service

Value Members

1. object ThriftReqRepServicePerEndpoint

   

   Construct Service[scrooge.Request[method.Args],scrooge.Response[method.SuccessType]] interface for a ThriftMethod.

   Construct Service[scrooge.Request[method.Args],scrooge.Response[method.SuccessType]] interface for a ThriftMethod.

   There are two ways to use a Scrooge-generated Thrift Service with Finagle:

   1. Using a Service interface, i.e. a collection of Finagle Services, e.g., ReqRepServicePerEndpoint.

   2. Using a method interface, i.e. a collection of methods returning Futures, e.g, MethodPerEndpoint.

   Example: for a Thrift service IDL:

   service Logger {
     string log(1: string message, 2: i32 logLevel);
     i32 getLogSize();
   }

   the Service interface, or ReqRepServicePerEndpoint, is

   trait LoggerServiceIface {
     val log: com.twitter.finagle.Service[scrooge.Request[Logger.Log.Args], scrooge.Response[Logger.Log.SuccessType]]
     val getLogSize: com.twitter.finagle.Service[[scrooge.Request[Logger.GetLogSize.Args], scrooge.Response[Logger.GetLogSize.SuccessType]]
   }

   and the method interface, or MethodPerEndpoint, is

   trait Logger[Future] {
     def log(message: String, logLevel: Int): Future[String]
     def getLogSize(): Future[Int]
   }

   ReqRepServicePerEndpoints can be modified and composed with Finagle Filters.

2. object ThriftResponseClassifier

   

   ResponseClassifiers for use with finagle-thrift request/responses.

   ResponseClassifiers for use with finagle-thrift request/responses.

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

   Thrift 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 Thrift.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 // avoid this style!
   }

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

   See also

   The user guide for more information on Response Classification of Thrift and ThriftMux Clients and Servers.

3. object ThriftServicePerEndpoint

   

   Construct Service interface for a Thrift method.

   Construct Service interface for a Thrift method.

   There are two ways to use a Scrooge-generated Thrift Service with Finagle:

   1. Using a Service interface, i.e. a collection of Finagle Services.

   2. Using a method interface, i.e. a collection of methods returning Futures.

   Example: for a Thrift service IDL:

   service Logger {
     string log(1: string message, 2: i32 logLevel);
     i32 getLogSize();
   }

   the Service interface, or ServicePerEndpoint, is

   trait LoggerServicePerEndpoint {
     val log: com.twitter.finagle.Service[Logger.Log.Args, Logger.Log.SuccessType]
     val getLogSize: com.twitter.finagle.Service[Logger.GetLogSize.Args, Logger.GetLogSize.SuccessType]
   }

   and the method interface, or MethodPerEndpoint, is

   trait Logger[Future] {
     def log(message: String, logLevel: Int): Future[String]
     def getLogSize(): Future[Int]
   }

   Service interfaces can be modified and composed with Finagle Filters.