On Using Ice Middleware in the IARnet Framework

1. On Using Ice Middlewarein the IARnet Framework Oleg Sukhoroslov Institute for Systems Analysis, RAS, Moscow Distributed Computing Systems Laboratory

2. What is missing in IARnet • Securityencryption, data integrity, authentication, authorization, session management … • Full-featured interface definition languageuser-defined complex types, exceptions … • Advanced configuration and deploymentfile-based service configuration, grid site model

3. IARnet2 • Built-in security • Scalable site model, flexible configuration • Avoids unnecessary complexity • IARnet1: Pluggable transports: CORBA, Web Services, Ice • IARnet2: Based on a single middleware technology, Ice

4. Ice (Internet Communications Engine) • Object middleware technology developed by ZeroC, Inc • Supports programming of servers and clients in C++, Java, C#, Visual Basic, Python, PHP (client only), Ruby (client only) • Support for various operating systems and embedded devices • Available under GPL • Slice - full-featured interface definition language • Ice core - communication library, highly efficient protocol, compression, TCP/UDP, thread pool for multi-threaded servers • IceSSL - dynamic SSL transport plug-in for the Ice core • IceBox - container for Ice services that are dynamically loaded as a DLL, shared library, or Java class • IceGrid - sophisticated server configuration, deployment and activation tool for management of complex server infrastructure • Glacier - firewall solution for Ice • Messaging service, persistence solution, patching service …

5. Web Services vs. Ice

6. WSDL vs. Slice <?xml version="1.0"?> <definitions name="StockQuote" targetNamespace="http://example.com/stockquote.wsdl" xmlns:tns="http://example.com/stockquote.wsdl" xmlns:xsd1="http://example.com/stockquote.xsd" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns="http://schemas.xmlsoap.org/wsdl/"> <types> <schema targetNamespace=“http://example.com/stockquote.xsd” xmlns="http://www.w3.org/2000/10/XMLSchema"> <element name="TradePriceRequest"> <complexType> <all> <element name="tickerSymbol" type="string"/> </all> </complexType> </element> <element name="TradePrice"> <complexType> <all> <element name="price" type="float"/> </all> </complexType> </element> </schema> </types> <message name="GetLastTradePriceInput"> <part name="body" element="xsd1:TradePriceRequest"/> </message> <message name="GetLastTradePriceOutput"> <part name="body" element="xsd1:TradePrice"/> </message> <portType name="StockQuotePortType"> <operation name="GetLastTradePrice"> <input message="tns:GetLastTradePriceInput"/> <output message="tns:GetLastTradePriceOutput"/> </operation> </portType> <binding name="StockQuoteSoapBinding“type="tns:StockQuotePortType"> <soap:binding style="document“transport="http://schemas.xmlsoap.org/soap/http"/> <operation name="GetLastTradePrice"> <soap:operationsoapAction="http://example.com/GetLastTradePrice"/> <input> <soap:body use="literal"/> </input> <output> <soap:body use="literal"/> </output> </operation> </binding> <service name="StockQuoteService"> <documentation>My first service</documentation> <port name="StockQuotePort" binding="tns:StockQuoteBinding"> <soap:address location="http://example.com/stockquote"/> </port> </service> </definitions> // My first service interface StockQuoteService { float GetLastTradePrice(string tickerSymbol); };

7. Basic Concepts • IARnet2 Service – an Ice object, which provides access to some scientific tool or application • Described by means of Slice language • Implemented as an Ice servant • IARnet2 Client – an Ice application, which accesses IARnet2 services on behalf of a user or another service

8. IARnet2 Site • A collection of services, which are installed and managed • by some organization or person. • Provides a unified interface for accessing service • Can scale from a single computer to server pool

9. Site Interface interface Site { Session* createSession(string userId, string password) throws PermissionDeniedException, CannotCreateSessionException; Session* createSessionFromSecureConnection() throws PermissionDeniedException, CannotCreateSessionException; idempotent long getSessionTimeout(); };

10. Session Interface interface Session { Object* getService(string serviceId) throws ServiceNotFoundException, PermissionDeniedException; idempotent void keepAlive(); void destroy(); };

11. Site Architecture

12. Site Deployment Modes

13. Simple VO Setup

14. Current Implementation (Java) • Site implementation • Based on IceBox for Java • Two permissions verifiers: MD5PermissionsVerifier, SimpleSSLPermissionsVerifier • Web interface (embedded Jetty server) • Distributed site mode supports the use of IceGrid • Client API • Session creation • Keeping sessions alive • Obtaining service proxies • Backwards compatible with IARnet

15. Service Programming Model • Define service interface in Slice (or start with an existing definition) • Compile Slice to Java code • Implement the service as a Java class • Deploy the service • Edit server configuration file (2 lines minimum) • Drop jar file into the server /lib directory

16. Client Programming Model // create client session ClientSession session = new ClientSessionImpl(communicator()); // create service reference ServiceReference ref = ServiceReferenceFactory.create( "StatelessCalculator@DCS.ISA.RU: ssl -h dcs.isa.ru -p 7070", communicator()); // get service StatelessCalculatorPrx calc = session.getService(ref,StatelessCalculatorPrx.class); // invoke service double result = calc.add(1, 2);

17. Conclusion • The use of Ice made it possible to provide with a minimal effort all the needed functionality and ensure high performance • The programming model was improved, while keeping it as simple as possible • IARnet2 site supports grid site model and can scale from a single desktop to server pool • Working on top of existing Grid infrastructure: • Leverage existing PKI infrastructure and VO membership services • Building IARnet2 services, which use Grid infrastructure for submitting batch jobs and data movement

18. Thank you! For more information: Oleg Sukhoroslov, os@isa.ru

19. Basic IARnet2 Components