Feb 12 2018 03:09 AM
Feb 12 2018 03:09 AM
We have a custom code application which hits SharePoint with multiple ExecuteQueries. This has been running fine for 6 months. From last week, we began receiving a lot of 429 Errors.
We made sure that that there is a delay of up to 3 secs between each ExecuteQuery and also decorated the HTTP calls as Microsoft suggest in (https://docs.microsoft.com/en-us/sharepoint/dev/general-development/how-to-avoid-getting-throttled-o...). Also multiple users are being used so that not always the same user is used when hitting SharePoint.
Has anyone encountered this? Does anyone know the actual values of throttling in SharePoint or what triggers it?
Feb 12 2018 03:49 AM
Instead of 3 seconds delay between each query, you can execute one after the other. If you encounter 429 error, just inspect the response header for 'retry-after' entry. This retry-after field will contain the number of seconds you need to wait until you make your next query.
Feb 12 2018 03:57 AM
Feb 12 2018 04:49 AM
We already have tried this but unfortunately when there is a 429 error, and the ExecuteQuery retries, the returned information will contain missing fields. For example the File name of the item is returned as empty.
So unfortunately this was leading us to other issues and that's why we created a delay of 3 secs between each ExecuteQuery.
Feb 12 2018 04:59 AM
ExecuteQuery retries, the returned information will contain missing fields - This should not happen!. Can you share your retry code?
Feb 12 2018 11:39 AM
Feb 12 2018 07:14 PM
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());
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());
var x = items.Count; // throws CollectionNotInitializedException
Feb 12 2018 09:53 PM
Feb 13 2018 06:03 PM
We just got hit with this today as well. In my case i simply connected via powershell to enable a cdn and got a 429 back from a single request. I've seen a few posts on this. feels like something changed recently
Feb 20 2018 09:55 AM
Feb 21 2018 01:48 AM
At least you got that reply :)
We have been in contact with Microsoft Support for quiet a while now and we did not get any specific reply like yours :\
However it does not make sense that you are being throttled during business hours for normal use. We have been using this scenario for months (after multiple migrations to SharePoint) and we never had this issue. So I find it very strange that all of a sudden we began to experience this throttling issue.
One item which Microsoft told us was that it could be the case that other tenants could be effecting the overall SharePoint experience, hence effecting other tenants. But again it does not make from a customer perspective.
Feb 21 2018 02:56 AM
I've been battling this for a few weeks now as well and have a support ticket open with Microsoft. Decorating the requests with a UserAgent has helped as per this guidance
It seems you can make up and Company name | Product Name | Version and although the article say to "register" the app, I've not been able to find anyone in Microsoft which whom to give these values to. It seems the mere presence of the values in the right format makes a difference but won't prevent the 429 responses from occurring. Our testing has concluded that the 429 throttling responses (without decorating the requests) happens during business hours at the data centre (peak times) and is heavily influences by other traffic happening in the data centre at the time and not purely how many and how frequent the calls from your code is. e.g. I can get a 429 making a single call (no other calls for hours before it), yet I can make > 5000 calls to SharePoint in a couple of minutes and not get a single throttling error.
As an aside I've identified an issue using the Graph API to access SharePoint items where it will always return a 429 throttling response when it's actually the query hitting a SharePoint threshold (large list) limit so you will want to check this isn't the case if you are seeing this issue as that one is easier to identify and avoid!
Feb 25 2018 07:46 AM
Sharegate has released a new version which should get a higher priority from Microsoft which than should decrease the number of 429. We did not try this version yet because we finished our migration.
The 429 throttling errors are to protect the tenant so they might occur in different situations in different tenants. Our was situated in the UK and we were throttled suddenly in Feb-2018. Before we did not have any 429 issues and we converted 6Tb before. When moving off hours we were able to run Sharegate again without many 429 errors. Microsoft has a SLA on availability NOT on performance that is why they will do anything to protect their office365 tenants.
Feb 25 2018 02:09 PM
The timing of 429 errors starting to appear was early Feb 2018 for me as well. Other threads and people I've had conversations with share this timeline as well. It seems something changed in either the way throttling happens or the thresholds were tightened around this time - still trying to get some official information from Microsoft.
Feb 26 2018 12:32 AM
Our exact same conclusion.
Symptoms all started in Feb 2018 and we're also trying to obtain more information from Microsoft, but so far we keep being redirected on 'how to avoid 429 errors' rather than what led to this situation. We have worked with no issues for the past 6 months, including migration.
As you mentioned earlier, we also came across instances where a single call triggers error 429 and other times with heavy load and this does not occur.
Feb 26 2018 12:37 AM
Further to this, the 2 main issues are;
- the disruption such unannounced changes create in production environments
- the lack of information on what changed in Feb 2018
Mar 12 2018 02:25 AM
Thanks everyone for sharing your finding. We would really appreciate if you could report these issues using our official sp-dev-docs issue list at https://github.com/SharePoint/sp-dev-docs/issues. This issue list is automatically synced with our engineering task list so that we can ensure that your issue does not get hidden or ignored.
Would ask following from each of you, so that we can start solving these one-by-one.
- Which tenant has the issue?
- When did the issue happen, so that we can check right log entries?
- What was your code performing when this happened?
- Did you use a user-agent string as instructed in https://docs.microsoft.com/en-us/sharepoint/dev/general-development/how-to-avoid-getting-throttled-o...?
There should NOT be any world-wide change on this capability which should be this widely impacting, but apparently, issues are seen in multiple tenants, so we need actual facts and technical details to analyze what has happened. We can't really investigate the underlying issue without tenant and timing details.
Thanks for your input advance. Even if your issue seems to be identified as the previously reported issue, would suggest submitting a new issue so that we truly understand how widely these throttling issues are being encountered.
Also in the future - Please use the https://github.com/SharePoint/sp-dev-docs/issues issue list for this kind of issues. This list exists for you to be able to directly report issues to engineering. Thx.
Mar 13 2018 01:06 AM
Thanks @Vesa Juvonen for you reply. We have opened a new issue in the list provided and answering all your questions there.
These issues were occurring mainly in February. Our target here is to identify what caused these errors and why. We are planning to move more services to SharePoint and such issues will hold us back until we fully migrate our services, since it will effect usability of custom built applications for our Business to run on SharePoint.
Mar 14 2018 02:49 AM
Dear @Vesa Juvonen
As to support, we tried to open this through the normal O365 channels and through our distributor. The case was # 30126-7340755.
Unfortunately we were never directed to the site you mentioned and if you have access to this case, you may see that most of our questions in relation to throttling were not answered. The standard reply was;
"As discussed earlier we as a frontline support will not be able to provide you any further support on this scenario. Also according to the scope of the service request this is out of support boundary and we are proceeding with the archival of this service request 30126-7340755"
We were being directed to how to avoid throttling with each support engineer, as against replying to our queries as to how and why the throttling occurred and started out of nowhere.
I believe Justin has followed your advise and replied accordingly.
Many thanks for following this up.
Apr 24 2018 03:34 AM
we're currently experiencing the same situation in our tenants and our customer's tenants. Since 2/3 weeks ago, the 429 errors are suddenly increasing without any configuration changes or updates.
Also using incremental backoff retry and User Agent.
We created an ASPX page that can be uploaded to any Azure web app and simply performs a CSOM query every 5 sec. against SharePoint online. We can see how this operation returns 429 a significant amount of times in these tenants. In case it's useful for someone, it's attached to this comment.
As we didn't get any official reply from MS yet, did you guys manage to get an explanation or a satisfactory resolution to your cases? Did the errors just go or were there any actions involved?
We feel we're quite in the dark here...