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Version: 2.6.3

Simulate Time Faults

This document describes how to use Chaosd to simulate a time offset scenario. You can create experiments either in command-line mode or service mode.

Create experiments using command-line mode

This section describes how to create time fault experiments using commands.

Before creating an experiment, you can run the following command to check the options of time faults:

chaosd attack clock -h

The result is as follows:

$ chaosd attack clock -h

clock skew

chaosd attack clock attack [flags]

-c, --clock-ids-slice string The identifier of the particular clock on which to act.More clock description in linux kernel can be found in man page of clock_getres, clock_gettime, clock_settime.Muti clock ids should be split with "," (default "CLOCK_REALTIME")
-h, --help help for clock
-p, --pid int Pid of target program.
-t, --time-offset string Specifies the length of time offset.

Global Flags:
--log-level string the log level of chaosd, the value can be 'debug', 'info', 'warn' and 'error'
--uid string the experiment ID

Quick Example

Prepare test program:

cat > time.c << EOF
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <sys/types.h>

int main() {
printf("PID : %ld\n", (long)getpid());
struct timespec ts;
for(;;) {
clock_gettime(CLOCK_REALTIME, &ts);
printf("Time : %lld.%.9ld\n", (long long)ts.tv_sec, ts.tv_nsec);

gcc -o get_time ./time.c

Then execute get_time and try to attack it. The following is an example:

chaosd attack clock -p $PID -t 11s

Configurations of simulating time faults

ParameterTypeNoteDefault valueRequiredExample
timeOffsetstringSpecifies the length of time offset.NoneYes-5m
clockIds[]stringSpecifies the ID of clock that will be offset. See the clock_gettime documentation for details.["CLOCK_REALTIME"]No["CLOCK_REALTIME", "CLOCK_MONOTONIC"]
pidstringThe identifier of the process.NoneYes1

Create experiments using service mode

(ongoing update)