If the shutdown and startup are timed correctly, a zombie listen port will be created

If a container with a listen port is started immediately after it is stopped, it cannot be started and the listen port will remain.
I have uploaded the verification video to youtube.
Thanks for your help,

   lxc info --show-log c1
Name: c1
Location: none
Remote: unix://
Architecture: x86_64
Created: 2021/06/21 04:04 UTC
Status: Running
Type: container
Profiles: default
Pid: 16395
Ips:
lo:   inet    127.0.0.1
lo:   inet6   ::1
eth0: inet    10.58.160.215   veth39aeb650
eth0: inet6   fd42:3ece:a9d9:7476:216:3eff:fe62:8924  veth39aeb650
eth0: inet6   fe80::216:3eff:fe62:8924        veth39aeb650
Resources:
Processes: 40
Disk usage:
    root: 22.35MB
CPU usage:
    CPU usage (in seconds): 6
Memory usage:
    Memory (current): 131.38MB
    Memory (peak): 168.90MB
Network usage:
    eth0:
    Bytes received: 12.30kB
    Bytes sent: 5.73kB
    Packets received: 48
    Packets sent: 50
    lo:
    Bytes received: 1.04kB
    Bytes sent: 1.04kB
    Packets received: 12
    Packets sent: 12

Log:

lxc c1 20210621040651.271 ERROR    utils - utils.c:lxc_can_use_pidfd:1772 - Kernel does not support pidfds
lxc c1 20210621040651.271 WARN     conf - conf.c:lxc_map_ids:3007 - newuidmap binary is missing
lxc c1 20210621040651.271 WARN     conf - conf.c:lxc_map_ids:3013 - newgidmap binary is missing
lxc c1 20210621040651.273 WARN     conf - conf.c:lxc_map_ids:3007 - newuidmap binary is missing
lxc c1 20210621040651.274 WARN     conf - conf.c:lxc_map_ids:3013 - newgidmap binary is missing
lxc c1 20210621040651.274 WARN     cgfsng - cgroups/cgfsng.c:fchowmodat:1293 - No such file or directory - Failed to fchownat(41, memory.oom.group, 65536, 0, AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW )

@penM000 what LXD version is that?

Its at the end of the video:

LXD 4.15
Kernel 4.19 Debian

@tomp can you try to reproduce it and see what’s going on? This may match what we’ve seen on and off on the forum.

Yep will do.

Sorry. I forgot to describe the environment as a sentence.
Here is the result of lxc info.
There is no video, but I have also confirmed the phenomenon on Ubuntu 20.04.2 LTS (lxd 4.15).

