// When there are more consumers in a group then partitions in a topic then
// some consumers get assigned no partitions and their consume requests timeout.
func (s *SmartConsumerSuite) TestTooFewPartitions(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.1")
produced := s.kh.PutMessages("few", "test.1", map[string]int{"": 3})
sc1, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
log.Infof("*** GIVEN 1")
// Consume first message to make `consumer-1` subscribe for `test.1`
consumed := s.consume(c, sc1, "group-1", "test.1", 2)
assertMsg(c, consumed[""][0], produced[""][0])
// When:
log.Infof("*** WHEN")
sc2, err := Spawn(testhelpers.NewTestConfig("consumer-2"))
c.Assert(err, IsNil)
_, err = sc2.Consume("group-1", "test.1")
// Then: `consumer-2` request times out, when `consumer-1` requests keep
// return messages.
log.Infof("*** THEN")
if _, ok := err.(ErrRequestTimeout); !ok {
c.Errorf("Expected ErrConsumerRequestTimeout, got %s", err)
}
s.consume(c, sc1, "group-1", "test.1", 1, consumed)
assertMsg(c, consumed[""][1], produced[""][1])
sc1.Stop()
sc2.Stop()
}
// When a consumer registration times out the partitions that used to be
// assigned to it are redistributed among active consumers.
func (s *SmartConsumerSuite) TestRebalanceOnTimeout(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.4")
s.kh.PutMessages("join", "test.4", map[string]int{"A": 10, "B": 10})
sc1, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
cfg2 := testhelpers.NewTestConfig("consumer-2")
cfg2.Consumer.RegistrationTimeout = 300 * time.Millisecond
sc2, err := Spawn(cfg2)
c.Assert(err, IsNil)
// Consume the first message to make the consumers join the group and
// subscribe to the topic.
log.Infof("*** GIVEN 1")
consumed1 := s.consume(c, sc1, "group-1", "test.4", 1)
consumed2 := s.consume(c, sc2, "group-1", "test.4", 1)
if len(consumed1["B"]) == 0 {
c.Assert(len(consumed1["A"]), Equals, 1)
} else {
c.Assert(len(consumed1["A"]), Equals, 0)
}
c.Assert(len(consumed2["A"]), Equals, 0)
c.Assert(len(consumed2["B"]), Equals, 1)
// Consume 4 more messages to make sure that each consumer pulls from a
// particular assigned to it.
log.Infof("*** GIVEN 2")
consumed1 = s.consume(c, sc1, "group-1", "test.4", 4, consumed1)
consumed2 = s.consume(c, sc2, "group-1", "test.4", 4, consumed2)
if len(consumed1["B"]) == 1 {
c.Assert(len(consumed1["A"]), Equals, 4)
} else {
c.Assert(len(consumed1["A"]), Equals, 5)
}
c.Assert(len(consumed2["A"]), Equals, 0)
c.Assert(len(consumed2["B"]), Equals, 5)
drainFirstFetched(sc1)
// When: `consumer-2` registration timeout elapses, the partitions get
// rebalanced so that `consumer-1` becomes assigned to all of them...
log.Infof("*** WHEN")
// Wait for partition `B` reassigned back to sc1.
waitFirstFetched(sc1, 1)
// ...and consumes the remaining messages from all partitions.
log.Infof("*** THEN")
consumed1 = s.consume(c, sc1, "group-1", "test.4", 10, consumed1)
c.Assert(len(consumed1["A"]), Equals, 10)
c.Assert(len(consumed1["B"]), Equals, 5)
c.Assert(len(consumed2["A"]), Equals, 0)
c.Assert(len(consumed2["B"]), Equals, 5)
sc2.Stop()
sc1.Stop()
}
// Different topics can be consumed at the same time.
