service

Value Members

1. object ThriftMuxResponseClassifier

   

   ResponseClassifiers for use with finagle-thriftmux request/responses.

   ResponseClassifiers for use with finagle-thriftmux request/responses.

   Thrift (and ThriftMux) services are a bit unusual in that there is only a single com.twitter.finagle.Service from Array[Byte] to Array[Byte] for all the methods of an IDL's service.

   ThriftMux classifiers should be written in terms of the Scrooge generated request $Service.$Method.Args type and the method's response type. This is because there is support in Scrooge and ThriftMux.newService/newClient to deserialize the responses into the expected application types so that classifiers can be written in a normal way.

   Given an idl:

   exception NotFoundException { 1: string reason }
   exception RateLimitedException { 1: string reason }
   
   service SocialGraph {
     i32 follow(1: i64 follower, 2: i64 followee) throws (
       1: NotFoundException ex, 2: RateLimitedException ex
     )
   }
   

   One possible custom classifier would be:

   val classifier: ResponseClassifier = {
     case ReqRep(_, Throw(_: RateLimitedException)) => RetryableFailure
     case ReqRep(_, Throw(_: NotFoundException)) => NonRetryableFailure
     case ReqRep(_, Return(x: Int)) if x == 0 => NonRetryableFailure
     case ReqRep(SocialGraph.Follow.Args(a, b), _) if a <= 0 || b <= 0 => NonRetryableFailure
   }

   Often times, a good default classifier is ThriftMuxResponseClassifier.ThriftExceptionsAsFailures which treats any Thrift response that deserializes into an Exception as a non-retryable failure.