PropertyDamage.Nemesis.NetworkLatency (PropertyDamage v0.2.0)

Inject network latency into the test environment.

Simulates slow network conditions by adding delay to network operations. Useful for testing timeout handling, retry logic, and degraded performance.

Configuration

• :latency_ms - Base latency to add (default: 100ms)
• :jitter_ms - Random jitter ± this value (default: 0)
• :duration_ms - How long the latency persists (default: 5000ms)
• :target - What to affect: :all, :upstream, :downstream, or specific host

Usage with Toxiproxy

When using Toxiproxy, set :toxiproxy in the adapter context:

context = %{toxiproxy: %{proxy_name: "my_service", api_url: "http://localhost:8474"}}

Simulated Mode

Without Toxiproxy, operates in simulated mode where latency is tracked in state but not actually injected. Useful for testing nemesis logic.

Example

defmodule MyModel do
  def commands do
    [
      {CreateOrder, weight: 5},
      {PropertyDamage.Nemesis.NetworkLatency, weight: 1}  # Low weight for chaos
    ]
  end
end

Events

Emits %NetworkLatencyInjected{} on inject and %NetworkLatencyRestored{} on restore.