Timeout error for AWS SNSClient Publish request - asp.net

Question

Here is the piece of code :
//Publishing the topic
snsClient.Publish(new PublishRequest
{
Subject = Constants.SNSTopicMessage,
Message = snsMessageObj.ToString(),
TopicArn = Settings.TopicArn
});
I am getting the below error :
The underlying connection was closed: A connection that was expected
to be kept alive was closed by the server.
And here is the screenshot of detailed error:
But not able to get an idea how to solve this. Any hint or link will helpful.

Answer 1

We had the exact same issue happen to us. We got this error about 40 times a day, which was less than 0.1% of the successful push notifications we sent out.
Our solution? Update the AWSSDK NuGet package from 1.5.30.1 to 2.3.52.0 (the latest v2 release for ease-of-upgrade). As soon as we updated, the errors stopped happening. I looked through lots of release notes and couldn't find anything specifically mentioning this issue. We have no idea why the update worked, but it did.
I hope this helps you and anyone else fix this issue.

Answer 2

This problem may occur when one or more of the following conditions are true:
• A network outage occurs.
• A proxy server blocks the HTTP request.
• A Domain Name System (DNS) problem occurs.
• A network authentication problem occurs.
[https://nilangshah.wordpress.com/2007/03/01/the-underlying-connection-was-closed-unable-to-connect-to-the-remote-server/]1

Answer 3

make sure your payloads size should not exceed more than 256 kb
make sure you had configured timeout property of the PutObjectRequest
Take a look sample aws sns request code (from https://stackoverflow.com/a/13016803/2318852)
// Create topic
string topicArn = client.CreateTopic(new CreateTopicRequest
{
Name = topicName
}).CreateTopicResult.TopicArn;
// Set display name to a friendly value
client.SetTopicAttributes(new SetTopicAttributesRequest
{
TopicArn = topicArn,
AttributeName = "DisplayName",
AttributeValue = "StackOverflow Sample Notifications"
});
// Subscribe an endpoint - in this case, an email address
client.Subscribe(new SubscribeRequest
{
TopicArn = topicArn,
Protocol = "email",
Endpoint = "sample#example.com"
});
// When using email, recipient must confirm subscription
Console.WriteLine("Please check your email and press enter when you are subscribed...");
Console.ReadLine();
// Publish message
client.Publish(new PublishRequest
{
Subject = "Test",
Message = "Testing testing 1 2 3",
TopicArn = topicArn
});
// Verify email receieved
Console.WriteLine("Please check your email and press enter when you receive the message...");
Console.ReadLine();
// Delete topic
client.DeleteTopic(new DeleteTopicRequest
{
TopicArn = topicArn
});