moby: docker stats does not show any information (only dashes)

This happens after some time (hour or two) of normal stats.

I’m having the same issue. I’m using docker stats through a Python script to collect CPU and memory usage of a container while a client sends requests so to analyze its behaviour. I’m reading some values correctly, then a lot of values get dashes for a long time. It looks like it gets better when the container is under high load, while it shows dashes frequently when the container is nearly idle.

I’m doing these tests on a Raspberry Pi 3 B with Raspbian.

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uname -a

Linux raspberrypi 5.10.63-v7+ #1496 SMP Wed Dec 1 15:58:11 GMT 2021 armv7l GNU/Linux

---

docker version

Client: Docker Engine - Community
 Version:           20.10.12
 API version:       1.41
 Go version:        go1.16.12
 Git commit:        e91ed57
 Built:             Mon Dec 13 11:45:14 2021
 OS/Arch:           linux/arm
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.12
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.16.12
  Git commit:       459d0df
  Built:            Mon Dec 13 11:43:32 2021
  OS/Arch:          linux/arm
  Experimental:     false
 containerd:
  Version:          1.4.12
  GitCommit:        7b11cfaabd73bb80907dd23182b9347b4245eb5d
 runc:
  Version:          1.0.2
  GitCommit:        v1.0.2-0-g52b36a2
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

---

docker info

Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Docker Buildx (Docker Inc., v0.7.1-docker)

Server:
 Containers: 5
  Running: 1
  Paused: 0
  Stopped: 4
 Images: 47
 Server Version: 20.10.12
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 7b11cfaabd73bb80907dd23182b9347b4245eb5d
 runc version: v1.0.2-0-g52b36a2
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 5.10.63-v7+
 Operating System: Raspbian GNU/Linux 10 (buster)
 OSType: linux
 Architecture: armv7l
 CPUs: 4
 Total Memory: 923.2MiB
 Name: raspberrypi
 ID: CLKG:2NVX:AVJE:T7SY:A36Q:R7K4:AD2K:EV6L:VVL5:CGFA:XCIP:CFAN
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

WARNING: No blkio throttle.read_bps_device support
WARNING: No blkio throttle.write_bps_device support
WARNING: No blkio throttle.read_iops_device support
WARNING: No blkio throttle.write_iops_device support

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EDIT: this behaviour is not observable on another machine (Arch Linux) on which I ran the same tests.

uname -a

Linux <hostname> 5.15.31-1-lts #1 SMP Wed, 23 Mar 2022 09:55:25 +0000 x86_64 GNU/Linux

---

docker version

Client:
 Version:           20.10.14
 API version:       1.41
 Go version:        go1.18
 Git commit:        a224086349
 Built:             Thu Mar 24 08:56:17 2022
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server:
 Engine:
  Version:          20.10.14
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.18
  Git commit:       87a90dc786
  Built:            Thu Mar 24 08:56:03 2022
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v1.6.2
  GitCommit:        de8046a5501db9e0e478e1c10cbcfb21af4c6b2d.m
 runc:
  Version:          1.1.1
  GitCommit:        
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

---

docker info

Client:
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc., v0.8.1-docker)
  compose: Docker Compose (Docker Inc., 2.4.0)

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 1
 Server Version: 20.10.14
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Native Overlay Diff: false
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: de8046a5501db9e0e478e1c10cbcfb21af4c6b2d.m
 runc version: 
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
  cgroupns
 Kernel Version: 5.15.31-1-lts
 Operating System: EndeavourOS
 OSType: linux
 Architecture: x86_64
 CPUs: 16
 Total Memory: 30.72GiB
 Name: <hostname>
 ID: VRFQ:VSYA:6JJN:666H:3WZ7:P65T:TBMB:SSDM:ZRD6:7JTF:LMNV:KUYO
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false