Lack of debug logs on Filebeat kafka output

[Steve_McDuff]

While using filebeat, I encountered an odd issue where two servers configured with the same way behaved very differently. One of them works perfectly fine and the other one works at a very slow pace. So I know the problem lies somewhere in the infrastructure and not on filebeat.

While comparing the slow and fast server, I noticed differences in the following metrics:

monitoring.metrics.libbeat.output.events.active : 4000 on the slow server, sub 10 on the fast one.
monitoring.metrics.libbeat.output.events.failed : 4000 on the slow server, zero on the fast one.

To troubleshoot this issue, I turned on all the debug logs for a few minutes by running :

filebeat -e -d "*"

Reading through the entire debug logs, I couldn't find any clue to tell me why some events reached the failed state.

Hence my questions :

• Did I miss a configuration flag to enable Kafka output debug logs ?
• If not, should Kafka output generate logs when messages reach the failed status ?

Here is the full metrics output of the slow server :

{
	"monitoring": {
		"metrics": {
			"beat": {
				"cgroup": {
					"memory": {
						"mem": {
							"usage": {
								"bytes": 139218944
							}
						}
					}
				},
				"cpu": {
					"system": {
						"ticks": 590,
						"time": {
							"ms": 36
						}
					},
					"total": {
						"ticks": 3380,
						"time": {
							"ms": 233
						},
						"value": 3380
					},
					"user": {
						"ticks": 2790,
						"time": {
							"ms": 197
						}
					}
				},
				"handles": {
					"limit": {
						"hard": 1000000,
						"soft": 1000000
					},
					"open": 21
				},
				"info": {
					"ephemeral_id": "0914acdc-9743-41ef-9819-bed28d68f8b3",
					"uptime": {
						"ms": 540080
					},
					"version": "7.14.1"
				},
				"memstats": {
					"gc_next": 66830880,
					"memory_alloc": 57164504,
					"memory_total": 228143544,
					"rss": 145899520
				},
				"runtime": {
					"goroutines": 90
				}
			},
			"filebeat": {
				"harvester": {
					"open_files": 1,
					"running": 1
				}
			},
			"libbeat": {
				"config": {
					"module": {
						"running": 0
					}
				},
				"output": {
					"events": {
						"acked": 46,
						"active": 3905,
						"batches": 2,
						"failed": 3905,
						"total": 3905
					}
				},
				"outputs": {
					"kafka": {
						"bytes_read": 56346,
						"bytes_write": 175304
					}
				},
				"pipeline": {
					"clients": 1,
					"events": {
						"active": 4117,
						"retry": 3905
					}
				}
			},
			"registrar": {
				"states": {
					"current": 1
				}
			},
			"system": {
				"load": {
					"1": 2.94,
					"15": 3.46,
					"5": 3.31,
					"norm": {
						"1": 0.3675,
						"15": 0.4325,
						"5": 0.4138
					}
				}
			}
		}
	}
}

Here is the Filebeat configuration:

filebeat.inputs:
- type: log
  enabled: true
  paths:
    - /mongo/shard_*/mongo.log
  scan_frequency: 5s
  clean_removed: true
  close_removed: true
  close_renamed: true
  max_bytes: 2000000
  fields_under_root: true
  fields:
    type: mongo-shard
    local_timezone: UTC
    role: mongod
  multiline:
    pattern: ^[0-9]{1,}-[0-9]{1,}-[0-9]{1,}T[0-9]{1,}:[0-9]{1,}:[0-9]{1,}.[0-9]{1,}
    negate: true
    match: after
    max_lines: 5000
    timeout: 5s

output.kafka:
  enabled: true
  hosts: ['myhost:9096']
  username: ${MYUSER}
  password: ${MYPASSWORD}
  sasl.mechanism: SCRAM-SHA-256
  ssl.enabled: true
  topic: mytopic
  partition.round_robin:
    reachable_only: false
  required_acks: 1
  compression: gzip
  max_message_bytes: 1000000

path.data: /mongo/filebeat/data
path.logs: /mongo/filebeat/logs