Telegraf 1.19 - statsd plugin stops processing after receiving malformed stats

[blamarvt]

Relevant telegraf.conf:

[[inputs.statsd]]
# Anything 

System info:

Ubuntu 18.04 LTS
telegraf - 1.19.0-1

Docker

Not applicable

Steps to reproduce:

1. Start telegraf using a statsd input.
2. Send malformed stats to port 8125

#!/bin/bash
echo "test.service.stat.missing_value:|h" | nc -w 1 -u telegraf.server.local 8125

Expected behavior:

In previous versions of telegraf this error would happen:

2021-06-23T14:34:05Z E! [inputs.statsd] Parsing value to float64, unable to parse metric: test.service.stat.missing_value:|h

Actual behavior:

2021-06-23T14:40:15Z E! [inputs.statsd] Parsing value to float64, unable to parse metric: test.service.stat.missing_value:|h
2021-06-23T14:40:15Z E! [inputs.statsd] Error in plugin: error parsing statsd line
2021-06-23T14:40:15Z E! [inputs.statsd] Parsing value to float64, unable to parse metric: test.service.stat.missing_value:|h
2021-06-23T14:40:15Z E! [inputs.statsd] Error in plugin: error parsing statsd line
2021-06-23T14:40:15Z E! [inputs.statsd] Parsing value to float64, unable to parse metric: test.service.stat.missing_value:|h
2021-06-23T14:40:15Z E! [inputs.statsd] Error in plugin: error parsing statsd line
2021-06-23T14:40:25Z E! [inputs.statsd] Parsing value to float64, unable to parse metric: test.service.stat.missing_value:|h
2021-06-23T14:40:25Z E! [inputs.statsd] Error in plugin: error parsing statsd line
2021-06-23T14:40:25Z E! [inputs.statsd] Parsing value to float64, unable to parse metric: test.service.stat.missing_value:|h
2021-06-23T14:40:25Z E! [inputs.statsd] Error in plugin: error parsing statsd line
2021-06-23T14:42:47Z E! [inputs.statsd] Statsd message queue full. We have dropped 1 messages so far. You may want to increase allowed_pending_messages in the config

Additional info:

This section of code was added as part of PR #8992:

• telegraf/plugins/inputs/statsd/statsd.go

  Lines 570 to 572 in 8e7da35

  	if err := s.parseStatsdLine(line); err != nil {
  	return err
  	}

This causes the parser goroutine loop...

telegraf/plugins/inputs/statsd/statsd.go

Lines 444 to 453 in 8e7da35

	for i := 1; i <= parserGoRoutines; i++ {
	// Start the line parser
	s.wg.Add(1)
	go func() {
	defer s.wg.Done()
	if err := s.parser(); err != nil {
	ac.AddError(err)
	}
	}()
	}

... to exit which causes the input channel to fill up (as no statsd stats will be processed until the service gets restarted).