public async Task ReloadStationsAndUpdateTsmAsync()
{
Logger.TraceLine("Loading stations.");
while (true)
{
bool noaaThrottlingDetected = false;
try
{
await _stationsProcessor.ReloadStationsAsync();
}
catch (Exception e)
{
noaaThrottlingDetected |= Retry.UnwrapAggregateException <NoaaThrottlingDetected>(e) != null;
if (!noaaThrottlingDetected)
{
throw;
}
}
if (noaaThrottlingDetected)
{
Logger.TraceLine($"Detected NOAA throttling, waiting until {DateTime.Now + DelayOnNoaaThrottling}");
await Task.Delay(DelayOnNoaaThrottling);
}
else
{
break;
}
}
Logger.TraceLine($"Loaded {_stationsProcessor.Stations.Length} stations.");
var stationObservationProcessors = new Dictionary <string, StationObservationsProcessor>(_stationsProcessor.Stations.Length);
foreach (Station station in _stationsProcessor.Stations)
{
stationObservationProcessors.Add(
station.Id,
_stationObservationProcessors.ContainsKey(station.Id)
? _stationObservationProcessors[station.Id] :
new StationObservationsProcessor(station.ShortId, _noaaClient, _eventHubClient, _stationObservationsCheckpointing));
}
_stationObservationProcessors = stationObservationProcessors;
Logger.TraceLine("Updating TSM.");
if (await _stationsProcessor.UpdateTsmAsync())
{
Logger.TraceLine($"Updated TSM for {_stationsProcessor.Stations.Length} stations.");
}
else
{
Logger.TraceLine("TSM update skipped.");
}
}
private async Task <TResult> MakeNoaaApiCall <TResult>(
string requestUriString,
Func <TextReader, TResult> consumeResponseTextReader)
{
try
{
return(await HttpUtils.MakeHttpCallAsync(requestUriString, consumeResponseTextReader, pretendBrowser : true));
}
catch (Exception e)
{
WebException webException = Retry.UnwrapAggregateException <WebException>(e);
if (webException != null)
{
HttpWebResponse response = (HttpWebResponse)webException.Response;
if (response != null && response.StatusCode == HttpStatusCode.Forbidden)
{
throw new NoaaThrottlingDetected();
}
}
throw;
}
}
public static async Task <bool> DeleteTableRowIfExistsAsync(CloudTable table, string partitionKey, string rowKey)
{
TableOperation deleteOperation = TableOperation.Delete(new TableEntity(partitionKey, rowKey)
{
ETag = "*"
});
try
{
await table.ExecuteAsync(deleteOperation);
return(true);
}
catch (Exception e)
{
StorageException storageException = Retry.UnwrapAggregateException <StorageException>(e);
if (storageException == null || storageException.RequestInformation.HttpStatusCode != 404)
{
throw;
}
return(false);
}
}
public async Task Run()
{
DateTime?updateStationsTimestamp = null;
var tasks = new List <Task>(HttpUtils.DefaultConnectionLimit);
int passCount = 1;
while (true)
{
// Make a pass thru all stations.
Logger.TraceLine($"PASS {passCount} START");
Stopwatch stopwatch = Stopwatch.StartNew();
if (updateStationsTimestamp == null || DateTime.Now - updateStationsTimestamp > UpdateStationsInterval)
{
await ReloadStationsAndUpdateTsmAsync();
updateStationsTimestamp = DateTime.Now;
}
List <StationObservationsProcessor> stationObservationsProcessors = _stationObservationProcessors.Values.ToList();
bool noaaThrottlingDetected = false;
while (stationObservationsProcessors.Count > 0 || tasks.Count > 0)
{
while (stationObservationsProcessors.Count > 0 &&
tasks.Count < System.Net.ServicePointManager.DefaultConnectionLimit)
{
StationObservationsProcessor stationObservationsProcessor = stationObservationsProcessors[0];
tasks.Add(stationObservationsProcessor.ProsessStationObservationsAsync());
stationObservationsProcessors.RemoveAt(0);
}
Task completedTask = await Task.WhenAny(tasks);
tasks.Remove(completedTask);
try
{
await completedTask;
}
catch (Exception e)
{
noaaThrottlingDetected |= Retry.UnwrapAggregateException <NoaaThrottlingDetected>(e) != null;
if (noaaThrottlingDetected)
{
// Skip remaining work on this pass.
stationObservationsProcessors.Clear();
}
else
{
throw;
}
}
}
TimeSpan delay;
if (noaaThrottlingDetected)
{
Logger.TraceLine($"PASS {passCount} CANCELLED: Detected NOAA throttling, waiting until {DateTime.Now + DelayOnNoaaThrottling}");
delay = DelayOnNoaaThrottling;
}
else
{
Logger.TraceLine($"PASS {passCount} DONE: Elapsed {stopwatch.Elapsed}");
delay = (_stationObservationProcessors.Values.Min(sop => sop.GoodNextTimeToProcess) - DateTime.Now) + TimeSpan.FromMinutes(1);
delay = NormalPassDelay > delay ? NormalPassDelay : delay;
}
++passCount;
Logger.Flush();
await Task.Delay(delay);
}
}