func (s *SmartConsumerSuite) TestMultipleTopics(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.1")
s.kh.ResetOffsets("group-1", "test.4")
produced1 := s.kh.PutMessages("multiple.topics", "test.1", map[string]int{"A": 1})
produced4 := s.kh.PutMessages("multiple.topics", "test.4", map[string]int{"B": 1, "C": 1})
log.Infof("*** GIVEN 1")
sc, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
// When
log.Infof("*** WHEN")
consumed := s.consume(c, sc, "group-1", "test.4", 1)
consumed = s.consume(c, sc, "group-1", "test.1", 1, consumed)
consumed = s.consume(c, sc, "group-1", "test.4", 1, consumed)
// Then
log.Infof("*** THEN")
assertMsg(c, consumed["A"][0], produced1["A"][0])
assertMsg(c, consumed["B"][0], produced4["B"][0])
assertMsg(c, consumed["C"][0], produced4["C"][0])
sc.Stop()
}
// If we consume from a topic that has several partitions then partitions are
// selected for consumption in random order.
func (s *SmartConsumerSuite) TestMultiplePartitions(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.4")
s.kh.PutMessages("multiple.partitions", "test.4", map[string]int{"A": 100, "B": 100})
log.Infof("*** GIVEN 1")
sc, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
// When: exactly one half of all produced events is consumed.
log.Infof("*** WHEN")
consumed := s.consume(c, sc, "group-1", "test.4", 1)
// Wait until first messages from partitions `A` and `B` are fetched.
waitFirstFetched(sc, 2)
// Consume 100 messages total
consumed = s.consume(c, sc, "group-1", "test.4", 99, consumed)
// Then: we have events consumed from both partitions more or less evenly.
log.Infof("*** THEN")
if len(consumed["A"]) < 25 || len(consumed["A"]) > 75 {
c.Errorf("Consumption disbalance: consumed[A]=%d, consumed[B]=%d", len(consumed["A"]), len(consumed["B"]))
}
sc.Stop()
}
// If we stop one consumer and start another, the new one picks up where the
// previous one left off.
func (s *SmartConsumerSuite) TestSequentialConsume(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.1")
produced := s.kh.PutMessages("sequencial", "test.1", map[string]int{"": 3})
cfg := testhelpers.NewTestConfig("consumer-1")
sc1, err := Spawn(cfg)
c.Assert(err, IsNil)
log.Infof("*** GIVEN 1")
consumed := s.consume(c, sc1, "group-1", "test.1", 2)
assertMsg(c, consumed[""][0], produced[""][0])
assertMsg(c, consumed[""][1], produced[""][1])
// When: one consumer stopped and another one takes its place.
log.Infof("*** WHEN")
sc1.Stop()
sc2, err := Spawn(cfg)
c.Assert(err, IsNil)
// Then: the second message is consumed.
log.Infof("*** THEN")
consumed = s.consume(c, sc2, "group-1", "test.1", 1, consumed)
assertMsg(c, consumed[""][2], produced[""][2])
sc2.Stop()
}
// A topic that has a lot of partitions can be consumed.
func (s *SmartConsumerSuite) TestLotsOfPartitions(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.64")
cfg := testhelpers.NewTestConfig("consumer-1")
sc, err := Spawn(cfg)
c.Assert(err, IsNil)
// Consume should stop by timeout and nothing should be consumed.
msg, err := sc.Consume("group-1", "test.64")
if _, ok := err.(ErrRequestTimeout); !ok {
c.Fatalf("Unexpected message consumed: %v", msg)
}
s.kh.PutMessages("lots", "test.64", map[string]int{"A": 7, "B": 13, "C": 169})
// When
log.Infof("*** WHEN")
consumed := s.consume(c, sc, "group-1", "test.64", consumeAll)
// Then
log.Infof("*** THEN")
c.Assert(7, Equals, len(consumed["A"]))
c.Assert(13, Equals, len(consumed["B"]))
c.Assert(169, Equals, len(consumed["C"]))
sc.Stop()
}
// When a topic is consumed by a consumer group for the first time, its head
// offset is committed, to make sure that subsequently submitted messages are
// consumed.
func (s *SmartConsumerSuite) TestNewGroup(c *C) {
// Given
group := fmt.Sprintf("group-%d", time.Now().Unix())
cfg := testhelpers.NewTestConfig(group)
cfg.Consumer.LongPollingTimeout = 500 * time.Millisecond
sc, err := Spawn(cfg)
c.Assert(err, IsNil)
s.kh.PutMessages("rand", "test.1", map[string]int{"A1": 1})
// The very first consumption of a group is terminated by timeout because
// the default offset is the topic head.
