This document discusses service oriented architecture using Thrift and Finagle. It introduces Apache Thrift as a framework for scalable cross-language services development with code generation. It also discusses Twitter's Finagle, an extensible asynchronous RPC system for the JVM. An example is provided of defining a ping service in Thrift IDL and implementing Scala clients and servers using Finagle and code generation with Scrooge. Python client code is also demonstrated.

1. SERVICE ORIENTED ARCHITECTURE
WITH THRIFT AND FINAGLE
Luka Zakrajšek
@bancek
First Scala meetup in Ljubljana
May 23, 2013

2. HI
I'm Luka. I work at Koofr,
Slovenian startup of the year

3. DISTRIBUTED SYSTEMS
redundancy
modularity
flexibility
needs to be simple

4. IT ENDS UP LIKE THIS

5. COMPONENTS MUST TALK
SOAP
XML-RPC
REST
Google Protocol Buffers
Apache Thrift

6. EXAMPLE

7. APACHE THRIFT
framework, for scalable cross-language
services development
code generation engine
C++, Java, Python, PHP, Ruby, Erlang,
Perl, Haskell, C#, Cocoa, JavaScript,
Node.js, Smalltalk, OCaml, Delphi, ...
Developed by Facebook,
opensourced in April 2007

8. APACHE THRIFT
Type system
Transport layer
Protocol layer
Processors
Server

9. TWITTER FINAGLE
extensible asynchronous (reactive)
RPC system for the JVM
uniform client and server APIs
for several protocols
high performance and concurrency
written in Scala
provides both Scala and Java idiomatic APIs

10. TWITTER FINAGLE
Asynchronous client/server for multiple protocols:
HTTP
Memcached
Redis
Protobuf
Thrift
MySQL
mDNS
...

11. THRIFT IDL
ping.thrift
namespace java com.example.ping
typedef string UUID
typedef i64 DateTime
struct Message {
1: required UUID id;
2: required string body;
3: optional DateTime sent;
}
service Ping {
Message ping(1:Message msg)
}

12. SCALA SERVER/CLIENT
Finagle for server/client
Scrooge for code generation
sbt-scrooge for SBT plugin
https://github.com/bancek/sbt-scrooge

13. SCALA SERVER
import com.twitter.util.Future
import com.example.ping._
class PingImpl extends Ping.FutureIface {
def ping(message: Message): Future[Message] = {
val returnMessage = message.copy(message="pong")
Future.value(returnMessage)
}
}

14. SCALA SERVER
import java.net.InetSocketAddress
import org.apache.thrift.protocol.TBinaryProtocol
import com.twitter.finagle.thrift.ThriftServerFramedCodec
import com.twitter.finagle.builder.ServerBuilder
val port = 1234
val processor = new PingImpl()
val service = new Ping.FinagledService(processor,
new TBinaryProtocol.Factory())
ServerBuilder()
.bindTo(new InetSocketAddress(port))
.codec(ThriftServerFramedCodec())
.name("ping")
.build(service)

15. SCALA CLIENT
import java.net.InetSocketAddress
import org.apache.thrift.protocol.TBinaryProtocol
import com.twitter.finagle.Service
import com.twitter.finagle.CodecFactory
import com.twitter.finagle.thrift.{ThriftClientFramedCodec,
ThriftClientRequest}
import com.twitter.finagle.builder.ClientBuilder
import com.example.ping._
val serviceCodec = ThriftClientFramedCodec()
val service: Service[ThriftClientRequest, Array[Byte]] =
ClientBuilder()
.hosts(new InetSocketAddress(host, port))
.codec(serviceCodec)
.build()

16. SCALA CLIENT
val message = Message(
id = "12341234-1234-1234-1234-123412341234",
body = "ping",
sent = 1369315198125
)
val pongFuture = client.ping(message)
pongFuture.onSuccess { pong =>
println(pong.message)
}

17. PYTHON CLIENT
Thrift code generator:
Thrift library dependency:
thrift --gen py:new_style,utf8strings ping.thrift
pip install thrift

18. PYTHON CLIENT
from thrift.transport import TSocket, TTransport
from thrift.protocol import TBinaryProtocol
from ping import Ping
from ping.ttypes import Message
transport = TSocket.TSocket('localhost', 1234)
transport = TTransport.TFramedTransport(transport)
protocol = TBinaryProtocol.TBinaryProtocol(transport)
transport.open()

19. PYTHON CLIENT
client = Ping.Client(protocol)
message = Message(
id='12341234-1234-1234-1234-123412341234',
body='ping',
sent=1369315198125
)
pong = client.ping(message)
print pong.message

20. QUESTIONS?