/
presence_test.go
554 lines (462 loc) · 13 KB
/
presence_test.go
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// Copyright 2012, 2013 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package presence_test
import (
"strconv"
stdtesting "testing"
"time"
"github.com/juju/errors"
"github.com/juju/names"
gitjujutesting "github.com/juju/testing"
jc "github.com/juju/testing/checkers"
"github.com/juju/utils"
gc "gopkg.in/check.v1"
"gopkg.in/mgo.v2"
"launchpad.net/tomb"
"github.com/juju/juju/state/presence"
"github.com/juju/juju/testing"
)
func TestPackage(t *stdtesting.T) {
testing.MgoTestPackage(t)
}
type PresenceSuite struct {
gitjujutesting.MgoSuite
testing.BaseSuite
presence *mgo.Collection
pings *mgo.Collection
modelTag names.ModelTag
}
var _ = gc.Suite(&PresenceSuite{})
func (s *PresenceSuite) SetUpSuite(c *gc.C) {
s.BaseSuite.SetUpSuite(c)
s.MgoSuite.SetUpSuite(c)
uuid, err := utils.NewUUID()
c.Assert(err, jc.ErrorIsNil)
s.modelTag = names.NewModelTag(uuid.String())
}
func (s *PresenceSuite) TearDownSuite(c *gc.C) {
s.MgoSuite.TearDownSuite(c)
s.BaseSuite.TearDownSuite(c)
}
func (s *PresenceSuite) SetUpTest(c *gc.C) {
s.BaseSuite.SetUpTest(c)
s.MgoSuite.SetUpTest(c)
db := s.MgoSuite.Session.DB("presence")
s.presence = db.C("presence")
s.pings = db.C("presence.pings")
presence.FakeTimeSlot(0)
}
func (s *PresenceSuite) TearDownTest(c *gc.C) {
s.MgoSuite.TearDownTest(c)
s.BaseSuite.TearDownTest(c)
presence.RealTimeSlot()
presence.RealPeriod()
}
func assertChange(c *gc.C, watch <-chan presence.Change, want presence.Change) {
select {
case got := <-watch:
if got != want {
c.Fatalf("watch reported %v, want %v", got, want)
}
case <-time.After(testing.LongWait):
c.Fatalf("watch reported nothing, want %v", want)
}
}
func assertNoChange(c *gc.C, watch <-chan presence.Change) {
select {
case got := <-watch:
c.Fatalf("watch reported %v, want nothing", got)
case <-time.After(testing.ShortWait):
}
}
func assertAlive(c *gc.C, w *presence.Watcher, key string, alive bool) {
alive, err := w.Alive("a")
c.Assert(err, jc.ErrorIsNil)
c.Assert(alive, gc.Equals, alive)
}
func (s *PresenceSuite) TestErrAndDead(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
defer w.Stop()
c.Assert(errors.Cause(w.Err()), gc.Equals, tomb.ErrStillAlive)
select {
case <-w.Dead():
c.Fatalf("Dead channel fired unexpectedly")
default:
}
c.Assert(w.Stop(), gc.IsNil)
c.Assert(w.Err(), gc.IsNil)
select {
case <-w.Dead():
default:
c.Fatalf("Dead channel should have fired")
}
}
// assertStopped stops a worker and waits until it reports stopped.
// Use this method in favor of defer w.Stop() because you _must_ ensure
// that the worker has stopped, and thus is no longer using its mgo
// session before TearDownTest shuts down the connection.
func assertStopped(c *gc.C, w worker.Worker) {
c.Assert(w.Stop(), gc.IsNil)
w.Wait()
}
func (s *PresenceSuite) TestAliveError(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
c.Assert(w.Stop(), gc.IsNil)
alive, err := w.Alive("a")
c.Assert(err, gc.ErrorMatches, ".*: watcher is dying")
c.Assert(alive, jc.IsFalse)
w.Wait()
}
func (s *PresenceSuite) TestWorkflow(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
pa := presence.NewPinger(s.presence, s.modelTag, "a")
pb := presence.NewPinger(s.presence, s.modelTag, "b")
defer assertStopped(c, w)
defer assertStopped(c, pa)
defer assertStopped(c, pb)
assertAlive(c, w, "a", false)
assertAlive(c, w, "b", false)
// Buffer one entry to avoid blocking the watcher here.
