitale', 'atuin', 64),
|
|
('drosera', 'atuin', 64),
|
|
('datura', 'atuin', 64),
|
|
('io', 'jupiter', 128),
|
|
('isou', 'jupiter', 64),
|
|
('mini', 'grog', 32),
|
|
('mixi', 'grog', 32),
|
|
('moxi', 'grog', 32),
|
|
('modi', 'grog', 32),
|
|
('geant', 'grisou', 128),
|
|
('gipsie', 'grisou', 128),
|
|
]
|
|
evaluate_method(method1, nodes2)
|
|
|
|
print("------")
|
|
print("method 2 (custom ring)")
|
|
nodes = [('digitale', 'atuin', 1),
|
|
('drosera', 'atuin', 1),
|
|
('datura', 'atuin', 1),
|
|
('io', 'jupiter', 2)]
|
|
nodes2 = [('digitale', 'atuin', 2),
|
|
('drosera', 'atuin', 2),
|
|
('datura', 'atuin', 2),
|
|
('io', 'jupiter', 4),
|
|
('isou', 'jupiter', 2),
|
|
('mini', 'grog', 1),
|
|
('mixi', 'grog', 1),
|
|
('moxi', 'grog', 1),
|
|
('modi', 'grog', 1),
|
|
('geant', 'grisou', 4),
|
|
('gipsie', 'grisou', 4),
|
|
]
|
|
evaluate_method(method2, nodes2)
|
|
|
|
print("------")
|
|
print("method 3 (maglev)")
|
|
evaluate_method(method3, nodes2)
|
|
|
|
|
|
print("------")
|
|
print("method 4 (maglev, multi-dc twist)")
|
|
evaluate_method(method4, nodes2)
|