dom/telegraf
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Use sarama built in support for consumer groups (#6172)

Browse Source
This commit is contained in:
Daniel Nelson
2019-07-29 20:41:12 -07:00
committed by GitHub
parent 4d73290e13
commit aea09b3a20
8 changed files with 691 additions and 481 deletions
Download Patch File Download Diff File Expand all files Collapse all files

427
plugins/inputs/kafka_consumer/kafka_consumer.go
View File

@@ -8,61 +8,20 @@ import (
"sync"
"github.com/Shopify/sarama"
cluster "github.com/bsm/sarama-cluster"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal/tls"
"github.com/influxdata/telegraf/plugins/inputs"
"github.com/influxdata/telegraf/plugins/parsers"
)
const (
defaultMaxUndeliveredMessages = 1000
)
type empty struct{}
type semaphore chan empty
type Consumer interface {
Errors() <-chan error
Messages() <-chan *sarama.ConsumerMessage
MarkOffset(msg *sarama.ConsumerMessage, metadata string)
Close() error
}
type Kafka struct {
ConsumerGroup string `toml:"consumer_group"`
ClientID string `toml:"client_id"`
Topics []string `toml:"topics"`
Brokers []string `toml:"brokers"`
MaxMessageLen int `toml:"max_message_len"`
Version string `toml:"version"`
MaxUndeliveredMessages int `toml:"max_undelivered_messages"`
Offset string `toml:"offset"`
SASLUsername string `toml:"sasl_username"`
SASLPassword string `toml:"sasl_password"`
TopicTag string `toml:"topic_tag"`
tls.ClientConfig
cluster Consumer
parser parsers.Parser
wg *sync.WaitGroup
cancel context.CancelFunc
// Unconfirmed messages
messages map[telegraf.TrackingID]*sarama.ConsumerMessage
// doNotCommitMsgs tells the parser not to call CommitUpTo on the consumer
// this is mostly for test purposes, but there may be a use-case for it later.
doNotCommitMsgs bool
}
var sampleConfig = `
## kafka servers
const sampleConfig = `
## Kafka brokers.
brokers = ["localhost:9092"]
## topic(s) to consume
## Topics to consume.
topics = ["telegraf"]
## Add topic as tag if topic_tag is not empty
## When set this tag will be added to all metrics with the topic as the value.
# topic_tag = ""
## Optional Client id
@@ -85,10 +44,12 @@ var sampleConfig = `
# sasl_username = "kafka"
# sasl_password = "secret"
## the name of the consumer group
consumer_group = "telegraf_metrics_consumers"
## Offset (must be either "oldest" or "newest")
offset = "oldest"
## Name of the consumer group.
# consumer_group = "telegraf_metrics_consumers"
## Initial offset position; one of "oldest" or "newest".
# offset = "oldest"
## Maximum length of a message to consume, in bytes (default 0/unlimited);
## larger messages are dropped
max_message_len = 1000000
@@ -110,22 +71,77 @@ var sampleConfig = `
data_format = "influx"
`
func (k *Kafka) SampleConfig() string {
const (
defaultMaxUndeliveredMessages = 1000
defaultMaxMessageLen = 1000000
defaultConsumerGroup = "telegraf_metrics_consumers"
)
type empty struct{}
type semaphore chan empty
type KafkaConsumer struct {
Brokers []string `toml:"brokers"`
ClientID string `toml:"client_id"`
ConsumerGroup string `toml:"consumer_group"`
MaxMessageLen int `toml:"max_message_len"`
MaxUndeliveredMessages int `toml:"max_undelivered_messages"`
Offset string `toml:"offset"`
Topics []string `toml:"topics"`
TopicTag string `toml:"topic_tag"`
Version string `toml:"version"`
SASLPassword string `toml:"sasl_password"`
SASLUsername string `toml:"sasl_username"`
tls.ClientConfig
ConsumerCreator ConsumerGroupCreator `toml:"-"`
consumer ConsumerGroup
config *sarama.Config
parser parsers.Parser
wg sync.WaitGroup
cancel context.CancelFunc
}
type ConsumerGroup interface {
Consume(ctx context.Context, topics []string, handler sarama.ConsumerGroupHandler) error
Errors() <-chan error
Close() error
}
type ConsumerGroupCreator interface {
