// New creates a new CircuitBreaker middleware
func New(next http.Handler, expression string, options ...CircuitBreakerOption) (*CircuitBreaker, error) {
cb := &CircuitBreaker{
m: &sync.RWMutex{},
next: next,
// Default values. Might be overwritten by options below.
clock: &timetools.RealTime{},
checkPeriod: defaultCheckPeriod,
fallbackDuration: defaultFallbackDuration,
recoveryDuration: defaultRecoveryDuration,
fallback: defaultFallback,
log: utils.NullLogger,
}
for _, s := range options {
if err := s(cb); err != nil {
return nil, err
}
}
condition, err := parseExpression(expression)
if err != nil {
return nil, err
}
cb.condition = condition
mt, err := memmetrics.NewRTMetrics()
if err != nil {
return nil, err
}
cb.metrics = mt
return cb, nil
}
func statsOK() *memmetrics.RTMetrics {
m, err := memmetrics.NewRTMetrics()
if err != nil {
panic(err)
}
return m
}
func (m *mux) ServerStats(key engine.ServerKey) (*engine.RoundTripStats, error) {
log.Infof("%s ServerStats", m)
m.mtx.RLock()
defer m.mtx.RUnlock()
b, ok := m.backends[key.BackendKey]
if !ok {
return nil, fmt.Errorf("%v not found", key.BackendKey)
}
srv, ok := b.findServer(key)
if !ok {
return nil, fmt.Errorf("%v not found", key)
}
u, err := url.Parse(srv.URL)
if err != nil {
return nil, err
}
rtm, err := memmetrics.NewRTMetrics()
if err != nil {
return nil, err
}
for _, f := range m.frontends {
if f.backend.backend.Id != key.BackendKey.Id {
continue
}
if err := f.watcher.collectServerMetrics(rtm, u); err != nil {
return nil, err
}
}
return engine.NewRoundTripStats(rtm)
}
func (mx *mux) serverStats(key engine.ServerKey) (*engine.RoundTripStats, error) {
b, ok := mx.backends[key.BackendKey]
if !ok {
return nil, fmt.Errorf("%v not found", key.BackendKey)
}
srv, ok := b.findServer(key)
if !ok {
return nil, fmt.Errorf("%v not found", key)
}
u, err := url.Parse(srv.URL)
if err != nil {
return nil, err
}
m, err := memmetrics.NewRTMetrics()
if err != nil {
return nil, err
}
for _, f := range mx.frontends {
if f.backend.backend.Id != key.BackendKey.Id {
continue
}
if err := f.watcher.collectServerMetrics(m, u); err != nil {
return nil, err
}
}
return engine.NewRoundTripStats(m)
}
func statsLatencyAtQuantile(quantile float64, value time.Duration) *memmetrics.RTMetrics {
m, err := memmetrics.NewRTMetrics()
if err != nil {
panic(err)
}
m.Record(http.StatusOK, value)
return m
}
func newSval(s engine.Server) (*sval, error) {
rtm, err := memmetrics.NewRTMetrics()
if err != nil {
return nil, err
}
u, err := url.Parse(s.URL)
if err != nil {
return nil, err
}
return &sval{srv: &s, rtm: rtm, url: u}, nil
}
func statsResponseCodes(codes ...statusCode) *memmetrics.RTMetrics {
m, err := memmetrics.NewRTMetrics()
if err != nil {
panic(err)
}
for _, c := range codes {
for i := int64(0); i < c.Count; i++ {
m.Record(c.Code, 0)
}
}
return m
}
func statsNetErrors(threshold float64) *memmetrics.RTMetrics {
m, err := memmetrics.NewRTMetrics()
if err != nil {
panic(err)
}
for i := 0; i < 100; i++ {
if i < int(threshold*100) {
m.Record(http.StatusGatewayTimeout, 0)
} else {
m.Record(http.StatusOK, 0)
}
}
return m
}
func (mx *mux) backendStats(key engine.BackendKey) (*engine.RoundTripStats, error) {
m, err := memmetrics.NewRTMetrics()
if err != nil {
return nil, err
}
for _, f := range mx.frontends {
if f.backend.backend.Id != key.Id {
continue
}
if err := f.watcher.collectMetrics(m); err != nil {
return nil, err
}
}
return engine.NewRoundTripStats(m)
}
func (m *mux) BackendStats(key engine.BackendKey) (*engine.RoundTripStats, error) {
log.Infof("%s BackendStats", m)
m.mtx.RLock()
defer m.mtx.RUnlock()
rtm, err := memmetrics.NewRTMetrics()
if err != nil {
return nil, err
}
for _, f := range m.frontends {
if f.backend.backend.Id != key.Id {
continue
}
if err := f.watcher.collectMetrics(rtm); err != nil {
return nil, err
}
}
return engine.NewRoundTripStats(rtm)
}