Microsoft Graph API - 获取 Sharepoint 文档库中的项目列表时超时 (C# ASP DotNet)

Question

I'm using Microsoft Graph API to get a list of documents in a Sharepoint Document Library. Code was fine for 6 months. Last Friday my code broke.

There are about 700 documents in the library, and in the past the request would complete after 5-6 seconds. As of last Friday (23/09/2022) it started timing out after (~120 seconds). If I limit it to 200 rows, it works after 12 seconds, but I need all 700, If there is a way to do paging that could work. then I could make my own method. Also if I could increase the timeout it might work - I have tried modifying both the GraphClient.HttpProvider.OverallTimeout and the request,WithMaxRetry to 900 seconds. but it still times out after around 122 seconds.

Here is the relevant part of my code (rowLimit is an int set to 5000):

List<QueryOption> queryOptions = new List<QueryOption>()
            {
                new QueryOption("Top", $"{rowLimit}"),
                new QueryOption ("Prefer","allowthrottleablequeries")
            };

IDriveItemChildrenCollectionPage result = await GraphClient.Sites[siteID].Drives[documentLibraryID].Root.Children
                    .Request(queryOptions)
                    .Expand("listItem")
                    .WithMaxRetry(1) //set 1 max retry and set timeout
                    .WithMaxRetry(TimeSpan.FromSeconds(900)
                    .GetAsync();

After ~122 seconds I receive the following exception: Code: tooManyRetries Message: More than 1 retries encountered while sending the request.

As mentioned, I can get it to work if I limit the number of rows - 200 rows return in around 12 seconds, 400 rows return in around 24 seconds. The strange thing is it was fine last week, so perhaps Microsoft changed something?

Answer 1

I managed to work around my issue by using pagination:

List<DriveItem> allItems = new();

var result = await GraphClient.Sites[siteID].Drives[documentLibraryID].Root.Children
                .Request()
                .Expand("listItem")
                .Top(100)
                .GetAsync();

            var pageIterator = PageIterator<DriveItem>
                .CreatePageIterator(
                    GraphClient,
                    result,
                    (item) =>
                    {
                        allItems.Add(item);
                        return true;
                    });

            await pageIterator.IterateAsync();

This way I get the results 100 at a time, which was within the timeout threshold. They are then all added to a List (allItems) so I didn't need to change the rest of my code.