Esempio n. 1
0
func (s *RBSuite) TestRebalancerLive(c *C) {
	a, b := testutils.NewResponder("a"), testutils.NewResponder("b")
	defer a.Close()
	defer b.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	rb, err := NewRebalancer(lb, RebalancerBackoff(time.Millisecond), RebalancerClock(s.clock))
	c.Assert(err, IsNil)

	rb.UpsertServer(testutils.ParseURI(a.URL))
	rb.UpsertServer(testutils.ParseURI(b.URL))
	rb.UpsertServer(testutils.ParseURI("http://localhost:62345"))

	proxy := httptest.NewServer(rb)
	defer proxy.Close()

	for i := 0; i < 1000; i += 1 {
		testutils.Get(proxy.URL)
		if i%10 == 0 {
			s.clock.CurrentTime = s.clock.CurrentTime.Add(rb.backoffDuration + time.Second)
		}
	}

	// load balancer changed weights
	c.Assert(rb.servers[0].curWeight, Equals, FSMMaxWeight)
	c.Assert(rb.servers[1].curWeight, Equals, FSMMaxWeight)
	c.Assert(rb.servers[2].curWeight, Equals, 1)
}
Esempio n. 2
0
func (s *RBSuite) TestRebalancerRemoveServer(c *C) {
	a, b := testutils.NewResponder("a"), testutils.NewResponder("b")
	defer a.Close()
	defer b.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	rb, err := NewRebalancer(lb)
	c.Assert(err, IsNil)

	rb.UpsertServer(testutils.ParseURI(a.URL))
	rb.UpsertServer(testutils.ParseURI(b.URL))

	proxy := httptest.NewServer(rb)
	defer proxy.Close()

	c.Assert(seq(c, proxy.URL, 3), DeepEquals, []string{"a", "b", "a"})

	c.Assert(rb.RemoveServer(testutils.ParseURI(a.URL)), IsNil)
	c.Assert(seq(c, proxy.URL, 3), DeepEquals, []string{"b", "b", "b"})
}
Esempio n. 3
0
func (s *RRSuite) TestWeighted(c *C) {
	a := testutils.NewResponder("a")
	defer a.Close()

	b := testutils.NewResponder("b")
	defer b.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	lb.UpsertServer(testutils.ParseURI(a.URL), Weight(3))
	lb.UpsertServer(testutils.ParseURI(b.URL), Weight(2))

	proxy := httptest.NewServer(lb)
	defer proxy.Close()

	c.Assert(seq(c, proxy.URL, 6), DeepEquals, []string{"a", "a", "b", "a", "b", "a"})

	w, ok := lb.ServerWeight(testutils.ParseURI(a.URL))
	c.Assert(w, Equals, 3)
	c.Assert(ok, Equals, true)

	w, ok = lb.ServerWeight(testutils.ParseURI(b.URL))
	c.Assert(w, Equals, 2)
	c.Assert(ok, Equals, true)

	w, ok = lb.ServerWeight(testutils.ParseURI("http://caramba:4000"))
	c.Assert(w, Equals, -1)
	c.Assert(ok, Equals, false)
}
Esempio n. 4
0
func (s *RRSuite) TestUpsertWeight(c *C) {
	a := testutils.NewResponder("a")
	defer a.Close()

	b := testutils.NewResponder("b")
	defer b.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	c.Assert(lb.UpsertServer(testutils.ParseURI(a.URL)), IsNil)
	c.Assert(lb.UpsertServer(testutils.ParseURI(b.URL)), IsNil)

	proxy := httptest.NewServer(lb)
	defer proxy.Close()

	c.Assert(seq(c, proxy.URL, 3), DeepEquals, []string{"a", "b", "a"})

	c.Assert(lb.UpsertServer(testutils.ParseURI(b.URL), Weight(3)), IsNil)

	c.Assert(seq(c, proxy.URL, 4), DeepEquals, []string{"b", "b", "a", "b"})
}
Esempio n. 5
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// Test scenario when increaing the weight on good endpoints made it worse
func (s *RBSuite) TestRebalancerCascading(c *C) {
	a, b, d := testutils.NewResponder("a"), testutils.NewResponder("b"), testutils.NewResponder("d")
	defer a.Close()
	defer b.Close()
	defer d.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	newMeter := func() (Meter, error) {
		return &testMeter{}, nil
	}
	rb, err := NewRebalancer(lb, RebalancerMeter(newMeter), RebalancerClock(s.clock), RebalancerLogger(s.log))
	c.Assert(err, IsNil)

	rb.UpsertServer(testutils.ParseURI(a.URL))
	rb.UpsertServer(testutils.ParseURI(b.URL))
	rb.UpsertServer(testutils.ParseURI(d.URL))
	rb.servers[0].meter.(*testMeter).rating = 0.3

	proxy := httptest.NewServer(rb)
	defer proxy.Close()

	for i := 0; i < 6; i += 1 {
		testutils.Get(proxy.URL)
		testutils.Get(proxy.URL)
		s.clock.CurrentTime = s.clock.CurrentTime.Add(rb.backoffDuration + time.Second)
	}

	// We have increased the load, and the situation became worse as the other servers started failing
	c.Assert(rb.servers[0].curWeight, Equals, 1)
	c.Assert(rb.servers[1].curWeight, Equals, FSMMaxWeight)
	c.Assert(rb.servers[2].curWeight, Equals, FSMMaxWeight)

