Retry Pattern https://msdn.microsoft.com/en-us/library/dn589788.aspx
https://msdn.microsoft.com/en-us/library/dn600223.aspx
http://www.servicedesignpatterns.com/WebServiceInfrastructures/IdempotentRetry
Idempotency Patterns
http://blog.jonathanoliver.com/idempotency-patterns/