21023: Use known-good exponential backoff with jitter strategy.

[arvados.git] / sdk / go / keepclient / keepclient_test.go

diff --git a/sdk/go/keepclient/keepclient_test.go b/sdk/go/keepclient/keepclient_test.go
index 19a6d4e03b7103feeb48f33efb9a990457dc3c14..4cfe1a08961166592b12805d03e4ee3207ab7236 100644 (file)
--- a/sdk/go/keepclient/keepclient_test.go
+++ b/sdk/go/keepclient/keepclient_test.go
@@ -798,8 +798,12 @@ func (s *StandaloneSuite) TestGetFail(c *C) {
 }
 
 func (s *StandaloneSuite) TestGetFailRetry(c *C) {
-       defer func(orig time.Duration) { DefaultRetryDelay = orig }(DefaultRetryDelay)
+       defer func(origDefault, origMinimum time.Duration) {
+               DefaultRetryDelay = origDefault
+               MinimumRetryDelay = origMinimum
+       }(DefaultRetryDelay, MinimumRetryDelay)
        DefaultRetryDelay = time.Second / 8
+       MinimumRetryDelay = time.Millisecond
 
        hash := fmt.Sprintf("%x+3", md5.Sum([]byte("foo")))
 
@@ -839,7 +843,7 @@ func (s *StandaloneSuite) TestGetFailRetry(c *C) {
                if expect == 0 {
                        expect = DefaultRetryDelay
                }
-               min := expect + expect*7/4 + expect*7/4*7/4
+               min := MinimumRetryDelay * 3
                max := expect + expect*2 + expect*2*2 + nonsleeptime
                c.Check(elapsed >= min, Equals, true, Commentf("elapsed %v / expect min %v", elapsed, min))
                c.Check(elapsed <= max, Equals, true, Commentf("elapsed %v / expect max %v", elapsed, max))
@@ -1502,8 +1506,12 @@ func (s *StandaloneSuite) TestGetIndexWithNoSuchPrefix(c *C) {
 }
 
 func (s *StandaloneSuite) TestPutBRetry(c *C) {
-       defer func(orig time.Duration) { DefaultRetryDelay = orig }(DefaultRetryDelay)
+       defer func(origDefault, origMinimum time.Duration) {
+               DefaultRetryDelay = origDefault
+               MinimumRetryDelay = origMinimum
+       }(DefaultRetryDelay, MinimumRetryDelay)
        DefaultRetryDelay = time.Second / 8
+       MinimumRetryDelay = time.Millisecond
 
        for _, delay := range []time.Duration{0, time.Nanosecond, time.Second / 8, time.Second / 16} {
                c.Logf("=== initial delay %v", delay)
@@ -1556,8 +1564,9 @@ func (s *StandaloneSuite) TestPutBRetry(c *C) {
                if expect == 0 {
                        expect = DefaultRetryDelay
                }
-               min := expect + expect*7/4 + expect*7/4*7/4
-               max := expect + expect*2 + expect*2*2 + nonsleeptime
+               min := MinimumRetryDelay * 3
+               max := expect + expect*2 + expect*2*2
+               max += nonsleeptime
                c.Check(elapsed >= min, Equals, true, Commentf("elapsed %v / expect min %v", elapsed, min))
                c.Check(elapsed <= max, Equals, true, Commentf("elapsed %v / expect max %v", elapsed, max))
        }
@@ -1608,3 +1617,51 @@ func (s *ServerRequiredSuite) TestMakeKeepClientWithNonDiskTypeService(c *C) {
        c.Assert(kc.foundNonDiskSvc, Equals, true)
        c.Assert(kc.httpClient().(*http.Client).Timeout, Equals, 300*time.Second)
 }
+
+func (s *StandaloneSuite) TestDelayCalculator(c *C) {
+       defer func(origDefault, origMinimum time.Duration) {
+               DefaultRetryDelay = origDefault
+               MinimumRetryDelay = origMinimum
+       }(DefaultRetryDelay, MinimumRetryDelay)
+
+       checkInterval := func(d, min, max time.Duration) {
+               c.Check(d >= min, Equals, true)
+               c.Check(d <= max, Equals, true)
+       }
+
+       MinimumRetryDelay = time.Second / 2
+       DefaultRetryDelay = time.Second
+       dc := delayCalculator{InitialMaxDelay: 0}
+       checkInterval(dc.Next(), time.Second/2, time.Second)
+       checkInterval(dc.Next(), time.Second/2, time.Second*2)
+       checkInterval(dc.Next(), time.Second/2, time.Second*4)
+       checkInterval(dc.Next(), time.Second/2, time.Second*8)
+       checkInterval(dc.Next(), time.Second/2, time.Second*10)
+       checkInterval(dc.Next(), time.Second/2, time.Second*10)
+
+       // Enforce non-zero InitialMaxDelay
+       dc = delayCalculator{InitialMaxDelay: time.Second}
+       checkInterval(dc.Next(), time.Second/2, time.Second*2)
+       checkInterval(dc.Next(), time.Second/2, time.Second*4)
+       checkInterval(dc.Next(), time.Second/2, time.Second*8)
+       checkInterval(dc.Next(), time.Second/2, time.Second*16)
+       checkInterval(dc.Next(), time.Second/2, time.Second*20)
+       checkInterval(dc.Next(), time.Second/2, time.Second*20)
+
+       // Enforce MinimumRetryDelay
+       dc = delayCalculator{InitialMaxDelay: time.Millisecond}
+       checkInterval(dc.Next(), time.Second/2, time.Second/2)
+       checkInterval(dc.Next(), time.Second/2, time.Second)
+       checkInterval(dc.Next(), time.Second/2, time.Second*2)
+       checkInterval(dc.Next(), time.Second/2, time.Second*4)
+       checkInterval(dc.Next(), time.Second/2, time.Second*8)
+       checkInterval(dc.Next(), time.Second/2, time.Second*10)
+       checkInterval(dc.Next(), time.Second/2, time.Second*10)
+
+       // If InitialMaxDelay is less than MinimumRetryDelay/10, then
+       // delay is always MinimumRetryDelay.
+       dc = delayCalculator{InitialMaxDelay: time.Millisecond}
+       for i := 0; i < 20; i++ {
+               c.Check(dc.Next(), Equals, time.Second/2)
+       }
+}