server@server1:~$ lxc info
config:
core.https_address: '[::]'
core.trust_password: true
api_extensions:
- storage_zfs_remove_snapshots
- container_host_shutdown_timeout
- container_stop_priority
- container_syscall_filtering
- auth_pki
- container_last_used_at
- etag
- patch
- usb_devices
- https_allowed_credentials
- image_compression_algorithm
- directory_manipulation
- container_cpu_time
- storage_zfs_use_refquota
- storage_lvm_mount_options
- network
- profile_usedby
- container_push
- container_exec_recording
- certificate_update
- container_exec_signal_handling
- gpu_devices
- container_image_properties
- migration_progress
- id_map
- network_firewall_filtering
- network_routes
- storage
- file_delete
- file_append
- network_dhcp_expiry
- storage_lvm_vg_rename
- storage_lvm_thinpool_rename
- network_vlan
- image_create_aliases
- container_stateless_copy
- container_only_migration
- storage_zfs_clone_copy
- unix_device_rename
- storage_lvm_use_thinpool
- storage_rsync_bwlimit
- network_vxlan_interface
- storage_btrfs_mount_options
- entity_description
- image_force_refresh
- storage_lvm_lv_resizing
- id_map_base
- file_symlinks
- container_push_target
- network_vlan_physical
- storage_images_delete
- container_edit_metadata
- container_snapshot_stateful_migration
- storage_driver_ceph
- storage_ceph_user_name
- resource_limits
- storage_volatile_initial_source
- storage_ceph_force_osd_reuse
- storage_block_filesystem_btrfs
- resources
- kernel_limits
- storage_api_volume_rename
- macaroon_authentication
- network_sriov
- console
- restrict_devlxd
- migration_pre_copy
- infiniband
- maas_network
- devlxd_events
- proxy
- network_dhcp_gateway
- file_get_symlink
- network_leases
- unix_device_hotplug
- storage_api_local_volume_handling
- operation_description
- clustering
- event_lifecycle
- storage_api_remote_volume_handling
- nvidia_runtime
- container_mount_propagation
- container_backup
- devlxd_images
- container_local_cross_pool_handling
- proxy_unix
- proxy_udp
- clustering_join
- proxy_tcp_udp_multi_port_handling
- network_state
- proxy_unix_dac_properties
- container_protection_delete
- unix_priv_drop
- pprof_http
- proxy_haproxy_protocol
- network_hwaddr
- proxy_nat
- network_nat_order
- container_full
- candid_authentication
- backup_compression
- candid_config
- nvidia_runtime_config
- storage_api_volume_snapshots
- storage_unmapped
- projects
- candid_config_key
- network_vxlan_ttl
- container_incremental_copy
- usb_optional_vendorid
- snapshot_scheduling
- snapshot_schedule_aliases
- container_copy_project
- clustering_server_address
- clustering_image_replication
- container_protection_shift
- snapshot_expiry
- container_backup_override_pool
- snapshot_expiry_creation
- network_leases_location
- resources_cpu_socket
- resources_gpu
- resources_numa
- kernel_features
- id_map_current
- event_location
- storage_api_remote_volume_snapshots
- network_nat_address
- container_nic_routes
- rbac
- cluster_internal_copy
- seccomp_notify
- lxc_features
- container_nic_ipvlan
- network_vlan_sriov
- storage_cephfs
- container_nic_ipfilter
- resources_v2
- container_exec_user_group_cwd
- container_syscall_intercept
- container_disk_shift
- storage_shifted
- resources_infiniband
- daemon_storage
- instances
- image_types
- resources_disk_sata
- clustering_roles
- images_expiry
- resources_network_firmware
- backup_compression_algorithm
- ceph_data_pool_name
- container_syscall_intercept_mount
- compression_squashfs
- container_raw_mount
- container_nic_routed
- container_syscall_intercept_mount_fuse
- container_disk_ceph
- virtual-machines
- image_profiles
- clustering_architecture
- resources_disk_id
- storage_lvm_stripes
- vm_boot_priority
- unix_hotplug_devices
- api_filtering
- instance_nic_network
- clustering_sizing
- firewall_driver
- projects_limits
- container_syscall_intercept_hugetlbfs
- limits_hugepages
- container_nic_routed_gateway
- projects_restrictions
- custom_volume_snapshot_expiry
- volume_snapshot_scheduling
- trust_ca_certificates
- snapshot_disk_usage
- clustering_edit_roles
- container_nic_routed_host_address
- container_nic_ipvlan_gateway
- resources_usb_pci
- resources_cpu_threads_numa
- resources_cpu_core_die
- api_os
- container_nic_routed_host_table
- container_nic_ipvlan_host_table
- container_nic_ipvlan_mode
- resources_system
- images_push_relay
- network_dns_search
- container_nic_routed_limits
- instance_nic_bridged_vlan
- network_state_bond_bridge
- usedby_consistency
- custom_block_volumes
- clustering_failure_domains
- resources_gpu_mdev
- console_vga_type
- projects_limits_disk
- network_type_macvlan
- network_type_sriov
- container_syscall_intercept_bpf_devices
- network_type_ovn
- projects_networks
- projects_networks_restricted_uplinks
- custom_volume_backup
- backup_override_name
- storage_rsync_compression
- network_type_physical
- network_ovn_external_subnets
- network_ovn_nat
- network_ovn_external_routes_remove
- tpm_device_type
- storage_zfs_clone_copy_rebase
- gpu_mdev
- resources_pci_iommu
- resources_network_usb
- resources_disk_address
- network_physical_ovn_ingress_mode
- network_ovn_dhcp
- network_physical_routes_anycast
- projects_limits_instances
- network_state_vlan
- instance_nic_bridged_port_isolation
- instance_bulk_state_change
- network_gvrp
- instance_pool_move
- gpu_sriov
- pci_device_type
- storage_volume_state
- network_acl
- migration_stateful
- disk_state_quota
- storage_ceph_features
- projects_compression
- projects_images_remote_cache_expiry
- certificate_project
- network_ovn_acl
- projects_images_auto_update
- projects_restricted_cluster_target
- images_default_architecture
- network_ovn_acl_defaults
- gpu_mig
- project_usage
- network_bridge_acl
- warnings
- projects_restricted_backups_and_snapshots
- clustering_join_token
- clustering_description
- server_trusted_proxy
api_status: stable
api_version: "1.0"
auth: trusted
public: false
auth_methods:
- tls
environment:
addresses:
architectures:
- x86_64
- i686
certificate: |
    -----BEGIN CERTIFICATE-----

