On Using Ice Middleware in the IARnet Framework Oleg Sukhoroslov Institute for Systems Analysis, RAS, Moscow Distributed Computing Systems Laboratory

What is missing in IARnet Security encryption, data integrity, authentication, authorization, session management … Full-featured interface definition language user-defined complex types, exceptions … Advanced configuration and deployment file-based service configuration, grid site model

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

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 …

Web Services vs. Ice Web ServicesIce Object-oriented development - (WSRF?)+ Interface definition language WSDL is too complex to write manually Slice is easy to write and read Protocol performance SOAP is slow, wasteful of bandwidth, puts load on CPU Binary protocol, ~100x better latency and throughput MaturityLarge number of WS-* specs, some are still “work in progress” Stable, well-documented API and protocol Available implementations Many, but each vendor uses its own proprietary API and tools. Lack of WSRF implementations. Single. Has well-documented language mappings, so portability can be achieved. Standards and Industry support +- Proprietary (but committed to open source)

WSDL vs. Slice <definitions name="StockQuote" targetNamespace=" xmlns:tns=" xmlns:xsd1=" xmlns:soap=" xmlns=" <schema targetNamespace=“ xmlns=" My first service // My first service interface StockQuoteService { float GetLastTradePrice(string tickerSymbol); };

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

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

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

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

Site Architecture

Site Deployment Modes

Simple VO Setup

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

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

Client Programming Model // create client session ClientSession session = new ClientSessionImpl(communicator()); // create service reference ServiceReference ref = ServiceReferenceFactory.create( 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);

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

Thank you! For more information: Oleg Sukhoroslov,

Basic IARnet2 Components