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require 'spec_helper'
describe Gitlab::Git::Storage::CircuitBreaker, clean_gitlab_redis_shared_state: true, broken_storage: true do
let(:storage_name) { 'default' }
let(:circuit_breaker) { described_class.new(storage_name, hostname) }
let(:hostname) { Gitlab::Environment.hostname }
let(:cache_key) { "storage_accessible:#{storage_name}:#{hostname}" }
before do
# Override test-settings for the circuitbreaker with something more realistic
# for these specs.
stub_storage_settings('default' => {
'path' => TestEnv.repos_path
},
'broken' => {
'path' => 'tmp/tests/non-existent-repositories'
},
'nopath' => { 'path' => nil }
)
end
def value_from_redis(name)
Gitlab::Git::Storage.redis.with do |redis|
redis.hmget(cache_key, name)
end.first
end
def set_in_redis(name, value)
Gitlab::Git::Storage.redis.with do |redis|
redis.hmset(cache_key, name, value)
end.first
end
describe '.reset_all!' do
it 'clears all entries form redis' do
set_in_redis(:failure_count, 10)
described_class.reset_all!
key_exists = Gitlab::Git::Storage.redis.with { |redis| redis.exists(cache_key) }
expect(key_exists).to be_falsey
end
it 'does not break when there are no keys in redis' do
expect { described_class.reset_all! }.not_to raise_error
end
end
describe '.for_storage' do
it 'only builds a single circuitbreaker per storage' do
expect(described_class).to receive(:new).once.and_call_original
breaker = described_class.for_storage('default')
expect(breaker).to be_a(described_class)
expect(described_class.for_storage('default')).to eq(breaker)
end
it 'returns a broken circuit breaker for an unknown storage' do
expect(described_class.for_storage('unknown').circuit_broken?).to be_truthy
end
it 'returns a broken circuit breaker when the path is not set' do
expect(described_class.for_storage('nopath').circuit_broken?).to be_truthy
end
end
describe '#initialize' do
it 'assigns the settings' do
expect(circuit_breaker.hostname).to eq(hostname)
expect(circuit_breaker.storage).to eq('default')
expect(circuit_breaker.storage_path).to eq(TestEnv.repos_path)
end
end
context 'circuitbreaker settings' do
before do
stub_application_setting(circuitbreaker_failure_count_threshold: 0,
circuitbreaker_failure_wait_time: 1,
circuitbreaker_failure_reset_time: 2,
circuitbreaker_storage_timeout: 3)
end
describe '#failure_count_threshold' do
it 'reads the value from settings' do
expect(circuit_breaker.failure_count_threshold).to eq(0)
end
end
describe '#failure_wait_time' do
it 'reads the value from settings' do
expect(circuit_breaker.failure_wait_time).to eq(1)
end
end
describe '#failure_reset_time' do
it 'reads the value from settings' do
expect(circuit_breaker.failure_reset_time).to eq(2)
end
end
describe '#storage_timeout' do
it 'reads the value from settings' do
expect(circuit_breaker.storage_timeout).to eq(3)
end
end
end
describe '#perform' do
it 'raises an exception with retry time when the circuit is open' do
allow(circuit_breaker).to receive(:circuit_broken?).and_return(true)
expect { |b| circuit_breaker.perform(&b) }
.to raise_error(Gitlab::Git::Storage::CircuitOpen)
end
it 'yields the block' do
expect { |b| circuit_breaker.perform(&b) }
.to yield_control
end
it 'checks if the storage is available' do
expect(circuit_breaker).to receive(:check_storage_accessible!)
circuit_breaker.perform { 'hello world' }
end
it 'returns the value of the block' do
result = circuit_breaker.perform { 'return value' }
expect(result).to eq('return value')
end
it 'raises possible errors' do
expect { circuit_breaker.perform { raise Rugged::OSError.new('Broken') } }
.to raise_error(Rugged::OSError)
end
context 'with the feature disabled' do
it 'returns the block without checking accessibility' do
stub_feature_flags(git_storage_circuit_breaker: false)
expect(circuit_breaker).not_to receive(:circuit_broken?)
result = circuit_breaker.perform { 'hello' }
expect(result).to eq('hello')
end
end
end
describe '#circuit_broken?' do
it 'is working when there is no last failure' do
set_in_redis(:last_failure, nil)
set_in_redis(:failure_count, 0)
expect(circuit_breaker.circuit_broken?).to be_falsey
end
it 'is broken when there was a recent failure' do
Timecop.freeze do
set_in_redis(:last_failure, 1.second.ago.to_f)
set_in_redis(:failure_count, 1)
expect(circuit_breaker.circuit_broken?).to be_truthy
end
end
it 'is broken when there are too many failures' do
set_in_redis(:last_failure, 1.day.ago.to_f)
set_in_redis(:failure_count, 200)
expect(circuit_breaker.circuit_broken?).to be_truthy
end
context 'the `failure_wait_time` is set to 0' do
before do
stub_application_setting(circuitbreaker_failure_wait_time: 0)
end
it 'is working even when there is a recent failure' do
Timecop.freeze do
set_in_redis(:last_failure, 0.seconds.ago.to_f)
set_in_redis(:failure_count, 1)
expect(circuit_breaker.circuit_broken?).to be_falsey
end
end
end
end
describe "storage_available?" do
context 'the storage is available' do
it 'tracks that the storage was accessible an raises the error' do
expect(circuit_breaker).to receive(:track_storage_accessible)
circuit_breaker.storage_available?