msg, err := sc.Consume(group, "test.1")
if _, ok := err.(ErrRequestTimeout); !ok {
c.Fatalf("Unexpected message consumed: %v", msg)
}
// When: consumer is stopped, the concrete head offset is committed.
sc.Stop()
// Then: message produced after that will be consumed by the new consumer
// instance from the same group.
produced := s.kh.PutMessages("rand", "test.1", map[string]int{"A2": 1})
sc, err = Spawn(cfg)
c.Assert(err, IsNil)
msg, err = sc.Consume(group, "test.1")
c.Assert(err, IsNil)
assertMsg(c, msg, produced["A2"][0])
sc.Stop()
}
// This test makes an attempt to exercise the code path where a message is
// received when a down stream dispatch tier is being stopped due to
// registration timeout, in that case a successor tier is created that will be
// started as soon as the original one is completely shutdown.
//
// It is impossible to see from the service behavior if the expected code path
// has been exercised by the test. The only way to check that is through the
// code coverage reports.
func (s *SmartConsumerSuite) TestRequestDuringTimeout(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.4")
s.kh.PutMessages("join", "test.4", map[string]int{"A": 30})
cfg := testhelpers.NewTestConfig("consumer-1")
cfg.Consumer.RegistrationTimeout = 200 * time.Millisecond
cfg.Consumer.ChannelBufferSize = 1
sc, err := Spawn(cfg)
c.Assert(err, IsNil)
// When/Then
for i := 0; i < 10; i++ {
for j := 0; j < 3; j++ {
begin := time.Now()
log.Infof("*** consuming...")
consMsg, err := sc.Consume("group-1", "test.4")
c.Assert(err, IsNil)
log.Infof("*** consumed: in=%s, by=%s, topic=%s, partition=%d, offset=%d, message=%s",
time.Now().Sub(begin), sc.baseCID.String(), consMsg.Topic, consMsg.Partition, consMsg.Offset, consMsg.Value)
}
time.Sleep(200 * time.Millisecond)
}
sc.Stop()
}
// A `ErrConsumerBufferOverflow` error can be returned if internal buffers are
// filled with in-flight consume requests.
func (s *SmartConsumerSuite) TestBufferOverflowError(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.1")
s.kh.PutMessages("join", "test.1", map[string]int{"A": 30})
cfg := testhelpers.NewTestConfig("consumer-1")
cfg.Consumer.ChannelBufferSize = 1
sc, err := Spawn(cfg)
c.Assert(err, IsNil)
// When
var overflowErrorCount int32
var wg sync.WaitGroup
for i := 0; i < 3; i++ {
spawn(&wg, func() {
for i := 0; i < 10; i++ {
_, err := sc.Consume("group-1", "test.1")
if _, ok := err.(ErrBufferOverflow); ok {
atomic.AddInt32(&overflowErrorCount, 1)
}
}
})
}
wg.Wait()
// Then
c.Assert(overflowErrorCount, Not(Equals), 0)
log.Infof("*** overflow was hit %d times", overflowErrorCount)
sc.Stop()
}
// When a new consumer joins a group the partitions get evenly redistributed
// among all consumers.
func (s *SmartConsumerSuite) TestRebalanceOnJoin(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.4")
s.kh.PutMessages("join", "test.4", map[string]int{"A": 10, "B": 10})
sc1, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
// Consume the first message to make the consumer join the group and
// subscribe to the topic.
log.Infof("*** GIVEN 1")
consumed1 := s.consume(c, sc1, "group-1", "test.4", 1)
// Wait until first messages from partitions `A` and `B` are fetched.
waitFirstFetched(sc1, 2)
// Consume 4 messages and make sure that there are messages from both
// partitions among them.
log.Infof("*** GIVEN 2")
consumed1 = s.consume(c, sc1, "group-1", "test.4", 4, consumed1)
c.Assert(len(consumed1["A"]), Not(Equals), 0)
c.Assert(len(consumed1["B"]), Not(Equals), 0)
consumedBeforeJoin := len(consumed1["B"])
// When: another consumer joins the group rebalancing occurs.
