Many zombie processes into cadvisor container

[rc5hack]

After upgrading cadvisor from v0.47.2 to v0.49.1, I found huge number of zombie processes running on the server. After cadvisor stop, they disappear.

Is it normal or not?

root@media:/opt/cadvisor$ ps auxww | grep -F -c ' Z'
17611

root@media:/opt/cadvisor$ ps auxww | grep -F ' Z' | tail
root     4192204  0.0  0.0      0     0 ?        Zs   Apr18   0:00 [timeout] <defunct>
root     4192490  0.0  0.0      0     0 ?        Zs   Apr16   0:00 [timeout] <defunct>
root     4192629  0.0  0.0      0     0 ?        Zs   Apr18   0:00 [timeout] <defunct>
root     4192942  0.0  0.0      0     0 ?        Zs   Apr16   0:00 [timeout] <defunct>
root     4193064  0.0  0.0      0     0 ?        Zs   Apr18   0:00 [timeout] <defunct>
root     4193399  0.0  0.0      0     0 ?        Zs   Apr16   0:00 [timeout] <defunct>
root     4193440  0.0  0.0      0     0 ?        Zs   Apr18   0:00 [timeout] <defunct>
root     4193810  0.0  0.0      0     0 ?        Zs   Apr16   0:00 [timeout] <defunct>
root     4193887  0.0  0.0      0     0 ?        Zs   Apr18   0:00 [timeout] <defunct>
root     4194260  0.0  0.0      0     0 ?        Zs   Apr16   0:00 [timeout] <defunct>

root@media:/opt/cadvisor$ pstree -p -s 4194260
systemd(1)───containerd-shim(2009543)───cadvisor(2009562)───timeout(4194260)

root@media:/opt/cadvisor$ docker compose down
[+] Running 2/2
 ✔ Container cadvisor                    Removed                                                                                                       1.7s
 ✔ Network docker-host-cadvisor_default  Removed                                                                                                       0.3s

root@media:/opt/cadvisor$ ps auxww | grep -F -c ' Z'
1

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 22.04.4 LTS
Release:        22.04
Codename:       jammy

$ uname -r
5.15.0-100-generic

docker-compose.yml:

version: '2.4'
name: docker-host-cadvisor
services:
  cadvisor:
    container_name: cadvisor
    hostname: cadvisor
    image: gcr.io/cadvisor/cadvisor:v0.49.1
    volumes:
      - ./cadvisor.htpasswd:/opt/cadvisor.htpasswd:ro
      - /:/rootfs:ro
      - /var/run:/var/run:ro
      - /sys:/sys:ro
      - /var/lib/docker/:/var/lib/docker:ro
      - /dev/disk/:/dev/disk:ro
    devices:
      - /dev/kmsg
    privileged: true
    command:
      - --http_auth_file=/opt/cadvisor.htpasswd
      - --http_auth_realm=cadv
      - --prometheus_endpoint=/cadvisor_metrics_random_string_here # see https://github.com/google/cadvisor/issues/3401
      - --housekeeping_interval=5s
      - --disable_metrics=advtcp,app,cpu_topology,cpuset,disk,diskIO,hugetlb,memory_numa,percpu,process,referenced_memory,resctrl,sched,tcp,udp
      - --docker_only=true
    ports:
      - 0.0.0.0:9999:8080
    restart: unless-stopped
    cpus: 0.50
    mem_limit: 768m
    healthcheck:
      test: timeout 2 wget -q -t1 -O- http://localhost:8080/cadvisor_metrics_random_string_here | grep cadvisor_version_info
      interval: 20s
      retries: 3
      start_period: 10s
      timeout: 5s
    logging:
      driver: "json-file"
      options:
        max-size: "128m"
        max-file: "4"