private static void ExecuteQueryImplementation(ClientRuntimeContext clientContext, int retryCount = 10, int delay = 500, string userAgent = null)
#endif
{
#if !ONPREMISES
await new SynchronizationContextRemover();
// Set the TLS preference. Needed on some server os's to work when Office 365 removes support for TLS 1.0
ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
#endif
var clientTag = string.Empty;
if (clientContext is PnPClientContext)
{
retryCount = (clientContext as PnPClientContext).RetryCount;
delay = (clientContext as PnPClientContext).Delay;
clientTag = (clientContext as PnPClientContext).ClientTag;
}
int retryAttempts = 0;
int backoffInterval = delay;
#if !ONPREMISES
int retryAfterInterval = 0;
bool retry = false;
ClientRequestWrapper wrapper = null;
#endif
if (retryCount <= 0)
{
throw new ArgumentException("Provide a retry count greater than zero.");
}
if (delay <= 0)
{
throw new ArgumentException("Provide a delay greater than zero.");
}
// Do while retry attempt is less than retry count
while (retryAttempts < retryCount)
{
try
{
clientContext.ClientTag = SetClientTag(clientTag);
// Make CSOM request more reliable by disabling the return value cache. Given we
// often clone context objects and the default value is
#if !ONPREMISES || SP2016 || SP2019
clientContext.DisableReturnValueCache = true;
#endif
// Add event handler to "insert" app decoration header to mark the PnP Sites Core library as a known application
EventHandler <WebRequestEventArgs> appDecorationHandler = AttachRequestUserAgent(userAgent);
clientContext.ExecutingWebRequest += appDecorationHandler;
// DO NOT CHANGE THIS TO EXECUTEQUERYRETRY
#if !ONPREMISES
if (!retry)
{
#if !NETSTANDARD2_0
await clientContext.ExecuteQueryAsync();
#else
clientContext.ExecuteQuery();
#endif
}
else
{
if (wrapper != null && wrapper.Value != null)
{
#if !NETSTANDARD2_0
await clientContext.RetryQueryAsync(wrapper.Value);
#else
clientContext.RetryQuery(wrapper.Value);
#endif
}
}
#else
clientContext.ExecuteQuery();
#endif
// Remove the app decoration event handler after the executequery
clientContext.ExecutingWebRequest -= appDecorationHandler;
return;
}
catch (WebException wex)
{
var response = wex.Response as HttpWebResponse;
// Check if request was throttled - http status code 429
// Check is request failed due to server unavailable - http status code 503
if (response != null && (response.StatusCode == (HttpStatusCode)429 || response.StatusCode == (HttpStatusCode)503))
{
Log.Warning(Constants.LOGGING_SOURCE, CoreResources.ClientContextExtensions_ExecuteQueryRetry, backoffInterval);
#if !ONPREMISES
wrapper = (ClientRequestWrapper)wex.Data["ClientRequest"];
retry = true;
// Determine the retry after value - use the retry-after header when available
// Retry-After seems to default to a fixed 120 seconds in most cases, let's revert to our
// previous logic
//string retryAfterHeader = response.GetResponseHeader("Retry-After");
//if (!string.IsNullOrEmpty(retryAfterHeader))
//{
// if (!Int32.TryParse(retryAfterHeader, out retryAfterInterval))
// {
// retryAfterInterval = backoffInterval;
// }
//}
//else
//{
retryAfterInterval = backoffInterval;
//}
//Add delay for retry, retry-after header is specified in seconds
await Task.Delay(retryAfterInterval);
#else
Thread.Sleep(backoffInterval);
#endif
//Add to retry count and increase delay.
retryAttempts++;
backoffInterval = backoffInterval * 2;
}
else
{
Log.Error(Constants.LOGGING_SOURCE, CoreResources.ClientContextExtensions_ExecuteQueryRetryException, wex.ToString());
throw;
}
}
}
throw new MaximumRetryAttemptedException($"Maximum retry attempts {retryCount}, has been reached.");
}