tumult-process — Process Chaos

Script-based plugin for process kill, suspend, and resume operations.

Actions

Action	Description	Key Variables
kill-process	Kill by PID, name, or pattern	TUMULT_PID, TUMULT_NAME, TUMULT_PATTERN, TUMULT_SIGNAL
suspend-process	Freeze (SIGSTOP)	TUMULT_PID, TUMULT_NAME, TUMULT_PATTERN
resume-process	Resume (SIGCONT)	TUMULT_PID, TUMULT_NAME, TUMULT_PATTERN

Target resolution priority: TUMULT_PID > TUMULT_NAME > TUMULT_PATTERN (first match wins).

Probes

Probe	Description	Output
process-exists	Is the process running?	true or false
process-resources	CPU and memory usage	JSON: {"cpu_percent": N, "mem_percent": N, "running": bool}

Example Experiment

steady_state_hypothesis:
  title: API process is running
  probes[1]:
    - name: api-alive
      activity_type: probe
      provider:
        type: process
        path: plugins/tumult-process/probes/process-exists.sh
        env:
          TUMULT_NAME: api-server
      tolerance:
        type: exact
        value: true

method[1]:
  - name: kill-api
    activity_type: action
    provider:
      type: process
      path: plugins/tumult-process/actions/kill-process.sh
      env:
        TUMULT_NAME: api-server
        TUMULT_SIGNAL: TERM
    pause_after_s: 5.0

rollbacks[1]:
  - name: restart-api
    activity_type: action
    provider:
      type: process
      path: systemctl
      arguments[2]: start, api-server

Works via SSH

All process plugin scripts work both locally and on remote hosts via ExecutionTarget::Ssh. The scripts use standard POSIX commands (kill, pkill, pgrep, ps) available on all Linux/macOS systems.