Fluentd Keepalive Bug

docker-compose.yml

version: "3.7"
services:
  src:
    build:
      context: .
      dockerfile: src.Dockerfile

  dst:
    build:
      context: .
      dockerfile: dst.Dockerfile
    container_name: dst

dst.conf

<source>
	@type forward
	port 24224
  bind 0.0.0.0

	<security>
		self_hostname host2
		shared_key mysecret
	</security>
</source>

<match **>
	@type stdout
</match>

dst.Dockerfile

FROM fluent/fluentd:v1.5-debian
COPY dst.conf /fluentd/etc/fluent.conf

src.conf

<source>
  @type exec
  tag system.loadavg
  command cat /proc/loadavg | cut -d ' ' -f 1,2,3
  run_interval 5s
  <parse>
    @type tsv
    keys avg1,avg5,avg15
    delimiter " "
  </parse>
</source>

<match **>
	@type forward
	keepalive true

	<server>
		host dst
		port 24224
	</server>

	<security>
    self_hostname host1
		shared_key mysecret
	</security>

	<buffer>
		flush_interval 5s
		total_limit_size 64m
	</buffer>
</match>

src.Dockerfile

FROM fluent/fluentd:v1.5-debian
COPY src.conf /fluentd/etc/fluent.conf