blob: 9bb8116c434e258ecb6e0f12b3e9ed19364ea723 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
# frozen_string_literal: true
require 'spec_helper'
RSpec.describe Gitlab::Database::LoadBalancing::HostList do
let(:db_host) { ActiveRecord::Base.connection_pool.db_config.host }
let(:load_balancer) do
Gitlab::Database::LoadBalancing::LoadBalancer.new(
Gitlab::Database::LoadBalancing::Configuration.new(ActiveRecord::Base)
)
end
let(:host_count) { 2 }
let(:hosts) { Array.new(host_count) { Gitlab::Database::LoadBalancing::Host.new(db_host, load_balancer, port: 5432) } }
let(:host_list) { described_class.new(hosts) }
before do
# each call generate a new replica pool
allow(load_balancer).to receive(:create_replica_connection_pool) do
double(:replica_connection_pool)
end
end
describe '#initialize' do
it 'sets metrics for current number of hosts and current index' do
host_list
expect_metrics(2)
end
end
describe '#length' do
it 'returns the number of hosts in the list' do
expect(host_list.length).to eq(2)
end
end
describe '#host_names_and_ports' do
context 'with ports' do
it 'returns the host names of all hosts' do
hosts = [
[db_host, 5432],
[db_host, 5432]
]
expect(host_list.host_names_and_ports).to eq(hosts)
end
end
context 'without ports' do
let(:hosts) { Array.new(2) { Gitlab::Database::LoadBalancing::Host.new(db_host, load_balancer) } }
it 'returns the host names of all hosts' do
hosts = [
[db_host, nil],
[db_host, nil]
]
expect(host_list.host_names_and_ports).to eq(hosts)
end
end
end
describe '#hosts' do
it 'returns a copy of the host' do
first = host_list.hosts
expect(host_list.hosts).to eq(first)
expect(host_list.hosts.object_id).not_to eq(first.object_id)
end
end
describe '#hosts=' do
it 'updates the list of hosts to use' do
host_list.hosts = [
Gitlab::Database::LoadBalancing::Host.new('foo', load_balancer)
]
expect(host_list.length).to eq(1)
expect(host_list.hosts[0].host).to eq('foo')
expect_metrics(1)
end
end
describe '#next' do
it 'returns a host' do
expect(host_list.next)
.to be_an_instance_of(Gitlab::Database::LoadBalancing::Host)
end
it 'cycles through all available hosts' do
expect(host_list.next).to eq(host_list.hosts[0])
expect_metrics(2)
expect(host_list.next).to eq(host_list.hosts[1])
expect_metrics(2)
expect(host_list.next).to eq(host_list.hosts[0])
expect_metrics(2)
end
it 'skips hosts that are offline' do
allow(host_list.hosts[0]).to receive(:online?).and_return(false)
expect(host_list.next).to eq(host_list.hosts[1])
expect_metrics(2)
end
it 'returns nil if no hosts are online' do
host_list.hosts.each do |host|
allow(host).to receive(:online?).and_return(false)
end
expect(host_list.next).to be_nil
expect_metrics(2)
end
it 'returns nil if no hosts are available' do
expect(described_class.new.next).to be_nil
end
end
describe '#shuffle' do
let(:host_count) { 3 }
it 'randomizes the list' do
2.times do
all_hosts = host_list.hosts
host_list.shuffle
expect(host_list.length).to eq(host_count)
expect(host_list.hosts).to contain_exactly(*all_hosts)
end
end
end
def expect_metrics(hosts)
expect(Gitlab::Metrics.registry.get(:db_load_balancing_hosts).get({})).to eq(hosts)
end
end
|
