@spec cascading_failure_scenario(
  device_list(),
  keyword()
) :: scenario_result()

Simulate cascading failure - devices fail in sequence.

Models scenarios where initial failures trigger subsequent failures, testing system resilience under escalating conditions.

Options

• initial_failure_percentage: Initial devices that fail (default: 0.1)
• cascade_delay_seconds: Time between cascade waves (default: 60)
• cascade_growth_factor: How much each wave grows (default: 1.5)
• max_affected_percentage: Maximum devices affected (default: 0.8)

Examples

# Start with 5% failure, cascade every 30 seconds
TestScenarios.cascading_failure_scenario(devices,
  initial_failure_percentage: 0.05,
  cascade_delay_seconds: 30,
  cascade_growth_factor: 2.0
)

@spec device_flapping_scenario(
  device_list(),
  keyword()
) :: scenario_result()

Simulate device flapping - intermittent connectivity issues.

Models unstable devices that repeatedly go offline and come back online.

Options

• flap_interval_seconds: Time between state changes (default: 30)
• down_duration_seconds: How long device stays down (default: 10)
• total_duration_minutes: Total scenario duration (default: 30)

• flap_pattern: :regular | :irregular | :degrading (default: :irregular)

Examples

# Regular flapping every 60 seconds
TestScenarios.device_flapping_scenario(devices,
  flap_interval_seconds: 60,
  down_duration_seconds: 15,
  flap_pattern: :regular
)

# Irregular flapping with degrading stability
TestScenarios.device_flapping_scenario(devices,
  flap_pattern: :degrading,
  total_duration_minutes: 45
)

@spec environmental_scenario(
  device_list(),
  keyword()
) :: scenario_result()

Simulate environmental conditions affecting network equipment.

Models weather, power, or temperature-related issues that affect multiple devices simultaneously.

Options

• condition_type: :weather | :power | :temperature | :interference

• severity: :mild | :moderate | :severe (default: :moderate)

• duration_hours: Condition duration (default: 2)

• geographic_pattern: :random | :clustered | :linear (default: :clustered)

Examples

# Severe weather affecting clustered devices
TestScenarios.environmental_scenario(devices,
  condition_type: :weather,
  severity: :severe,
  duration_hours: 4,
  geographic_pattern: :clustered
)

# Power instability
TestScenarios.environmental_scenario(devices,
  condition_type: :power,
  severity: :moderate,
  duration_hours: 1
)

@spec high_load_scenario(
  device_list(),
  keyword()
) :: scenario_result()

Simulate high network load and congestion conditions.

Tests poller behavior under network stress with increased latency, packet loss, and timeout conditions.

Options

• utilization_percent: Network utilization level (default: 85)
• duration_minutes: Load duration (default: 60)

• congestion_type: :steady | :bursty | :cascade (default: :bursty)

• error_rate_multiplier: Error rate increase factor (default: 5.0)

Examples

# Sustained high load
TestScenarios.high_load_scenario(devices,
  utilization_percent: 95,
  duration_minutes: 120,
  congestion_type: :steady
)

# Bursty congestion with high error rates
TestScenarios.high_load_scenario(devices,
  utilization_percent: 90,
  congestion_type: :bursty,
  error_rate_multiplier: 10.0
)

@spec multi_scenario_test(device_list(), [{atom(), keyword()}]) :: [scenario_result()]

Apply multiple scenarios simultaneously for complex testing.

Combines different failure patterns to test system behavior under realistic multi-factor conditions.

Examples

scenarios = [
  {:signal_degradation, [snr_degradation: 8, duration_minutes: 60]},
  {:high_load, [utilization_percent: 90, duration_minutes: 45]},
  {:device_flapping, [flap_interval_seconds: 120]}
]

TestScenarios.multi_scenario_test(devices, scenarios)

@spec network_outage_scenario(
  device_list(),
  keyword()
) :: scenario_result()

Simulate complete network outage affecting all devices.

Tests poller behavior during total connectivity loss and recovery.

Options

• duration_seconds: Outage duration (default: 300)

• recovery_type: :immediate | :gradual | :sporadic (default: :gradual)

• affected_percentage: Percentage of devices affected (default: 1.0)

Examples

# 5-minute complete outage
TestScenarios.network_outage_scenario(devices, duration_seconds: 300)

# Gradual recovery affecting 80% of devices
TestScenarios.network_outage_scenario(devices,
  duration_seconds: 600,
  recovery_type: :gradual,
  affected_percentage: 0.8
)

@spec signal_degradation_scenario(
  device_list(),
  keyword()
) :: scenario_result()

Simulate signal degradation for wireless/cable devices.

Models weather-related signal issues, interference, or equipment problems.

Options

• snr_degradation: SNR reduction in dB (default: 5)
• power_variation: Power level variation in dBmV (default: 3)
• duration_minutes: Degradation duration (default: 30)

• pattern: :steady | :fluctuating | :progressive (default: :fluctuating)

Examples

# Weather-related signal degradation
TestScenarios.signal_degradation_scenario(cable_modems,
  snr_degradation: 10,
  power_variation: 5,
  duration_minutes: 45,
  pattern: :progressive
)