1、25.10.2007,1,Integrating OTP with Enterprise Service Bus,OAS (OTP Application Server),Leslaw Lopacki Telenor IS Nordic, Norway ,25.10.2007,,2,Background what is SOA?,What is Service Oriented Architecture?: Is a collection of services which communicate with each other Uses loosely-coupled relationshi
2、ps between producer and consumer Has no direct relationship with software, programming, or technology Services can be accessed without knowledge of their underlying platform implementation ORB/CORBA is probably a first SOA implementation Services are ”usually” defined using WSDL/XSD Messages are ”us
3、ually” SOAP/XML based but not only,ESB,25.10.2007,,3,What is OAS and OESB?,OAS OTP based Application Server: Provides a simple framework for building Erlang based ”Beans” deployed as Erlang processes 2 types supported: Dynamic workers started dynamically on demand Static Workers registered processes
4、 (Singletons) Technically it isnt a JEE App Server it simply does not support all JEE specs but thats not an issue here OESB Connects ESB and OAS: uses SOAP 1.1 ErlSoap 0.4.3,25.10.2007,,4,CoMet/Metro/COS at Telenor,How this idea was born?: Metro and COS are integration platforms with ca 50 systems
5、(running at Telenor): 2 different Application Servers: IBM WebSphere and BEA WebLogic Close integration of JEE and .NET applications CoMet is a new integration platform which integrates Metro, COS: Uses SOA Enterprise Service Bus from BEA Very limited/no use of Erlang: Only isolated systems e.g. Jab
6、ber server We could consider using OTP/Erlang in some installations if it was easier to integrate: e.g. using SOAP/XSD/WSDL,25.10.2007,,5,Motivation for OESB,Erlang integrates poorly with large enterprise architectures But thanks to SOA the systems can be more heterogeneous: i.e. appearance of SOA m
7、akes it easier to integrate ”small languages” (Erlang ) with the ”big ones” (JEE, .NET, ) OTP is far more cost-efficient than any existing JEE Application Server, e.g.: Built in efficient look up of resources reduces “glue code” Built in database: mnesia Offensive approach: simpler “exception handli
8、ng”, less code needed to get things done SOA and: OO does not integrate so well FP seams to be a perfect matchConclusion: SOA brings an opportunity to introduce OTP in existing installations,25.10.2007,,6,OTPs weaknesses from SOA point of view,Good built in SOAP libraries are essential: ErlSoap is r
9、ather limited i.e. it does not support WSDL Yaws contains some WSDL support (not evaluated here) Lack of infrastructure to quickly deploy applications application servers Not optimal for “frontend” systems: GUI design support is poor ! Poor support for Web Services and Web technologies,25.10.2007,,7
10、,OESB Architecture,Web Logic Application Server (WLS),ESB - Aqua Logic Service Bus (ALSB),OTP Application Server (OAS),SOAP,SOAP,25.10.2007,,8,Demo system,Demo of cinema booking system Exemplifies strong sides: of an App Server: like Web GUI and integration with legacy JEE systems of OTP/Erlang: lik
11、e high transactional throughput, low latency reliable data storage, FSM support, reliability and scalability,25.10.2007,,9,Web Logic App. Server: Demo Design,WLS,BookingApplication (JSP),BookingBean (JEE State-Less Session Bean),ALSB,25.10.2007,,10,OTP Application Server: Demo Design,OAS,ALSB,bookin
12、g_dwk,booking_dwk,booking_dwk,booking_dwk,booking_dwk,cinema_wk,cinema_wk,oas_engine,oesb (erlsoap),25.10.2007,,11,idle,selected,rebook_seat/rebook,paid,pay_seat_ok/book,rebooking,cancel_seat/release,no_pay/release,select_seat_ok/answer_ok,timeout/deselect,FSM for booking_agent,selecting,select_seat
13、/select,select_seat_nok/answer_nok,rebook_seat_nok/answer_nok,rebook_seat_ok/answer_ok,25.10.2007,,12,Demo,Lets look at a few glimpses of an implementation example,25.10.2007,,13,OESB Enhancements (Future),Take full advantage of OTP Make it scalable: Load balancing support Make it more reliable Better redundancy/replication support,
