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# frozen_string_literal: true
require 'spec_helper'
RSpec.describe Gitlab::Database::LoadBalancing::Setup do
describe '#setup' do
it 'sets up the load balancer' do
setup = described_class.new(ActiveRecord::Base)
expect(setup).to receive(:configure_connection)
expect(setup).to receive(:setup_connection_proxy)
expect(setup).to receive(:setup_service_discovery)
setup.setup
end
end
describe '#configure_connection' do
it 'configures pool, prepared statements and reconnects to the database' do
config = double(
:config,
configuration_hash: { host: 'localhost', pool: 2, prepared_statements: true },
env_name: 'test',
name: 'main'
)
model = double(:model, connection_db_config: config)
expect(ActiveRecord::DatabaseConfigurations::HashConfig)
.to receive(:new)
.with('test', 'main', {
host: 'localhost',
prepared_statements: false,
pool: Gitlab::Database.default_pool_size
})
.and_call_original
# HashConfig doesn't implement its own #==, so we can't directly compare
# the expected value with a pre-defined one.
expect(model)
.to receive(:establish_connection)
.with(an_instance_of(ActiveRecord::DatabaseConfigurations::HashConfig))
described_class.new(model).configure_connection
end
end
describe '#setup_connection_proxy' do
it 'sets up the load balancer' do
model = Class.new(ActiveRecord::Base)
setup = described_class.new(model)
config = Gitlab::Database::LoadBalancing::Configuration.new(model)
lb = instance_spy(Gitlab::Database::LoadBalancing::LoadBalancer)
allow(lb).to receive(:configuration).and_return(config)
expect(Gitlab::Database::LoadBalancing::LoadBalancer)
.to receive(:new)
.with(setup.configuration)
.and_return(lb)
setup.setup_connection_proxy
expect(model.load_balancer).to eq(lb)
expect(model.sticking)
.to be_an_instance_of(Gitlab::Database::LoadBalancing::Sticking)
end
end
describe '#setup_service_discovery' do
context 'when service discovery is disabled' do
it 'does nothing' do
expect(Gitlab::Database::LoadBalancing::ServiceDiscovery)
.not_to receive(:new)
described_class.new(ActiveRecord::Base).setup_service_discovery
end
end
context 'when service discovery is enabled' do
it 'immediately performs service discovery' do
model = ActiveRecord::Base
setup = described_class.new(model)
sv = instance_spy(Gitlab::Database::LoadBalancing::ServiceDiscovery)
allow(setup.configuration)
.to receive(:service_discovery_enabled?)
.and_return(true)
allow(Gitlab::Database::LoadBalancing::ServiceDiscovery)
.to receive(:new)
.with(setup.load_balancer, setup.configuration.service_discovery)
.and_return(sv)
expect(sv).to receive(:perform_service_discovery)
expect(sv).not_to receive(:start)
setup.setup_service_discovery
end
it 'starts service discovery if needed' do
model = ActiveRecord::Base
setup = described_class.new(model, start_service_discovery: true)
sv = instance_spy(Gitlab::Database::LoadBalancing::ServiceDiscovery)
allow(setup.configuration)
.to receive(:service_discovery_enabled?)
.and_return(true)
allow(Gitlab::Database::LoadBalancing::ServiceDiscovery)
.to receive(:new)
.with(setup.load_balancer, setup.configuration.service_discovery)
.and_return(sv)
expect(sv).to receive(:perform_service_discovery)
expect(sv).to receive(:start)
setup.setup_service_discovery
end
end
end
context 'uses correct base models', :reestablished_active_record_base do
using RSpec::Parameterized::TableSyntax
where do
{
"it picks a dedicated CI connection" => {
env_GITLAB_LOAD_BALANCING_REUSE_PRIMARY_ci: nil,
request_store_active: false,
ff_force_no_sharing_primary_model: false,
expectations: {
main: { read: 'main_replica', write: 'main' },
ci: { read: 'ci_replica', write: 'ci' }
}
},
"with re-use of primary connection it uses CI connection for reads" => {
env_GITLAB_LOAD_BALANCING_REUSE_PRIMARY_ci: 'main',
request_store_active: false,
ff_force_no_sharing_primary_model: false,
expectations: {
main: { read: 'main_replica', write: 'main' },
ci: { read: 'ci_replica', write: 'main' }
}
},
"with re-use and FF force_no_sharing_primary_model enabled with RequestStore it sticks FF and uses CI connection for reads and writes" => {
env_GITLAB_LOAD_BALANCING_REUSE_PRIMARY_ci: 'main',
request_store_active: true,
ff_force_no_sharing_primary_model: true,
expectations: {
main: { read: 'main_replica', write: 'main' },
ci: { read: 'ci_replica', write: 'ci' }
}
},
"with re-use and FF force_no_sharing_primary_model enabled without RequestStore it doesn't use FF and uses CI connection for reads only" => {
env_GITLAB_LOAD_BALANCING_REUSE_PRIMARY_ci: 'main',
request_store_active: true,
ff_force_no_sharing_primary_model: false,
expectations: {
main: { read: 'main_replica', write: 'main' },
ci: { read: 'ci_replica', write: 'main' }
}
}
}
end
with_them do
let(:ci_class) do
Class.new(ActiveRecord::Base) do
def self.name
'Ci::ApplicationRecordTemporary'
end
establish_connection ActiveRecord::DatabaseConfigurations::HashConfig.new(
Rails.env,
'ci',
ActiveRecord::Base.connection_db_config.configuration_hash
)
end
end
let(:models) do
{
main: ActiveRecord::Base,
ci: ci_class
}
end
around do |example|
if request_store_active
Gitlab::WithRequestStore.with_request_store do
stub_feature_flags(force_no_sharing_primary_model: ff_force_no_sharing_primary_model)
RequestStore.clear!
example.run
end
else
example.run
end
end
before do
allow(Gitlab).to receive(:dev_or_test_env?).and_return(false)
# Rewrite `class_attribute` to use rspec mocking and prevent modifying the objects
allow_next_instance_of(described_class) do |setup|
allow(setup).to receive(:configure_connection)
allow(setup).to receive(:setup_class_attribute) do |attribute, value|
allow(setup.model).to receive(attribute) { value }
end
end
stub_env('GITLAB_LOAD_BALANCING_REUSE_PRIMARY_ci', env_GITLAB_LOAD_BALANCING_REUSE_PRIMARY_ci)
# Make load balancer to force init with a dedicated replicas connections
models.each do |_, model|
described_class.new(model).tap do |subject|
subject.configuration.hosts = [subject.configuration.replica_db_config.host]
subject.setup
end
end
end
it 'results match expectations' do
result = models.transform_values do |model|
load_balancer = model.connection.instance_variable_get(:@load_balancer)
{
read: load_balancer.read { |connection| connection.pool.db_config.name },
write: load_balancer.read_write { |connection| connection.pool.db_config.name }
}
end
expect(result).to eq(expectations)
end
it 'does return load_balancer assigned to a given connection' do
models.each do |name, model|
expect(model.load_balancer.name).to eq(name)
expect(model.sticking.instance_variable_get(:@load_balancer)).to eq(model.load_balancer)
end
end
end
end
end
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