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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
# frozen_string_literal: true
require 'spec_helper'
RSpec.describe Gitlab::Database::ConcurrentReindex, '#execute' do
subject { described_class.new(index_name, logger: logger) }
let(:table_name) { '_test_reindex_table' }
let(:column_name) { '_test_column' }
let(:index_name) { '_test_reindex_index' }
let(:logger) { double('logger', debug: nil, info: nil, error: nil ) }
let(:connection) { ActiveRecord::Base.connection }
before do
connection.execute(<<~SQL)
CREATE TABLE #{table_name} (
id serial NOT NULL PRIMARY KEY,
#{column_name} integer NOT NULL);
CREATE INDEX #{index_name} ON #{table_name} (#{column_name});
SQL
end
context 'when the index does not exist' do
before do
connection.execute(<<~SQL)
DROP INDEX #{index_name}
SQL
end
it 'raises an error' do
expect { subject.execute }.to raise_error(described_class::ReindexError, /does not exist/)
end
end
context 'when the index is unique' do
before do
connection.execute(<<~SQL)
DROP INDEX #{index_name};
CREATE UNIQUE INDEX #{index_name} ON #{table_name} (#{column_name})
SQL
end
it 'raises an error' do
expect do
subject.execute
end.to raise_error(described_class::ReindexError, /UNIQUE indexes are currently not supported/)
end
end
context 'replacing the original index with a rebuilt copy' do
let(:replacement_name) { 'tmp_reindex__test_reindex_index' }
let(:replaced_name) { 'old_reindex__test_reindex_index' }
let(:create_index) { "CREATE INDEX CONCURRENTLY #{replacement_name} ON public.#{table_name} USING btree (#{column_name})" }
let(:drop_index) { "DROP INDEX CONCURRENTLY IF EXISTS #{replacement_name}" }
let!(:original_index) { find_index_create_statement }
before do
allow(subject).to receive(:connection).and_return(connection)
allow(subject).to receive(:disable_statement_timeout).and_yield
end
it 'replaces the existing index with an identical index' do
expect(subject).to receive(:disable_statement_timeout).exactly(3).times.and_yield
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
expect(instance).to receive(:run).with(raise_on_exhaustion: true).and_yield
end
expect_to_execute_in_order("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
expect_to_execute_in_order("ALTER INDEX #{replacement_name} RENAME TO #{index_name}")
expect_to_execute_in_order("ALTER INDEX #{replaced_name} RENAME TO #{replacement_name}")
expect_to_execute_concurrently_in_order(drop_index)
subject.execute
check_index_exists
end
context 'when a dangling index is left from a previous run' do
before do
connection.execute("CREATE INDEX #{replacement_name} ON #{table_name} (#{column_name})")
end
it 'replaces the existing index with an identical index' do
expect(subject).to receive(:disable_statement_timeout).exactly(3).times.and_yield
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
expect(instance).to receive(:run).with(raise_on_exhaustion: true).and_yield
end
expect_to_execute_in_order("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
expect_to_execute_in_order("ALTER INDEX #{replacement_name} RENAME TO #{index_name}")
expect_to_execute_in_order("ALTER INDEX #{replaced_name} RENAME TO #{replacement_name}")
expect_to_execute_concurrently_in_order(drop_index)
subject.execute
check_index_exists
end
end
context 'when it fails to create the replacement index' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect(connection).to receive(:execute).with(create_index).ordered
.and_raise(ActiveRecord::ConnectionTimeoutError, 'connect timeout')
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /connect timeout/)
check_index_exists
end
end
context 'when the replacement index is not valid' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect(subject).to receive(:replacement_index_valid?).and_return(false)
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /replacement index was created as INVALID/)
check_index_exists
end
end
context 'when a database error occurs while swapping the indexes' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
expect(instance).to receive(:run).with(raise_on_exhaustion: true).and_yield
end
expect(connection).to receive(:execute).ordered
.with("ALTER INDEX #{index_name} RENAME TO #{replaced_name}")
.and_raise(ActiveRecord::ConnectionTimeoutError, 'connect timeout')
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /connect timeout/)
check_index_exists
end
end
context 'when with_lock_retries fails to acquire the lock' do
it 'safely cleans up and signals the error' do
expect_to_execute_concurrently_in_order(drop_index)
expect_to_execute_concurrently_in_order(create_index)
expect_next_instance_of(::Gitlab::Database::WithLockRetries) do |instance|
expect(instance).to receive(:run).with(raise_on_exhaustion: true)
.and_raise(::Gitlab::Database::WithLockRetries::AttemptsExhaustedError, 'exhausted')
end
expect_to_execute_concurrently_in_order(drop_index)
expect { subject.execute }.to raise_error(described_class::ReindexError, /exhausted/)
check_index_exists
end
end
end
def expect_to_execute_concurrently_in_order(sql)
# Indexes cannot be created CONCURRENTLY in a transaction. Since the tests are wrapped in transactions,
# verify the original call but pass through the non-concurrent form.
expect(connection).to receive(:execute).with(sql).ordered.and_wrap_original do |method, sql|
method.call(sql.sub(/CONCURRENTLY/, ''))
end
end
def expect_to_execute_in_order(sql)
expect(connection).to receive(:execute).with(sql).ordered.and_call_original
end
def find_index_create_statement
ActiveRecord::Base.connection.select_value(<<~SQL)
SELECT indexdef
FROM pg_indexes
WHERE schemaname = 'public'
AND indexname = #{ActiveRecord::Base.connection.quote(index_name)}
SQL
end
def check_index_exists
expect(find_index_create_statement).to eq(original_index)
end
end
|