SharePoint 429 Error - Throttling

Hi Robert.. yes sure please find below:

                for (var i = 0; i < 1000; i++)

                {

                    var lib = ctx.Web.Lists.GetByTitle(libraryName);

                    var items = lib.GetItems(new CamlQuery());

                    ctx.Load(items);

                    try

                    {

                        ctx.ExecuteQuery();

                    }

                    catch(System.Net.WebException wex)

                    {

                        var response = wex.Response as System.Net.HttpWebResponse;

                        if (response != null && (response.StatusCode == (System.Net.HttpStatusCode)429 || response.StatusCode == (System.Net.HttpStatusCode)503))

                        {

                            var retryAfter = Int32.Parse(response.Headers["Retry-After"].ToString());

                            Thread.Sleep(TimeSpan.FromSeconds(retryAfter));

                            ctx.ExecuteQuery();

                            try

                            {

                                var x = items.Count; // throws CollectionNotInitializedException

                            }

                            catch(Exception ex2)

                            {

                            }

                        }

                    }

                    Console.WriteLine($"{i}:{items.Count}");

                }

Some comments:

• I wrapping around the ExecuteQuery in a try/catch block and not the ctx.Load() because this suggested that should be enough: https://github.com/SharePoint/PnP/tree/dev/Samples/Core.Throttling
• My idea was to write an ExecuteQueryWithRetry code, similar to the one published by the PnP group but use your retry-after recommendation.  This way, all I’d need to change within my code is replacing all calls to ExecuteQuery with ExecuteQueryWithRetry.
• The problem is that the we get an error when accessing the items collection after a retry attempt.
• I guess a “solution” could be to encapsulate the “Load” in the try catch block as well but while this is easy to accomplish in the above code, in our real life scenario it gets much more tricky as there would be a lot of lines of code to modify.