cha := make(chan presence.Change, 1)
chb := make(chan presence.Change, 1)
w.Watch("a", cha)
w.Watch("b", chb)
// Initial events with current status.
assertChange(c, cha, presence.Change{"a", false})
assertChange(c, chb, presence.Change{"b", false})
w.StartSync()
assertNoChange(c, cha)
assertNoChange(c, chb)
c.Assert(pa.Start(), gc.IsNil)
w.StartSync()
assertChange(c, cha, presence.Change{"a", true})
assertNoChange(c, cha)
assertNoChange(c, chb)
assertAlive(c, w, "a", true)
assertAlive(c, w, "b", false)
// Changes while the channel is out are not observed.
w.Unwatch("a", cha)
assertNoChange(c, cha)
pa.KillForTesting()
w.Sync()
pa = presence.NewPinger(s.presence, s.modelTag, "a")
pa.Start()
w.StartSync()
assertNoChange(c, cha)
// We can still query it manually, though.
assertAlive(c, w, "a", true)
assertAlive(c, w, "b", false)
// Initial positive event. No refresh needed.
w.Watch("a", cha)
assertChange(c, cha, presence.Change{"a", true})
c.Assert(pb.Start(), gc.IsNil)
w.StartSync()
assertChange(c, chb, presence.Change{"b", true})
assertNoChange(c, cha)
assertNoChange(c, chb)
c.Assert(pa.Stop(), gc.IsNil)
w.StartSync()
assertNoChange(c, cha)
assertNoChange(c, chb)
// pb is running, pa isn't.
c.Assert(pa.KillForTesting(), gc.IsNil)
c.Assert(pb.KillForTesting(), gc.IsNil)
w.StartSync()
assertChange(c, cha, presence.Change{"a", false})
assertChange(c, chb, presence.Change{"b", false})
assertStopped(c, w)
}
func (s *PresenceSuite) TestScale(c *gc.C) {
const N = 1000
var ps []*presence.Pinger
defer func() {
for _, p := range ps {
p.Stop()
}
}()
c.Logf("Starting %d pingers...", N)
for i := 0; i < N; i++ {
p := presence.NewPinger(s.presence, s.modelTag, strconv.Itoa(i))
c.Assert(p.Start(), gc.IsNil)
ps = append(ps, p)
}
c.Logf("Killing odd ones...")
for i := 1; i < N; i += 2 {
c.Assert(ps[i].KillForTesting(), gc.IsNil)
}
c.Logf("Checking who's still alive...")
w := presence.NewWatcher(s.presence, s.modelTag)
defer assertStopped(c, w)
w.Sync()
ch := make(chan presence.Change)
for i := 0; i < N; i++ {
k := strconv.Itoa(i)
w.Watch(k, ch)
if i%2 == 0 {
assertChange(c, ch, presence.Change{k, true})
} else {
assertChange(c, ch, presence.Change{k, false})
}
}
}
func (s *PresenceSuite) TestExpiry(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
p := presence.NewPinger(s.presence, s.modelTag, "a")
defer assertStopped(w, c)
defer assertStopped(w, p)
ch := make(chan presence.Change)
w.Watch("a", ch)
assertChange(c, ch, presence.Change{"a", false})
c.Assert(p.Start(), gc.IsNil)
w.StartSync()
assertChange(c, ch, presence.Change{"a", true})
// Still alive in previous slot.
presence.FakeTimeSlot(1)
w.StartSync()
assertNoChange(c, ch)
// Two last slots are empty.
presence.FakeTimeSlot(2)
w.StartSync()
assertChange(c, ch, presence.Change{"a", false})
// Already dead so killing isn't noticed.