Create(brokers []string, group string, config *sarama.Config) (ConsumerGroup, error)
}
type SaramaCreator struct{}
func (*SaramaCreator) Create(brokers []string, group string, config *sarama.Config) (ConsumerGroup, error) {
return sarama.NewConsumerGroup(brokers, group, config)
}
func (k *KafkaConsumer) SampleConfig() string {
return sampleConfig
}
func (k *Kafka) Description() string {
return "Read metrics from Kafka topic(s)"
func (k *KafkaConsumer) Description() string {
return "Read metrics from Kafka topics"
}
func (k *Kafka) SetParser(parser parsers.Parser) {
func (k *KafkaConsumer) SetParser(parser parsers.Parser) {
k.parser = parser
}
func (k *Kafka) Start(acc telegraf.Accumulator) error {
var clusterErr error
func (k *KafkaConsumer) Init() error {
if k.MaxUndeliveredMessages == 0 {
k.MaxUndeliveredMessages = defaultMaxUndeliveredMessages
}
if k.ConsumerGroup == "" {
k.ConsumerGroup = defaultConsumerGroup
}
config := cluster.NewConfig()
config := sarama.NewConfig()
config.Consumer.Return.Errors = true
if k.Version != "" {
version, err := sarama.ParseKafkaVersion(k.Version)
@@ -135,172 +151,255 @@ func (k *Kafka) Start(acc telegraf.Accumulator) error {
config.Version = version
}
config.Consumer.Return.Errors = true
tlsConfig, err := k.ClientConfig.TLSConfig()
if err != nil {
return err
}
if tlsConfig != nil {
config.Net.TLS.Config = tlsConfig
config.Net.TLS.Enable = true
}
if k.SASLUsername != "" && k.SASLPassword != "" {
config.Net.SASL.User = k.SASLUsername
config.Net.SASL.Password = k.SASLPassword
config.Net.SASL.Enable = true
}
if k.ClientID != "" {
config.ClientID = k.ClientID
} else {
config.ClientID = "Telegraf"
}
if tlsConfig != nil {
log.Printf("D! TLS Enabled")
config.Net.TLS.Config = tlsConfig
config.Net.TLS.Enable = true
}
if k.SASLUsername != "" && k.SASLPassword != "" {
log.Printf("D! Using SASL auth with username '%s',",
k.SASLUsername)
config.Net.SASL.User = k.SASLUsername
config.Net.SASL.Password = k.SASLPassword
config.Net.SASL.Enable = true
}
switch strings.ToLower(k.Offset) {
case "oldest", "":
config.Consumer.Offsets.Initial = sarama.OffsetOldest
case "newest":
config.Consumer.Offsets.Initial = sarama.OffsetNewest
default:
log.Printf("I! WARNING: Kafka consumer invalid offset '%s', using 'oldest'",
k.Offset)
config.Consumer.Offsets.Initial = sarama.OffsetOldest
return fmt.Errorf("invalid offset %q", k.Offset)
}
if k.cluster == nil {
k.cluster, clusterErr = cluster.NewConsumer(
k.Brokers,
k.ConsumerGroup,
k.Topics,
config,
)
if k.ConsumerCreator == nil {
k.ConsumerCreator = &SaramaCreator{}
}
if clusterErr != nil {
log.Printf("E! Error when creating Kafka Consumer, brokers: %v, topics: %v",
k.Brokers, k.Topics)
return clusterErr
}
k.config = config
return nil
}
func (k *KafkaConsumer) Start(acc telegraf.Accumulator) error {
var err error
k.consumer, err = k.ConsumerCreator.Create(
k.Brokers,
k.ConsumerGroup,
k.config,
)
if err != nil {
return err
}
ctx, cancel := context.WithCancel(context.Background())
k.cancel = cancel
// Start consumer goroutine
k.wg = &sync.WaitGroup{}
k.wg.Add(1)
go func() {
defer k.wg.Done()
k.receiver(ctx, acc)
for ctx.Err() == nil {
handler := NewConsumerGroupHandler(acc, k.MaxUndeliveredMessages, k.parser)
handler.MaxMessageLen = k.MaxMessageLen
handler.TopicTag = k.TopicTag
err := k.consumer.Consume(ctx, k.Topics, handler)
if err != nil {
acc.AddError(err)
}
}
err = k.consumer.Close()
if err != nil {
acc.AddError(err)
}
}()
k.wg.Add(1)
go func() {
defer k.wg.Done()
for err := range k.consumer.Errors() {
acc.AddError(err)
}
}()
log.Printf("I! Started the kafka consumer service, brokers: %v, topics: %v",
k.Brokers, k.Topics)
return nil
}
// receiver() reads all incoming messages from the consumer, and parses them into
// influxdb metric points.
