GODT-1348: max 100 conn per host

pkg/pmapi/dialer_basic.go

@@ -33,9 +33,11 @@ func CreateTransportWithDialer(dialer TLSDialer) *http.Transport {
 	return &http.Transport{
 		DialTLS: dialer.DialTLS,
 
-		Proxy:                 http.ProxyFromEnvironment,
-		MaxIdleConns:          100,
-		IdleConnTimeout:       5 * time.Minute,
+		Proxy:               http.ProxyFromEnvironment,
+		MaxIdleConns:        100,
+		MaxIdleConnsPerHost: 100,
+		IdleConnTimeout:     5 * time.Minute,
+
 		ExpectContinueTimeout: 500 * time.Millisecond,
 
 		// GODT-126: this was initially 10s but logs from users showed a significant number

pkg/pmapi/manager.go

@@ -43,7 +43,7 @@ func New(cfg Config) Manager {
 func newManager(cfg Config) *manager {
 	m := &manager{
 		cfg:    cfg,
-		rc:     resty.New(),
+		rc:     resty.New().EnableTrace(),
 		locker: &sync.Mutex{},
 	}
 
@@ -59,6 +59,7 @@ func newManager(cfg Config) *manager {
 	// wrapped in JSON. If error is returned, `handleRequestFailure` is called,
 	// otherwise `handleRequestSuccess` is called.
 	m.rc.SetError(&Error{})
+	m.rc.OnAfterResponse(logConnReuse)
 	m.rc.OnAfterResponse(updateTime)
 	m.rc.OnAfterResponse(m.catchAPIError)
 	m.rc.OnAfterResponse(m.handleRequestSuccess)

pkg/pmapi/response.go

@@ -82,6 +82,14 @@ func updateTime(_ *resty.Client, res *resty.Response) error {
 	return nil
 }
 
+func logConnReuse(_ *resty.Client, res *resty.Response) error {
+	if !res.Request.TraceInfo().IsConnReused {
+		logrus.WithField("host", res.Request.URL).Trace("Connection was NOT reused")
+	}
+
+	return nil
+}
+
 func catchRetryAfter(_ *resty.Client, res *resty.Response) (time.Duration, error) {
 	if res.StatusCode() == http.StatusTooManyRequests {
 		if after := res.Header().Get("Retry-After"); after != "" {