---
title: Simulate Process Faults
sidebar_label: Simulate Process Faults
---

This document describes how to use Chaosd to simulate process faults. The process faults use the Golang interface of the kill command to simulate the scenarios that the process is killed or stopped. You can create experiments either in command-line mode or service mode.

## Create experiments in command-line mode

Before creating an experiment, you can run the following command to see the process fault types that are supported by Chaosd:

```bash
chaosd attack process -h
```

The output is as follows:

```bash
Process attack related commands

Usage:
  chaosd attack process [command]

Available Commands:
  kill        kill process, default signal 9
  stop        stop process, this action will stop the process with SIGSTOP

Flags:
  -h, --help   help for process

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

Use "chaosd attack process [command] --help" for more information about a command.
```

Currently, Chaosd supports simulating that a process is killed or stopped.

### Killing a process

#### Command simulating that a process is killed

```bash
chaosd attack process kill -h
```

The output is as follows:

```bash
kill process, default signal 9

Usage:
  chaosd attack process kill [flags]

Flags:
  -h, --help             help for kill
  -p, --process string   The process name or the process ID
  -s, --signal int       The signal number to send (default 9)

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

#### Configuration description of simulating a process being killed

| Configuration item | Abbreviation | Description                                                  | Value                                                                                     |
| :----------------- | :----------- | :------------------------------------------------------------ | :---------------------------------------------------------------------------------------- |
| process            | p            | The name or identifier of the process that needs to be killed | string; the default value is "".                                                          |
| signal             | s            | The provided value of the process signal                      | int; the default value is 9. Currently, only SIGKILL, SIGTERM, and SIGSTOP are supported. |

#### Example simulating that a process is killed

```bash
chaosd attack process kill python
```

The output is as follows:

```bash
chaosd attack process kill -p python
Attack process python successfully, uid: 10e633ac-0a37-41ba-8b4a-cd5ab92099f9
```

### Stopping a process

#### Command simulating that a process is stopped

```bash
chaosd attack process stop -h
```

The output is as follows:

```bash
stop process, this action will stop the process with SIGSTOP

Usage:
  chaosd attack process stop [flags]

Flags:
  -h, --help             help for stop
  -p, --process string   The process name or the process ID

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

#### Configuration description of simulating a process being stopped

| Configuration item | Abbreviation | Description                                                    | Value                            |
| :----------------- | :----------- | :------------------------------------------------------------- | :------------------------------- |
| process            | p            | The name or identifier of the process that needs to be stopped | string; the default value is "". |

#### Example simulating that a process is stopped

```bash
chaosd attack process stop python
```

The output is as follows:

```bash
chaosd attack process stop -p python
Attack process python successfully, uid: 9cb6b3be-4f5b-4ecb-ae05-51050fcd0010
```

## Create experiments in service mode

(To be added)