Simulate slow I/O operations.

Intercepts I/O operations and adds artificial delay, useful for testing behavior under slow disk, database, or external service conditions.

Configuration

• :delay_ms - Delay to add to each I/O operation (default: 100ms)
• :jitter_ms - Random jitter ± this value (default: 0)
• :target - What to slow: :all, :reads, :writes (default: :all)
• :duration_ms - How long the slowdown persists (default: 5000ms)

Usage

This nemesis sets a flag that your adapter should check:

defmodule MyAdapter do
  def read_file(path) do
    # Check for slow I/O nemesis
    if PropertyDamage.Nemesis.SlowIO.should_delay?(:reads) do
      PropertyDamage.Nemesis.SlowIO.apply_delay()
    end

    File.read(path)
  end
end

Example

def commands do
  [
    {ReadDocument, weight: 5},
    {WriteDocument, weight: 5},
    {PropertyDamage.Nemesis.SlowIO, weight: 1}
  ]
end

Testing Behavior

With slow I/O, your system should:

• Handle timeouts appropriately
• Not block user-facing operations
• Maintain consistency despite delays