Azure Search RetryPolicy

Question

We are using azure search and need to implement a retry stratgey as well as storing the Ids of failed documents as described.

Is there any documentation/samples on how to implement a RetryPolicy strategy in Azure Search.

Thanks

Are you referring specifically to retrying when the Index API throws IndexBatchException? For all other cases, the .NET SDK already uses a default retry policy with exponential backoff. — Bruce Johnston
@brucejohnston Yes. As far as we can tell the default policy is for 500 errors but not if things like load issues cause a failure. — user2981411
Yes, you need to handle IndexBatchException explicitly. To clarify -- what do you mean by "storing" the IDs of failed documents? Do you mean persisting them? — Bruce Johnston

Martin Martin · Accepted Answer · 2017-06-11T09:20:50

This is what I used:

 private async Task<DocumentIndexResult> IndexWithExponentialBackoffAsync(IndexBatch<IndexModel> indexBatch)
 {
      return await Policy
           .Handle<IndexBatchException>()
           .WaitAndRetryAsync(5, retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)), (ex, span) =>
           {
                indexBatch = ((IndexBatchException)ex).FindFailedActionsToRetry(indexBatch, x => x.Id);
           })
           .ExecuteAsync(async () => await _searchClient.IndexAsync(indexBatch));
 }

It uses the Polly library to handle exponential backoff. In this case I use a model IndexModel that has a id field named Id. If you like to log or store the ids of the failed attempts you can do that in the WaitAndRetryAsync function like

((IndexBatchException)ex)ex.IndexingResults.Where(r => !r.Succeeded).Select(r => r.Key).<Do something here>

Azure Search RetryPolicy

2 Answers