log.Infof("*** WHEN")
sc2, err := Spawn(testhelpers.NewTestConfig("consumer-2"))
c.Assert(err, IsNil)
// Then:
log.Infof("*** THEN")
consumed2 := s.consume(c, sc2, "group-1", "test.4", consumeAll)
consumed1 = s.consume(c, sc1, "group-1", "test.4", consumeAll, consumed1)
// Partition "A" has been consumed by `consumer-1` only
c.Assert(len(consumed1["A"]), Equals, 10)
c.Assert(len(consumed2["A"]), Equals, 0)
// Partition "B" has been consumed by both consumers, but ever since
// `consumer-2` joined the group the first one have not got any new messages.
c.Assert(len(consumed1["B"]), Equals, consumedBeforeJoin)
c.Assert(len(consumed2["B"]), Not(Equals), 0)
c.Assert(len(consumed1["B"])+len(consumed2["B"]), Equals, 10)
// `consumer-2` started consumer from where `consumer-1` left off.
c.Assert(consumed2["B"][0].Offset, Equals, consumed1["B"][len(consumed1["B"])-1].Offset+1)
sc2.Stop()
sc1.Stop()
}
func spawnTestService(c *C, port int) *T {
config := testhelpers.NewTestConfig(fmt.Sprintf("C%d", port))
config.UnixAddr = fmt.Sprintf("%s.%d", config.UnixAddr, port)
os.Remove(config.UnixAddr)
config.TCPAddr = fmt.Sprintf("127.0.0.1:%d", port)
svc, err := Spawn(config)
c.Assert(err, IsNil)
return svc
}
func (s *ServiceSuite) SetUpTest(c *C) {
s.cfg = testhelpers.NewTestConfig("service-default")
os.Remove(s.cfg.UnixAddr)
s.kh = testhelpers.NewKafkaHelper(c)
s.unixClient = testhelpers.NewUDSHTTPClient(s.cfg.UnixAddr)
// The default HTTP client cannot be used, because it caches connections,
// but each test must have a brand new connection.
s.tcpClient = &http.Client{Transport: &http.Transport{
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
}}
}
// If a topic has only one partition then the consumer will retrieve messages
// in the order they were produced.
func (s *SmartConsumerSuite) TestSinglePartitionTopic(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.1")
produced := s.kh.PutMessages("single", "test.1", map[string]int{"": 3})
sc, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
// When/Then
consumed := s.consume(c, sc, "group-1", "test.1", 1)
assertMsg(c, consumed[""][0], produced[""][0])
sc.Stop()
}
// If an attempt is made to consume from a topic that does not exist then the
// request times out after `Config.Consumer.LongPollingTimeout`.
func (s *SmartConsumerSuite) TestInvalidTopic(c *C) {
// Given
cfg := testhelpers.NewTestConfig("consumer-1")
cfg.Consumer.LongPollingTimeout = 1 * time.Second
sc, err := Spawn(cfg)
c.Assert(err, IsNil)
// When
consMsg, err := sc.Consume("group-1", "no-such-topic")
// Then
if _, ok := err.(ErrRequestTimeout); !ok {
c.Errorf("ErrConsumerRequestTimeout is expected")
}
c.Assert(consMsg, IsNil)
sc.Stop()
}
func (s *ServiceSuite) TestGetTopicConsumersOne(c *C) {
// Given
s.kh.ResetOffsets("foo", "test.4")
s.kh.PutMessages("get.consumers", "test.4", map[string]int{"A": 1, "B": 1, "C": 1, "D": 1})
svc, _ := Spawn(testhelpers.NewTestConfig("C1"))
defer svc.Stop()
for i := 0; i < 4; i++ {
s.unixClient.Get("http://_/topics/test.4/messages?group=foo")
}
// When
r, err := s.unixClient.Get("http://_/topics/test.4/consumers?group=foo")
// Then
c.Assert(err, IsNil)
c.Assert(r.StatusCode, Equals, http.StatusOK)
consumers := ParseJSONBody(c, r).(map[string]interface{})
assertConsumedPartitions(c, consumers, map[string]map[string][]int32{
"foo": {
"C1": {0, 1, 2, 3}},
})
}
// If the same topic is consumed by different consumer groups, then consumption
// by one group does not affect the consumption by another.
