/// <summary>
/// If <see cref="JitterMaxDuration"/> is greater than <see cref="TimeSpan.Zero"/>, this method returns a randomized duration (in ms) between 0 and <see cref="JitterMaxDuration"/> that will be added to the entry's specified <see cref="Duration"/> .
/// This is done to avoid a variation of the so called <a href="https://en.wikipedia.org/wiki/Thundering_herd_problem">thundering herd problem</a> that may happen when the entry for the same key expires on multiple nodes at the same time, because of high synchronization.
/// </summary>
/// <returns>An additional cache duration (in ms) to slightly vary the entry duration</returns>
public double GetJitterDurationMs()
{
if (JitterMaxDuration <= TimeSpan.Zero)
{
return(0d);
}
return(ConcurrentRandom.NextDouble() * JitterMaxDuration.TotalMilliseconds);
}
/// <summary>
/// Randomize an actual delay with a value between <paramref name="minDelay"/> and <paramref name="maxDelay"/>.
/// </summary>
/// <param name="minDelay">The minimun amount of delay.</param>
/// <param name="maxDelay">The maximum amount of delay.</param>
/// <returns>The randomized delay.</returns>
public static TimeSpan RandomizeDelay(TimeSpan minDelay, TimeSpan maxDelay)
{
if (minDelay <= TimeSpan.Zero && maxDelay <= TimeSpan.Zero)
{
return(TimeSpan.Zero);
}
if (minDelay >= maxDelay)
{
return(minDelay);
}
return(minDelay + TimeSpan.FromMilliseconds(ConcurrentRandom.NextDouble() * (maxDelay - minDelay).TotalMilliseconds));
}
/// <summary>
/// Determines if an exception should be thrown.
/// </summary>
/// <param name="throwProbability">The probabilty that an exception will be thrown.</param>
/// <returns>True if an exception should be thrown, false otherwise.</returns>
public static bool ShouldCreateChaos(float throwProbability)
{
if (throwProbability <= 0f)
{
return(false);
}
if (throwProbability >= 1f)
{
return(true);
}
return(ConcurrentRandom.NextDouble() < throwProbability);
}