/// <summary>Parses an error message into a <see cref="CosmosError"/>.</summary>
/// <param name="message">The error message.</param>
/// <returns>An instance of <see cref="CosmosError"/>.</returns>
public static CosmosError ParseCosmosErrorMessage(string message)
{
var result = new CosmosError();
foreach (var el in message.Split(','))
{
var attr = el.Trim().Split('=');
if (attr.Count() != 2)
{
continue;
}
if (attr[0] == "Error")
{
result.ErrorCode = int.Parse(attr[1]);
}
if (attr[0] == "RetryAfterMs")
{
result.RetryAfterMs = int.Parse(attr[1]);
}
}
return(result);
}
/// <summary>Bulk upsert records.</summary>
/// <param name="observations">The set of observations to be loaded.</param>
/// <param name="maxRetries">Max number of retries that can be used if rate limited.</param>
/// <param name="carriedOverErrors">Accumulates errors over retries.</param>
/// <param name="performCheck">
/// If True, check if the record already exists and delete it. If False, the method attempts
/// a basic Insert operation.
/// </param>
/// <returns>True if success, False otherwise.</returns>
public bool UpsertMany(
IEnumerable <WeatherStationObservation> observations,
int maxRetries = 10,
IList <CosmosError> carriedOverErrors = null,
bool performCheck = true)
{
var collection = database.GetCollection <WeatherStationObservation>(config.CollectionName);
WeatherStationObservation[] observationsArr = observations.ToArray();
if (observationsArr.Count() == 0)
{
logger.LogInformation("No records to insert - nothing to do.");
return(true);
}
if (performCheck)
{
var checkId = observationsArr.First().Id;
var filter = Builders <WeatherStationObservation> .Filter.Eq("_id", checkId);
try
{
if (collection.CountDocuments(filter) > 0)
{
logger.LogInformation("Datastore not updated as data exists");
return(false);
}
}
catch (MongoCommandException e)
{
logger.LogInformation($"Couldn't perform check: {e.Message}");
if (maxRetries == 0)
{
logger.LogError($"Datastore update exception (no retries available): {e.Message}");
return(false);
}
var cosmosError = CosmosError.ParseCosmosErrorMessage(e.Message);
Task.Delay(cosmosError.RetryAfterMs);
UpsertMany(observations, maxRetries: maxRetries - 1, carriedOverErrors: carriedOverErrors, performCheck: true);
}
}
try
{
logger.LogInformation($"Records to be inserted: {observationsArr.Count()}");
collection.InsertMany(observationsArr);
logger.LogInformation("Datastore updated");
return(true);
}
catch (MongoCommandException e)
{
logger.LogError($"Unhandled exception: {e.Source} - {e.Message}");
return(false);
}
catch (MongoBulkWriteException <WeatherStationObservation> e)
{
if (maxRetries == 0)
{
logger.LogError($"Datastore update exception (no retries available): {e.Source} - {e.Message}");
return(false);
}
var errorList = CosmosError.ParseBulkWriteException(e);
var errorRecords = errorList.Select(we => observationsArr[we.Index]);
var unprocessedRecords = e.UnprocessedRequests
.Where(ur => ur.ModelType == WriteModelType.InsertOne)
.OfType <InsertOneModel <WeatherStationObservation> >()
.Select(ur => ur.Document);
var remainingObservations = unprocessedRecords.Union(errorRecords);
if (remainingObservations.Count() > 0)
{
int retryInterval = errorList.Max(rec => rec.RetryAfterMs) + rand.Next(1000, 5000);
logger.LogInformation($"Retrying {remainingObservations.Count()} records in {retryInterval}ms");
Task.Delay(retryInterval);
return(UpsertMany(
remainingObservations,
maxRetries: maxRetries - 1,
carriedOverErrors: carriedOverErrors,
performCheck: false));
}
return(false);
}
}