func (k *Kafka) receiver(ctx context.Context, ac telegraf.Accumulator) {
k.messages = make(map[telegraf.TrackingID]*sarama.ConsumerMessage)
func (k *KafkaConsumer) Gather(acc telegraf.Accumulator) error {
return nil
}
acc := ac.WithTracking(k.MaxUndeliveredMessages)
sem := make(semaphore, k.MaxUndeliveredMessages)
func (k *KafkaConsumer) Stop() {
k.cancel()
k.wg.Wait()
}
// Message is an aggregate type binding the Kafka message and the session so
// that offsets can be updated.
type Message struct {
message *sarama.ConsumerMessage
session sarama.ConsumerGroupSession
}
func NewConsumerGroupHandler(acc telegraf.Accumulator, maxUndelivered int, parser parsers.Parser) *ConsumerGroupHandler {
handler := &ConsumerGroupHandler{
acc: acc.WithTracking(maxUndelivered),
sem: make(chan empty, maxUndelivered),
undelivered: make(map[telegraf.TrackingID]Message, maxUndelivered),
parser: parser,
}
return handler
}
// ConsumerGroupHandler is a sarama.ConsumerGroupHandler implementation.
type ConsumerGroupHandler struct {
MaxMessageLen int
TopicTag string
acc telegraf.TrackingAccumulator
sem semaphore
parser parsers.Parser
wg sync.WaitGroup
cancel context.CancelFunc
mu sync.Mutex
undelivered map[telegraf.TrackingID]Message
}
// Setup is called once when a new session is opened. It setups up the handler
// and begins processing delivered messages.
func (h *ConsumerGroupHandler) Setup(sarama.ConsumerGroupSession) error {
h.undelivered = make(map[telegraf.TrackingID]Message)
ctx, cancel := context.WithCancel(context.Background())
h.cancel = cancel
h.wg.Add(1)
go func() {
defer h.wg.Done()
h.run(ctx)
}()
return nil
}
// Run processes any delivered metrics during the lifetime of the session.