func (s *SmartConsumerSuite) TestMultipleGroups(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.4")
s.kh.ResetOffsets("group-2", "test.4")
s.kh.PutMessages("multi", "test.4", map[string]int{"A": 10, "B": 10, "C": 10})
log.Infof("*** GIVEN 1")
sc, err := Spawn(testhelpers.NewTestConfig("consumer-1"))
c.Assert(err, IsNil)
// When
log.Infof("*** WHEN")
consumed1 := s.consume(c, sc, "group-1", "test.4", 10)
consumed2 := s.consume(c, sc, "group-2", "test.4", 20)
consumed1 = s.consume(c, sc, "group-1", "test.4", 20, consumed1)
consumed2 = s.consume(c, sc, "group-2", "test.4", 10, consumed2)
// Then: both groups consumed the same events
log.Infof("*** THEN")
c.Assert(consumed1, DeepEquals, consumed2)
sc.Stop()
}
// When a consumer leaves a group the partitions get evenly redistributed
// among the remaining consumers.
func (s *SmartConsumerSuite) TestRebalanceOnLeave(c *C) {
// Given
s.kh.ResetOffsets("group-1", "test.4")
produced := s.kh.PutMessages("leave", "test.4", map[string]int{"A": 10, "B": 10, "C": 10})
var err error
consumers := make([]*T, 3)
for i := 0; i < 3; i++ {
consumers[i], err = Spawn(testhelpers.NewTestConfig(fmt.Sprintf("consumer-%d", i)))
c.Assert(err, IsNil)
}
log.Infof("*** GIVEN 1")
// Consume the first message to make the consumer join the group and
// subscribe to the topic.
consumed := make([]map[string][]*sarama.ConsumerMessage, 3)
for i := 0; i < 3; i++ {
consumed[i] = s.consume(c, consumers[i], "group-1", "test.4", 1)
}
// consumer[0] can consume the first message from all partitions and
// consumer[1] can consume the first message from either `B` or `C`.
log.Infof("*** GIVEN 2")
if len(consumed[0]["A"]) == 1 {
if len(consumed[1]["B"]) == 1 {
assertMsg(c, consumed[2]["B"][0], produced["B"][1])
} else { // if len(consumed[1]["C"]) == 1 {
assertMsg(c, consumed[2]["B"][0], produced["B"][0])
}
} else if len(consumed[0]["B"]) == 1 {
if len(consumed[1]["B"]) == 1 {
assertMsg(c, consumed[2]["B"][0], produced["B"][2])
} else { // if len(consumed[1]["C"]) == 1 {
assertMsg(c, consumed[2]["B"][0], produced["B"][1])
}
} else { // if len(consumed[0]["C"]) == 1 {
if len(consumed[1]["B"]) == 1 {
assertMsg(c, consumed[2]["B"][0], produced["B"][1])
} else { // if len(consumed[1]["C"]) == 1 {
assertMsg(c, consumed[2]["B"][0], produced["B"][0])
}
}
s.consume(c, consumers[2], "group-1", "test.4", 4, consumed[2])
c.Assert(len(consumed[2]["B"]), Equals, 5)
lastConsumedFromBby2 := consumed[2]["B"][4]
for _, consumer := range consumers {
drainFirstFetched(consumer)
}
// When
log.Infof("*** WHEN")
consumers[2].Stop()
// Wait for partition `C` reassign back to consumer[1]
waitFirstFetched(consumers[1], 1)
// Then: partition `B` is reassigned to `consumer[1]` and it picks up where
// `consumer[2]` left off.
log.Infof("*** THEN")
consumedSoFar := make(map[string]int)
for _, consumedByOne := range consumed {
for key, consumedWithKey := range consumedByOne {
consumedSoFar[key] = consumedSoFar[key] + len(consumedWithKey)
}
}
leftToBeConsumedBy1 := 20 - (consumedSoFar["B"] + consumedSoFar["C"])
consumedBy1 := s.consume(c, consumers[1], "group-1", "test.4", leftToBeConsumedBy1)
c.Assert(len(consumedBy1["B"]), Equals, 10-consumedSoFar["B"])
c.Assert(consumedBy1["B"][0].Offset, Equals, lastConsumedFromBby2.Offset+1)
consumers[0].Stop()
consumers[1].Stop()
}