title: Should I ever throw a retriable exception from my service
body: <p>My service is DService and I am fourth link in the chain of services i.e. the call flow is
  Online User -> AService -> BService -> CService -> DService -> EService.</p>
  
  <p>When I invoke EService from DService, it can throw retriable exception like HttpTimeoutException. I typically retry 2-3 three times and throw back an exception if it fails even after 2-3 retries.</p>
  
  <p>My question is, the exception which I am throwing to CService, should that be retriable or non-retriable? Please find below my evaluation of Pros &amp; Cons of both options</p>
  
  <p><strong>Cons of Throwing Retriable exception from DService</strong>
   - If DService throws a retriable exception, following the same convention CService also might retry DService 2-3 times and in each call of C-D, D will again try 2-3 times onto E service call. Likewise the calls ultimately to EService will increase exponentially as we go up the call chain. So If EService network was indeed down for long time, we are talking about long number of un-necessary calls. This can be mitigated by having timeouts for each call in the chain, still not sure if that's a enough mitigation against un-necessary number of calls.</p>
  
  <p><strong>Pros of Throwing Retriable exception from DService</strong>
   - CService will retry after sometime as in the subsequent retries we might get correct value (within the time limits)
   - Especially if the clients are some backend jobs, then they can exponentially retry for long time before giving up. Throwing Un-Retriable exception would weed out this option</p>
  
  <p>Please provide your views and suggestions on this</p>
  
  <p>Thanks,
  Harish</p>