RetryHandler does not retry in case of 429 error

Question

Issue

When graph endpoint for adding tabs POST: /tabs gives throttling (429) error. When RetryHandler calls retryRequest it checks for isBuffered where it requires header Transfer-Encoding as Chunked, in order to send True and to set shouldRetry flag as True.
Issue Class : com.microsoft.graph.httpcore.RetryHandler (microsoft-graph SDK version 2.7.1)

Observations

Some times header "Transfer-Encoding = chunked" is missing in the response headers. Causing it to return False. As a result it sets shouldRetry flag as False and it never retry again.

Response Headers :
[
Cache-Control : private,
client-request-id : 5a064a73-9106-40ec-8dff-4069c5752de4,
Content-Length : 885,
Content-Type : application/json,
Date : Fri, 26 Feb 2021 14:03:23 GMT,
request-id : 64638ad8-1f98-49d1-9185-238341d4938e,
Retry-After : 60,
Strict-Transport-Security : max-age=31536000,
x-ms-ags-diagnostic :
{"ServerInfo": {"DataCenter":"SouthIndia","Slice":"SliceC","Ring":"3", "ScaleUnit":"001","RoleInstance":"AGSFE_IN_7" }}
]

Response Body :
{
"error": {
"code": "TooManyRequests",
"message": "Too many requests from Identifier:9155ce04-4eae-42ae-905e-ac219c282f72+786c9214-bb88-448d-9a43-3afeb1518b52+786c9214-bb88-448d-9a43-3afeb1518b52 under category:throttle.teams.ags.api_complex_level_10.tenant_normal.app_normal.operation_write_sustained. Please try again later.",
"innerError": {
"date": "2021-02-26T14:03:23",
"request-id": "64638ad8-1f98-49d1-9185-238341d4938e",
"client-request-id": "5a064a73-9106-40ec-8dff-4069c5752de4",
"status": 429,
"code": "429",
"message": "Too many requests from Identifier:9155ce04-4eae-42ae-905e-ac219c282f72+786c9214-bb88-448d-9a43-3afeb1518b52+786c9214-bb88-448d-9a43-3afeb1518b52 under category:throttle.teams.ags.api_complex_level_10.tenant_normal.app_normal.operation_write_sustained. Please try again later."
}
}
}

Steps to reproduce

1. Throttle the /tabs end point, by sending multiple tab addition requests for microsoft teams channels.
2. Use microsoft graph SDK for java to add tab in channel.

   Question

3. Why sometimes "Transfer-Encoding = chunked" header is missing?
4. Is there any workaround to this problem, so that I can use microsoft graph sdk ?

Answer 1

Hi AadityaRane-1988, We have tested the retry handler code using parallel loop by taking threshold limit = 200, didn't face any issue while creating the tab in this scenario. Could you please try with below code.

int i, n = 200;  
Parallel.For(0, n, i =>  
{  
var teamsTab = new TeamsTab  
{  
DisplayName = "My Tab" + i,  
Configuration = new TeamsTabConfiguration  
{  
EntityId = "2DCA2E6C7A10415CAF6B8AB66121435",  
ContentUrl = _configuration["BaseUri"] + "/TestTab" + i,  
WebsiteUrl = _configuration["BaseUri"] + "/TestTab" + i  
},  
AdditionalData = new Dictionary<string, object>()  
{  
{ "******@odata.bind", "https://graph.microsoft.com/v1.0/appCatalogs/teamsApps/" + teamsAppId }  
}  
};  
  
 var result = graphClient.Teams[teamId].Channels[channelId].Tabs  
.Request()  
.AddAsync(teamsTab);  
});  

Answer 2

The issue was got fixed in msgraph-sdk-java-core 1.0.9

https://github.com/microsoftgraph/msgraph-sdk-java-core/issues/160