p.KillForTesting()
w.StartSync()
assertNoChange(c, ch)
}
func (s *PresenceSuite) TestWatchPeriod(c *gc.C) {
presence.FakePeriod(1)
presence.RealTimeSlot()
w := presence.NewWatcher(s.presence, s.modelTag)
p := presence.NewPinger(s.presence, s.modelTag, "a")
defer assertStopped(c, w)
defer assertStopped(c, p)
ch := make(chan presence.Change)
w.Watch("a", ch)
assertChange(c, ch, presence.Change{"a", false})
// A single ping.
c.Assert(p.Start(), gc.IsNil)
c.Assert(p.Stop(), gc.IsNil)
// Wait for next periodic refresh.
time.Sleep(1 * time.Second)
assertChange(c, ch, presence.Change{"a", true})
}
func (s *PresenceSuite) TestWatchUnwatchOnQueue(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
ch := make(chan presence.Change)
for i := 0; i < 100; i++ {
key := strconv.Itoa(i)
c.Logf("Adding %q", key)
w.Watch(key, ch)
}
for i := 1; i < 100; i += 2 {
key := strconv.Itoa(i)
c.Logf("Removing %q", key)
w.Unwatch(key, ch)
}
alive := make(map[string]bool)
for i := 0; i < 50; i++ {
change := <-ch
c.Logf("Got change for %q: %v", change.Key, change.Alive)
alive[change.Key] = change.Alive
}
for i := 0; i < 100; i += 2 {
key := strconv.Itoa(i)
c.Logf("Checking %q...", key)
c.Assert(alive[key], jc.IsFalse)
}
}
func (s *PresenceSuite) TestRestartWithoutGaps(c *gc.C) {
p := presence.NewPinger(s.presence, s.modelTag, "a")
c.Assert(p.Start(), gc.IsNil)
defer assertStopped(c, p)
done := make(chan bool)
go func() {
stop := false
for !stop {
if !c.Check(p.Stop(), gc.IsNil) {
break
}
if !c.Check(p.Start(), gc.IsNil) {
break
}
select {
case stop = <-done:
default:
}
}
}()
go func() {
stop := false
for !stop {
w := presence.NewWatcher(s.presence, s.modelTag)
w.Sync()
alive, err := w.Alive("a")
assertStopped(c, w)
if !c.Check(err, jc.ErrorIsNil) || !c.Check(alive, jc.IsTrue) {
break
}
select {
case stop = <-done:
default:
}
}
}()
// TODO(jam): This forceful delay of 500ms sounds like a bad test,
// since we always sleep for the full timeout
time.Sleep(500 * time.Millisecond)
done <- true
done <- true
}
func (s *PresenceSuite) TestPingerPeriodAndResilience(c *gc.C) {
// This test verifies both the periodic pinging,
// and also a great property of the design: deaths
// also expire, which means erroneous scenarios are
// automatically recovered from.
const period = 1
presence.FakePeriod(period)
presence.RealTimeSlot()
w := presence.NewWatcher(s.presence, s.modelTag)
p1 := presence.NewPinger(s.presence, s.modelTag, "a")
p2 := presence.NewPinger(s.presence, s.modelTag, "a")
defer assertStopped(c, w)
defer assertStopped(c, p1)
defer assertStopped(c, p2)
// Start p1 and let it go on.
c.Assert(p1.Start(), gc.IsNil)
w.Sync()
assertAlive(c, w, "a", true)
// Start and kill p2, which will temporarily
// invalidate p1 and set the key as dead.
c.Assert(p2.Start(), gc.IsNil)
c.Assert(p2.KillForTesting(), gc.IsNil)
w.Sync()
assertAlive(c, w, "a", false)
// Wait for two periods, and check again. Since
// p1 is still alive, p2's death will expire and
// the key will come back.
