Linux time chaos

Linux time chaos injects chaos to change the time of the Linux machine.

Use cases

• Induces time chaos to change the system time on the target Linux machines.
• Determines the resiliency of the underlying application components when subjected to a change in the system time.

note

• This fault can be executed on Ubuntu 16 or higher, Debian 10 or higher, CentOS 7 or higher, RHEL 7 or higher, Fedora 30 or higher, and openSUSE LEAP 15.4 or higher.
• The linux-chaos-infrastructure systemd service should be in an active state, and the infrastructure should be in CONNECTED state.

Fault permissions

The fault uses the root Linux user and root user group.

Fault tunables

Optional tunables

Tunable	Description	Notes
offset	Time offset to increment or decrement the system time. Should be provided in (+/-)[numeric-hours]h[numeric-minutes]m[numeric-seconds]s format.	For example: +24h, -13h12m, -3h12m16s
disableNTP	Set it to disable the NTP server.	Defaults to true
duration	Duration through which chaos is injected into the target resource (in seconds).	Default: 30s
rampTime	Period to wait before and after injecting chaos (in seconds).	Default: 0s

Offset

The offset input variable increments and decrements the system time using time offset. It is specified in (+/-)[numeric-hours]h[numeric-minutes]m[numeric-seconds]s format.

The following YAML snippet illustrates the use of this environment variable:

# time offset
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-time-chaos
  labels:
    name: time-chaos
spec:
  timeChaos/inputs:
    offset: '+1h30m'

DisableNTP

The disableNTP input variable prevents the fault from disabling the NTP server.

The following YAML snippet illustrates the use of this environment variable:

# disable the ntp server
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-time-chaos
  labels:
    name: time-chaos
spec:
  timeChaos/inputs:
    disableNTP: 'true'