    -----END CERTIFICATE-----
certificate_fingerprint: 
driver: qemu | lxc
driver_version: 5.2.0 | 4.0.9
firewall: xtables
kernel: Linux
kernel_architecture: x86_64
kernel_features:
    netnsid_getifaddrs: "false"
    seccomp_listener: "false"
    seccomp_listener_continue: "false"
    shiftfs: "false"
    uevent_injection: "true"
    unpriv_fscaps: "true"
kernel_version: 4.19.0-17-amd64
lxc_features:
    cgroup2: "true"
    devpts_fd: "true"
    idmapped_mounts_v2: "false"
    mount_injection_file: "true"
    network_gateway_device_route: "true"
    network_ipvlan: "true"
    network_l2proxy: "true"
    network_phys_macvlan_mtu: "true"
    network_veth_router: "true"
    pidfd: "true"
    seccomp_allow_deny_syntax: "true"
    seccomp_notify: "true"
    seccomp_proxy_send_notify_fd: "true"
os_name: Debian GNU/Linux
os_version: "10"
project: default
server: lxd
server_clustered: false
server_name: server1
server_pid: 2118
server_version: "4.15"
storage: zfs
storage_version: 2.0.3-1~bpo10+1

Thanks.

Yes I’ve recreated the issue with this in one terminal:

#!/bin/bash
for i in {1..100}; do
	lxc start c1
done

and this is another

lxc exec c1 -- shutdown now

The root of the problem is that container stop and start operations are overlapping, preventing the stop hook clean up from the original running container from running:

INFO[06-21|09:48:58] Starting container                       instanceType=container instance=c1 project=test action=start created=2021-06-21T09:43:25+0100 ephemeral=false used=2021-06-21T09:47:44+0100 stateful=false
EROR[06-21|09:48:58] The stop hook failed                     instance=c1 err="Container is already running a start operation"
DBUG[06-21|09:48:58] 
	{
		"error": "Container is already running a start operation",
		"error_code": 500,
		"type": "error"
	} 

This should fix it:

1 Like

I have one container (it runs my Plex media server) that seems to go a bit rogue over the last couple of weeks. Things I see:

  1. Plex is unresponsive
  2. The load average is a bit higher on my server, sitting about 5 instead of 2-3.
  3. Within the container, try to restart Plex - doesn’t work.
  4. Within the container, try and execute a reboot - doesn’t appear to work.
  5. From the host, try to stop the container - runs infinitely. Ctrl+C 3 times to go back to the prompt.
  6. lxc list shows that the container is running but no IP address.
  7. Can no longer get to a container bash prompt (lxc exec plex bash)
  8. lxc info brought me here:
djwhyte@server1:~$ lxc info --show-log plex
Name: plex
Location: none
Remote: unix://
Architecture: x86_64
Created: 2021/06/06 12:50 UTC
Status: Running
Type: container
Profiles: default
Pid: 3732
Resources:
  Processes: 4
  Disk usage:
    root: 15.57GB
  CPU usage:
    CPU usage (in seconds): 28321
  Memory usage:
    Memory (current): 213.93MB
    Memory (peak): 9.36GB
Snapshots:
  snap0 (taken at 2021/06/15 11:41 UTC) (stateless)

Log:

lxc plex 20210704111427.962 WARN     conf - conf.c:lxc_map_ids:3007 - newuidmap binary is missing
lxc plex 20210704111427.963 WARN     conf - conf.c:lxc_map_ids:3013 - newgidmap binary is missing
lxc plex 20210704111842.627 WARN     conf - conf.c:lxc_map_ids:3007 - newuidmap binary is missing
lxc plex 20210704111842.627 WARN     conf - conf.c:lxc_map_ids:3013 - newgidmap binary is missing
lxc plex 20210704112147.244 WARN     conf - conf.c:lxc_map_ids:3007 - newuidmap binary is missing
lxc plex 20210704112147.244 WARN     conf - conf.c:lxc_map_ids:3013 - newgidmap binary is missing

Running LXD 4.0.6 from snap.

Only fix ends up being a host reboot. :frowning:

Will the above fix rectify this issue? Or should I be looking elsewhere? Anything else I can do?

Cheers,
Whytey

No that sounds entirely unrelated.

Did you try using the ‘–force’ or ‘-f’ flag with ‘lxc stop’ that is how you stop an unresponsive instance.

Hi Tom,

I am pretty sure I tried that a couple of weeks ago to no effect. Unfortunately, I have done a server reboot so can’t try now.

Of note, the server reboot takes forever, something causes things to get terribly locked up!

I expect you want me to start a new thread here or issue on GitHub for it?

Cheers,
Whytey

Yes a new thread would be good. It doesn’t look like LXD is causing the delay in shutdown in that image, but the network service, so might not be LXD related.

Thank you for fixing this in lxd4.16!

1 Like