time.Sleep(period * 2 * time.Second)
w.Sync()
assertAlive(c, w, "a", true)
}
func (s *PresenceSuite) TestStartSync(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
p := presence.NewPinger(s.presence, s.modelTag, "a")
defer assertStopped(c, w)
defer assertStopped(c, p)
ch := make(chan presence.Change)
w.Watch("a", ch)
assertChange(c, ch, presence.Change{"a", false})
c.Assert(p.Start(), gc.IsNil)
done := make(chan bool)
go func() {
w.StartSync()
w.StartSync()
w.StartSync()
done <- true
}()
select {
case <-done:
case <-time.After(testing.LongWait):
c.Fatalf("StartSync failed to return")
}
assertChange(c, ch, presence.Change{"a", true})
}
func (s *PresenceSuite) TestSync(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
p := presence.NewPinger(s.presence, s.modelTag, "a")
defer assertStopped(c, w)
defer assertStopped(c, p)
ch := make(chan presence.Change)
w.Watch("a", ch)
assertChange(c, ch, presence.Change{"a", false})
// Nothing to do here.
w.Sync()
c.Assert(p.Start(), gc.IsNil)
done := make(chan bool)
go func() {
w.Sync()
done <- true
}()
select {
case <-done:
c.Fatalf("Sync returned too early")
// Note(jam): This used to wait 200ms to ensure that
// Sync was actually blocked waiting for a presence
// change. Is ShortWait long enough for this assurance?
case <-time.After(testing.ShortWait):
}
assertChange(c, ch, presence.Change{"a", true})
select {
case <-done:
case <-time.After(testing.LongWait):
c.Fatalf("Sync failed to returned")
}
}
func (s *PresenceSuite) TestFindAllBeings(c *gc.C) {
w := presence.NewWatcher(s.presence, s.modelTag)
p := presence.NewPinger(s.presence, s.modelTag, "a")
defer assertStopped(c, w)
defer assertStopped(c, p)
ch := make(chan presence.Change)
w.Watch("a", ch)
assertChange(c, ch, presence.Change{"a", false})
c.Assert(p.Start(), gc.IsNil)
done := make(chan bool)
go func() {
w.Sync()
done <- true
}()
assertChange(c, ch, presence.Change{"a", true})
results, err := presence.FindAllBeings(w)
c.Assert(err, jc.ErrorIsNil)
c.Assert(results, gc.HasLen, 1)
select {
case <-done:
case <-time.After(testing.LongWait):
c.Fatalf("Sync failed to returned")
}
}
func (s *PresenceSuite) TestTwoEnvironments(c *gc.C) {
key := "a"
w1, p1, ch1 := s.setup(c, key)
defer assertStopped(c, w1)
defer assertStopped(c, p1)
w2, p2, ch2 := s.setup(c, key)
defer assertStopped(c, w2)
defer assertStopped(c, p2)
c.Assert(p1.Start(), gc.IsNil)
w1.StartSync()
w2.StartSync()
assertNoChange(c, ch2)
assertChange(c, ch1, presence.Change{"a", true})
c.Assert(p2.Start(), gc.IsNil)
w1.StartSync()
w2.StartSync()
assertNoChange(c, ch1)
assertChange(c, ch2, presence.Change{"a", true})
err := p1.KillForTesting()
c.Assert(err, jc.ErrorIsNil)
presence.FakeTimeSlot(1)
w1.StartSync()
w2.StartSync()
assertChange(c, ch1, presence.Change{"a", false})
assertNoChange(c, ch2)
err = p2.KillForTesting()
c.Assert(err, jc.ErrorIsNil)
presence.FakeTimeSlot(2)
w1.StartSync()
w2.StartSync()
assertChange(c, ch2, presence.Change{"a", false})
assertNoChange(c, ch1)
}
func (s *PresenceSuite) setup(c *gc.C, key string) (*presence.Watcher, *presence.Pinger, <-chan presence.Change) {
uuid, err := utils.NewUUID()
c.Assert(err, jc.ErrorIsNil)
modelUUID := uuid.String()
w := presence.NewWatcher(s.presence, names.NewModelTag(modelUUID))
p := presence.NewPinger(s.presence, names.NewModelTag(modelUUID), key)
ch := make(chan presence.Change)
w.Watch(key, ch)
assertChange(c, ch, presence.Change{key, false})
return w, p, ch
}