	// server a is now recovering, the weights should go back to the original state
	rb.servers[0].meter.(*testMeter).rating = 0.3
	rb.servers[1].meter.(*testMeter).rating = 0.2
	rb.servers[2].meter.(*testMeter).rating = 0.2

	for i := 0; i < 6; i += 1 {
		testutils.Get(proxy.URL)
		testutils.Get(proxy.URL)
		s.clock.CurrentTime = s.clock.CurrentTime.Add(rb.backoffDuration + time.Second)
	}

	// the algo reverted it back
	c.Assert(rb.servers[0].curWeight, Equals, 1)
	c.Assert(rb.servers[1].curWeight, Equals, 1)
	c.Assert(rb.servers[2].curWeight, Equals, 1)
}
Esempio n. 6
0
// Test scenario when one server goes down after what it recovers
func (s *RBSuite) TestRebalancerRecovery(c *C) {
	a, b := testutils.NewResponder("a"), testutils.NewResponder("b")
	defer a.Close()
	defer b.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	newMeter := func() (Meter, error) {
		return &testMeter{}, nil
	}
	rb, err := NewRebalancer(lb, RebalancerMeter(newMeter), RebalancerClock(s.clock), RebalancerLogger(s.log))
	c.Assert(err, IsNil)

	rb.UpsertServer(testutils.ParseURI(a.URL))
	rb.UpsertServer(testutils.ParseURI(b.URL))
	rb.servers[0].meter.(*testMeter).rating = 0.3

	proxy := httptest.NewServer(rb)
	defer proxy.Close()

	for i := 0; i < 6; i += 1 {
		testutils.Get(proxy.URL)
		testutils.Get(proxy.URL)
		s.clock.CurrentTime = s.clock.CurrentTime.Add(rb.backoffDuration + time.Second)
	}

	c.Assert(rb.servers[0].curWeight, Equals, 1)
	c.Assert(rb.servers[1].curWeight, Equals, FSMMaxWeight)

	c.Assert(lb.servers[0].weight, Equals, 1)
	c.Assert(lb.servers[1].weight, Equals, FSMMaxWeight)

	// server a is now recovering, the weights should go back to the original state
	rb.servers[0].meter.(*testMeter).rating = 0

	for i := 0; i < 6; i += 1 {
		testutils.Get(proxy.URL)
		testutils.Get(proxy.URL)
		s.clock.CurrentTime = s.clock.CurrentTime.Add(rb.backoffDuration + time.Second)
	}

	c.Assert(rb.servers[0].curWeight, Equals, 1)
	c.Assert(rb.servers[1].curWeight, Equals, 1)

	// Make sure we have applied the weights to the inner load balancer
	c.Assert(lb.servers[0].weight, Equals, 1)
	c.Assert(lb.servers[1].weight, Equals, 1)
}
Esempio n. 7
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// Removing the server resets the state
func (s *RBSuite) TestRebalancerReset(c *C) {
	a, b, d := testutils.NewResponder("a"), testutils.NewResponder("b"), testutils.NewResponder("d")
	defer a.Close()
	defer b.Close()
	defer d.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	newMeter := func() (Meter, error) {
		return &testMeter{}, nil
	}
	rb, err := NewRebalancer(lb, RebalancerMeter(newMeter), RebalancerClock(s.clock), RebalancerLogger(s.log))
	c.Assert(err, IsNil)

	rb.UpsertServer(testutils.ParseURI(a.URL))
	rb.UpsertServer(testutils.ParseURI(b.URL))
	rb.UpsertServer(testutils.ParseURI(d.URL))
	rb.servers[0].meter.(*testMeter).rating = 0.3
	rb.servers[1].meter.(*testMeter).rating = 0
	rb.servers[2].meter.(*testMeter).rating = 0

	proxy := httptest.NewServer(rb)
	defer proxy.Close()

	for i := 0; i < 6; i += 1 {
		testutils.Get(proxy.URL)
		testutils.Get(proxy.URL)
		s.clock.CurrentTime = s.clock.CurrentTime.Add(rb.backoffDuration + time.Second)
	}

	// load balancer changed weights
	c.Assert(rb.servers[0].curWeight, Equals, 1)
	c.Assert(rb.servers[1].curWeight, Equals, FSMMaxWeight)
	c.Assert(rb.servers[2].curWeight, Equals, FSMMaxWeight)

	// Removing servers has reset the state
	rb.RemoveServer(testutils.ParseURI(d.URL))

	c.Assert(rb.servers[0].curWeight, Equals, 1)
	c.Assert(rb.servers[1].curWeight, Equals, 1)
}
Esempio n. 8
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func (s *RBSuite) TestRebalancerNormalOperation(c *C) {
	a, b := testutils.NewResponder("a"), testutils.NewResponder("b")
	defer a.Close()
	defer b.Close()

	fwd, err := forward.New()
	c.Assert(err, IsNil)

	lb, err := New(fwd)
	c.Assert(err, IsNil)

	rb, err := NewRebalancer(lb)
	c.Assert(err, IsNil)

	rb.UpsertServer(testutils.ParseURI(a.URL))
	c.Assert(rb.Servers()[0].String(), Equals, a.URL)

	proxy := httptest.NewServer(rb)
	defer proxy.Close()

	c.Assert(seq(c, proxy.URL, 3), DeepEquals, []string{"a", "a", "a"})
}