private async Task DetectChanges()
{
// TODO -- need to put some retry & exception handling here.
try
{
_current = await _detector.Detect(_token);
if (_current.CurrentMark > 0)
{
_tracker.MarkHighWater(_current.CurrentMark);
}
}
catch (Exception e)
{
_logger.LogError(e, "Failed while making the initial determination of the high water mark");
}
await Task.Delay(_settings.FastPollingTime, _token);
while (!_token.IsCancellationRequested)
{
HighWaterStatistics statistics = null;
try
{
statistics = await _detector.Detect(_token);
}
catch (Exception e)
{
_logger.LogError(e, "Failed while trying to detect high water statistics");
await Task.Delay(_settings.SlowPollingTime, _token);
continue;
}
var status = statistics.InterpretStatus(_current);
switch (status)
{
case HighWaterStatus.Changed:
await markProgress(statistics, _settings.FastPollingTime);
break;
case HighWaterStatus.CaughtUp:
await markProgress(statistics, _settings.SlowPollingTime);
break;
case HighWaterStatus.Stale:
var safeHarborTime = _current.Timestamp.Add(_settings.StaleSequenceThreshold);
var delayTime = safeHarborTime.Subtract(statistics.Timestamp);
if (delayTime.TotalSeconds > 0)
{
await Task.Delay(delayTime, _token);
}
statistics = await _detector.DetectInSafeZone(safeHarborTime, _token);
await markProgress(statistics, _settings.FastPollingTime);
break;
}
}
_logger.LogInformation("HighWaterAgent has detected a cancellation and has stopped polling");
}
private async Task DetectChanges()
{
if (!IsRunning)
{
return;
}
try
{
_current = await _detector.Detect(_token).ConfigureAwait(false);
if (_current.CurrentMark > 0)
{
_tracker.MarkHighWater(_current.CurrentMark);
}
}
catch (Exception e)
{
_logger.LogError(e, "Failed while making the initial determination of the high water mark");
}
await Task.Delay(_settings.FastPollingTime, _token).ConfigureAwait(false);
while (!_token.IsCancellationRequested)
{
if (!IsRunning)
{
break;
}
HighWaterStatistics statistics = null;
try
{
statistics = await _detector.Detect(_token).ConfigureAwait(false);
}
catch (Exception e)
{
_logger.LogError(e, "Failed while trying to detect high water statistics");
await Task.Delay(_settings.SlowPollingTime, _token).ConfigureAwait(false);
continue;
}
var status = statistics.InterpretStatus(_current);
switch (status)
{
case HighWaterStatus.Changed:
await markProgress(statistics, _settings.FastPollingTime).ConfigureAwait(false);
break;
case HighWaterStatus.CaughtUp:
await markProgress(statistics, _settings.SlowPollingTime).ConfigureAwait(false);
break;
case HighWaterStatus.Stale:
_logger.LogInformation("High Water agent is stale at {CurrentMark}", statistics.CurrentMark);
// This gives the high water detection a chance to allow the gaps to fill in
// before skipping to the safe harbor time
var safeHarborTime = _current.Timestamp.Add(_settings.StaleSequenceThreshold);
if (safeHarborTime > statistics.Timestamp)
{
await Task.Delay(_settings.SlowPollingTime, _token).ConfigureAwait(false);
continue;
}
_logger.LogInformation("High Water agent is stale after threshold of {DelayInSeconds} seconds, skipping gap to events marked after {SafeHarborTime}", _settings.StaleSequenceThreshold.TotalSeconds, safeHarborTime);
statistics = await _detector.DetectInSafeZone(_token).ConfigureAwait(false);
await markProgress(statistics, _settings.FastPollingTime).ConfigureAwait(false);
break;
}
}
_logger.LogInformation("HighWaterAgent has detected a cancellation and has stopped polling");
}