/// <summary>
/// Checks to see if the breaker should trip, and trips if it should.
/// </summary>
/// <returns><code>true</code> if breaker is tripped</returns>
private bool CheckAndSetTripped()
{
var stopwatch = Stopwatch.StartNew();
var state = "Unknown";
try
{
if (_state == State.Tripped)
{
state = "AlreadyTripped";
return(true);
}
if (!Monitor.TryEnter(_stateChangeLock))
{
state = "MissedLock";
return(_state == State.Tripped);
}
try
{
var snapshot = _metrics.GetSnapshot();
// If we haven't met the minimum number of operations needed to trip, don't trip.
if (snapshot.Total < Properties.MinimumOperations.Value)
{
state = "CriteriaNotMet";
return(false);
}
// If we're within the error threshold, don't trip.
if (snapshot.ErrorPercentage < Properties.ThresholdPercentage.Value)
{
state = "CriteriaNotMet";
return(false);
}
_state = State.Tripped;
_lastTrippedTimestamp = _clock.GetMillisecondTimestamp();
state = "JustTripped";
_stats.Event(StatsPrefix, State.Tripped.ToString(), null);
Log.ErrorFormat("Tripped Breaker={0} Operations={1} ErrorPercentage={2} Wait={3}",
_key,
snapshot.Total,
snapshot.ErrorPercentage,
Properties.TrippedDurationMillis.Value);
return(true);
}
finally
{
Monitor.Exit(_stateChangeLock);
}
}
finally
{
_stats.Elapsed(StatsPrefix + " CheckAndSetTripped", state, stopwatch.Elapsed);
}
}
/// <summary>
/// Checks to see if the breaker should trip, and trips if it should.
/// </summary>
/// <returns><code>true</code> if breaker is tripped</returns>
private bool CheckAndSetTripped()
{
if (_state == State.Tripped)
{
return(true);
}
if (!Monitor.TryEnter(_stateChangeLock))
{
return(_state == State.Tripped);
}
try
{
var snapshot = _metrics.GetSnapshot();
// If we haven't met the minimum number of operations needed to trip, don't trip.
if (snapshot.Total < _config.GetMinimumOperations(_key))
{
return(false);
}
// If we're within the error threshold, don't trip.
if (snapshot.ErrorPercentage < _config.GetThresholdPercentage(_key))
{
return(false);
}
_state = State.Tripped;
_lastTrippedTimestamp = _clock.GetMillisecondTimestamp();
_metricEvents.BreakerTripped(Name);
_log.Error($"Tripped Breaker={_key} Operations={snapshot.Total} ErrorPercentage={snapshot.ErrorPercentage} Wait={_config.GetTrippedDurationMillis(_key)}");
return(true);
}
finally
{
Monitor.Exit(_stateChangeLock);
}
}
internal FailurePercentageCircuitBreaker(GroupKey key, IClock clock, ICommandMetrics metrics, IStats stats, IMetricEvents metricEvents, FailurePercentageCircuitBreakerProperties properties, IConfigurableValue<long> gaugeIntervalMillisOverride = null)
{
_key = key;
_clock = clock;
_metrics = metrics;
if (stats == null)
{
throw new ArgumentNullException("stats");
}
if (metricEvents == null)
{
throw new ArgumentNullException("metricEvents");
}
_stats = stats;
_metricEvents = metricEvents;
Properties = properties;
_state = State.Fixed; // Start off assuming everything's fixed.
_lastTrippedTimestamp = 0; // 0 is fine since it'll be far less than the first compared value.
// Old gauge, will be phased out in v3.0 when IStats are removed.
_statsTimer = new GaugeTimer((source, args) =>
{
var snapshot = _metrics.GetSnapshot();
_stats.Gauge(StatsPrefix + " total", snapshot.Total >= properties.MinimumOperations.Value ? "Above" : "Below", snapshot.Total);
_stats.Gauge(StatsPrefix + " error", snapshot.ErrorPercentage >= properties.ThresholdPercentage.Value ? "Above" : "Below", snapshot.ErrorPercentage);
}, gaugeIntervalMillisOverride);
_metricsTimer = new GaugeTimer((source, args) =>
{
_metricEvents.BreakerConfigGauge(
Name,
Properties.MinimumOperations.Value,
Properties.ThresholdPercentage.Value,
Properties.TrippedDurationMillis.Value);
}, ConfigGaugeIntervalMillis);
}
internal FailurePercentageCircuitBreaker(GroupKey key, IClock clock, ICommandMetrics metrics, IStats stats, FailurePercentageCircuitBreakerProperties properties, IConfigurableValue <long> gaugeIntervalMillisOverride = null)
{
_key = key;
_clock = clock;
_metrics = metrics;
if (stats == null)
{
throw new ArgumentNullException("stats");
}
_stats = stats;
Properties = properties;
_state = State.Fixed; // Start off assuming everything's fixed.
_lastTrippedTimestamp = 0; // 0 is fine since it'll be far less than the first compared value.
_timer = new GaugeTimer((source, args) =>
{
var snapshot = _metrics.GetSnapshot();
_stats.Gauge(StatsPrefix + " total", snapshot.Total >= properties.MinimumOperations.Value ? "Above" : "Below", snapshot.Total);
_stats.Gauge(StatsPrefix + " error", snapshot.ErrorPercentage >= properties.ThresholdPercentage.Value ? "Above" : "Below", snapshot.ErrorPercentage);
}, gaugeIntervalMillisOverride);
}