func (h *ConsumerGroupHandler) run(ctx context.Context) error {
for {
select {
case <-ctx.Done():
return
case track := <-acc.Delivered():
<-sem
k.onDelivery(track)
case err := <-k.cluster.Errors():
acc.AddError(err)
case sem <- empty{}:
select {
case <-ctx.Done():
return
case track := <-acc.Delivered():
// Once for the delivered message, once to leave the case
<-sem
<-sem
k.onDelivery(track)
case err := <-k.cluster.Errors():
<-sem
acc.AddError(err)
case msg := <-k.cluster.Messages():
err := k.onMessage(acc, msg)
if err != nil {
acc.AddError(err)
<-sem
}
}
return nil
case track := <-h.acc.Delivered():
h.onDelivery(track)
}
}
}
func (k *Kafka) markOffset(msg *sarama.ConsumerMessage) {
if !k.doNotCommitMsgs {
k.cluster.MarkOffset(msg, "")
}
}
func (h *ConsumerGroupHandler) onDelivery(track telegraf.DeliveryInfo) {
h.mu.Lock()
defer h.mu.Unlock()
func (k *Kafka) onMessage(acc telegraf.TrackingAccumulator, msg *sarama.ConsumerMessage) error {
if k.MaxMessageLen != 0 && len(msg.Value) > k.MaxMessageLen {
k.markOffset(msg)
return fmt.Errorf("Message longer than max_message_len (%d > %d)",
len(msg.Value), k.MaxMessageLen)
}
metrics, err := k.parser.Parse(msg.Value)
if err != nil {
return err
}
if len(k.TopicTag) > 0 {
for _, metric := range metrics {
metric.AddTag(k.TopicTag, msg.Topic)
}
}
id := acc.AddTrackingMetricGroup(metrics)
k.messages[id] = msg
return nil
}
func (k *Kafka) onDelivery(track telegraf.DeliveryInfo) {
msg, ok := k.messages[track.ID()]
msg, ok := h.undelivered[track.ID()]
if !ok {
log.Printf("E! [inputs.kafka_consumer] Could not mark message delivered: %d", track.ID())
return
}
if track.Delivered() {
k.markOffset(msg)
msg.session.MarkMessage(msg.message, "")
}
delete(k.messages, track.ID())
delete(h.undelivered, track.ID())
<-h.sem
}
func (k *Kafka) Stop() {
k.cancel()
k.wg.Wait()
if err := k.cluster.Close(); err != nil {
log.Printf("E! [inputs.kafka_consumer] Error closing consumer: %v", err)
// Reserve blocks until there is an available slot for a new message.
func (h *ConsumerGroupHandler) Reserve(ctx context.Context) error {
select {
case <-ctx.Done():
return ctx.Err()
case h.sem <- empty{}:
return nil
}
}
func (k *Kafka) Gather(acc telegraf.Accumulator) error {
func (h *ConsumerGroupHandler) release() {
<-h.sem
}
// Handle processes a message and if successful saves it to be acknowledged
// after delivery.
func (h *ConsumerGroupHandler) Handle(session sarama.ConsumerGroupSession, msg *sarama.ConsumerMessage) error {
if h.MaxMessageLen != 0 && len(msg.Value) > h.MaxMessageLen {
session.MarkMessage(msg, "")
h.release()
return fmt.Errorf("message exceeds max_message_len (actual %d, max %d)",
len(msg.Value), h.MaxMessageLen)
}
metrics, err := h.parser.Parse(msg.Value)
if err != nil {
h.release()
return err
}
if len(h.TopicTag) > 0 {
for _, metric := range metrics {
metric.AddTag(h.TopicTag, msg.Topic)
}
}
id := h.acc.AddTrackingMetricGroup(metrics)
h.mu.Lock()
h.undelivered[id] = Message{session: session, message: msg}
h.mu.Unlock()
return nil
}
// ConsumeClaim is called once each claim in a goroutine and must be
// thread-safe. Should run until the claim is closed.
func (h *ConsumerGroupHandler) ConsumeClaim(session sarama.ConsumerGroupSession, claim sarama.ConsumerGroupClaim) error {
ctx := session.Context()
for {
err := h.Reserve(ctx)
if err != nil {
return nil
}
select {
case <-ctx.Done():
return nil
case msg, ok := <-claim.Messages():
if !ok {
return nil
}
err := h.Handle(session, msg)
if err != nil {
h.acc.AddError(err)
}
}
}
}
// Cleanup stops the internal goroutine and is called after all ConsumeClaim
// functions have completed.
func (h *ConsumerGroupHandler) Cleanup(sarama.ConsumerGroupSession) error {
h.cancel()
h.wg.Wait()
return nil
}
func init() {
inputs.Add("kafka_consumer", func() telegraf.Input {
return &Kafka{
MaxUndeliveredMessages: defaultMaxUndeliveredMessages,
}
return &KafkaConsumer{}
})
}