/
nsq_consumer.go
197 lines (166 loc) · 4.06 KB
/
nsq_consumer.go
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//go:generate ../../../tools/readme_config_includer/generator
package nsq_consumer
import (
"context"
_ "embed"
"errors"
"fmt"
"sync"
"github.com/nsqio/go-nsq"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
//go:embed sample.conf
var sampleConfig string
const (
defaultMaxUndeliveredMessages = 1000
)
type empty struct{}
type semaphore chan empty
type logger struct {
log telegraf.Logger
}
func (l *logger) Output(_ int, s string) error {
l.log.Debug(s)
return nil
}
// NSQConsumer represents the configuration of the plugin
type NSQConsumer struct {
Server string `toml:"server" deprecated:"1.5.0;use 'nsqd' instead"`
Nsqd []string `toml:"nsqd"`
Nsqlookupd []string `toml:"nsqlookupd"`
Topic string `toml:"topic"`
Channel string `toml:"channel"`
MaxInFlight int `toml:"max_in_flight"`
MaxUndeliveredMessages int `toml:"max_undelivered_messages"`
parser telegraf.Parser
consumer *nsq.Consumer
Log telegraf.Logger
mu sync.Mutex
messages map[telegraf.TrackingID]*nsq.Message
wg sync.WaitGroup
cancel context.CancelFunc
}
func (*NSQConsumer) SampleConfig() string {
return sampleConfig
}
// SetParser takes the data_format from the config and finds the right parser for that format
func (n *NSQConsumer) SetParser(parser telegraf.Parser) {
n.parser = parser
}
// Start pulls data from nsq
func (n *NSQConsumer) Start(ac telegraf.Accumulator) error {
acc := ac.WithTracking(n.MaxUndeliveredMessages)
sem := make(semaphore, n.MaxUndeliveredMessages)
n.messages = make(map[telegraf.TrackingID]*nsq.Message, n.MaxUndeliveredMessages)
ctx, cancel := context.WithCancel(context.Background())
n.cancel = cancel
if err := n.connect(); err != nil {
return err
}
n.consumer.SetLogger(&logger{log: n.Log}, nsq.LogLevelInfo)
n.consumer.AddHandler(nsq.HandlerFunc(func(message *nsq.Message) error {
metrics, err := n.parser.Parse(message.Body)
if err != nil {
acc.AddError(err)
// Remove the message from the queue
message.Finish()
return nil
}
if len(metrics) == 0 {
message.Finish()
return nil
}
select {
case <-ctx.Done():
return ctx.Err()
case sem <- empty{}:
break
}
n.mu.Lock()
id := acc.AddTrackingMetricGroup(metrics)
n.messages[id] = message
n.mu.Unlock()
message.DisableAutoResponse()
return nil
}))
// For backward compatibility
if n.Server != "" {
n.Nsqd = append(n.Nsqd, n.Server)
}
// Check if we have anything to connect to
if len(n.Nsqlookupd) == 0 && len(n.Nsqd) == 0 {
return fmt.Errorf("either 'nsqd' or 'nsqlookupd' needs to be specified")
}
if len(n.Nsqlookupd) > 0 {
err := n.consumer.ConnectToNSQLookupds(n.Nsqlookupd)
if err != nil && !errors.Is(err, nsq.ErrAlreadyConnected) {
return err
}
}
if len(n.Nsqd) > 0 {
err := n.consumer.ConnectToNSQDs(n.Nsqd)
if err != nil && !errors.Is(err, nsq.ErrAlreadyConnected) {
return err
}
}
n.wg.Add(1)
go func() {
defer n.wg.Done()
n.onDelivery(ctx, acc, sem)
}()
return nil
}
func (n *NSQConsumer) onDelivery(ctx context.Context, acc telegraf.TrackingAccumulator, sem semaphore) {
for {
select {
case <-ctx.Done():
return
case info := <-acc.Delivered():
n.mu.Lock()
msg, ok := n.messages[info.ID()]
if !ok {
n.mu.Unlock()
continue
}
<-sem
delete(n.messages, info.ID())
n.mu.Unlock()
if info.Delivered() {
msg.Finish()
} else {
msg.Requeue(-1)
}
}
}
}
// Stop processing messages
func (n *NSQConsumer) Stop() {
n.cancel()
n.wg.Wait()
n.consumer.Stop()
<-n.consumer.StopChan
}
// Gather is a noop
func (n *NSQConsumer) Gather(_ telegraf.Accumulator) error {
return nil
}
func (n *NSQConsumer) connect() error {
if n.consumer == nil {
config := nsq.NewConfig()
config.MaxInFlight = n.MaxInFlight
consumer, err := nsq.NewConsumer(n.Topic, n.Channel, config)
if err != nil {
return err
}
n.consumer = consumer
}
return nil
}
func init() {
inputs.Add("nsq_consumer", func() telegraf.Input {
return &NSQConsumer{
MaxUndeliveredMessages: defaultMaxUndeliveredMessages,
}
})
}