end
it 'only performs the check once' do
expect(Gitlab::Git::Storage::ForkedStorageCheck)
.to receive(:storage_available?).once.and_call_original
2.times { circuit_breaker.storage_available? }
end
end
context 'storage is not available' do
let(:storage_name) { 'broken' }
it 'tracks that the storage was inaccessible' do
expect(circuit_breaker).to receive(:track_storage_inaccessible)
circuit_breaker.storage_available?
end
end
end
describe '#check_storage_accessible!' do
it 'raises an exception with retry time when the circuit is open' do
allow(circuit_breaker).to receive(:circuit_broken?).and_return(true)
expect { circuit_breaker.check_storage_accessible! }
.to raise_error do |exception|
expect(exception).to be_kind_of(Gitlab::Git::Storage::CircuitOpen)
expect(exception.retry_after).to eq(30)
end
end
context 'the storage is not available' do
let(:storage_name) { 'broken' }
it 'raises an error' do
expect(circuit_breaker).to receive(:track_storage_inaccessible)
expect { circuit_breaker.check_storage_accessible! }
.to raise_error do |exception|
expect(exception).to be_kind_of(Gitlab::Git::Storage::Inaccessible)
expect(exception.retry_after).to eq(30)
end
end
end
end
describe '#track_storage_inaccessible' do
around do |example|
Timecop.freeze { example.run }
end
it 'records the failure time in redis' do
circuit_breaker.track_storage_inaccessible
failure_time = value_from_redis(:last_failure)
expect(Time.at(failure_time.to_i)).to be_within(1.second).of(Time.now)
end
it 'sets the failure time on the breaker without reloading' do
circuit_breaker.track_storage_inaccessible
expect(circuit_breaker).not_to receive(:get_failure_info)
expect(circuit_breaker.last_failure).to eq(Time.now)
end
it 'increments the failure count in redis' do
set_in_redis(:failure_count, 10)
circuit_breaker.track_storage_inaccessible
expect(value_from_redis(:failure_count).to_i).to be(11)
end
it 'increments the failure count on the breaker without reloading' do
set_in_redis(:failure_count, 10)
circuit_breaker.track_storage_inaccessible
expect(circuit_breaker).not_to receive(:get_failure_info)
expect(circuit_breaker.failure_count).to eq(11)
end
end
describe '#track_storage_accessible' do
it 'sets the failure count to zero in redis' do
set_in_redis(:failure_count, 10)
circuit_breaker.track_storage_accessible
expect(value_from_redis(:failure_count).to_i).to be(0)
end
it 'sets the failure count to zero on the breaker without reloading' do
set_in_redis(:failure_count, 10)
circuit_breaker.track_storage_accessible
expect(circuit_breaker).not_to receive(:get_failure_info)
expect(circuit_breaker.failure_count).to eq(0)
end
it 'removes the last failure time from redis' do
set_in_redis(:last_failure, Time.now.to_i)
circuit_breaker.track_storage_accessible
expect(circuit_breaker).not_to receive(:get_failure_info)
expect(circuit_breaker.last_failure).to be_nil
end
it 'removes the last failure time from the breaker without reloading' do
set_in_redis(:last_failure, Time.now.to_i)
circuit_breaker.track_storage_accessible
expect(value_from_redis(:last_failure)).to be_empty
end
it 'wont connect to redis when there are no failures' do
expect(Gitlab::Git::Storage.redis).to receive(:with).once
.and_call_original
expect(circuit_breaker).to receive(:track_storage_accessible)
.and_call_original
circuit_breaker.track_storage_accessible
end
end
describe '#no_failures?' do
it 'is false when a failure was tracked' do
set_in_redis(:last_failure, Time.now.to_i)
set_in_redis(:failure_count, 1)
expect(circuit_breaker.no_failures?).to be_falsey
end
end
describe '#last_failure' do
it 'returns the last failure time' do
time = Time.parse("2017-05-26 17:52:30")
set_in_redis(:last_failure, time.to_i)
expect(circuit_breaker.last_failure).to eq(time)
end
end
describe '#failure_count' do
it 'returns the failure count' do
set_in_redis(:failure_count, 7)
expect(circuit_breaker.failure_count).to eq(7)
end
end
describe '#cache_key' do
it 'includes storage and host' do
expect(circuit_breaker.cache_key).to eq(cache_key)
end
end
end
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