DataGrid is a project funded by the European Commission EDG Conference, Heidelberg, Sep 26 – Oct under contract IST OGSI and GT3 Initial Experiences

EDG Conference, Heidelberg, Sep 26 - Oct – n° 2 Contents u Understanding OGSA/OGSI u Grid Services u Globus Toolkit 3 u Performance Results u Conclusions

EDG Conference, Heidelberg, Sep 26 - Oct – n° 3 Understanding OGSA/OGSI u Web Services n Provide interoperability for services interaction n XML, SOAP, WSDL u Open Grid Service Architecture n Integrates grid technologies with Web Services n Defines the key components of the grid u Open Grid Service Infrastructure n Formal and technical specification of the services described in OGSA n Defines interfaces for interaction with and between Grid Services GRID SERVICES OGSA OGSI WEB SERVICES EXTEND DEFINE SPECIFY

EDG Conference, Heidelberg, Sep 26 - Oct – n° 4 Grid Services u Core Architecture COMPLEMENTARYOGSI IMPL. GRID SERVICES WEB SERVICES ENGINE GRID CONTAINER HOSTING ENVIRONMENT u Current options n Hosting Environments & OGSI Implementations: s J2EE Application Servers -> Globus Toolkit 3 s Microsoft.NET Platform -> OGSI.NET, MS.NETGrid n Others will appear: s Any environment with a Web Services engine available is one step away from providing Grid Services s Some efforts started: OGSI::Lite (Perl), pyGridWare (Python)

EDG Conference, Heidelberg, Sep 26 - Oct – n° 5 Grid Services u Dummy Service example to demonstrate: n Factories and Instances u Web Service Extensions n Service Data s Each Grid Service has a set of Service Data Elements n Interface Inheritance n Lifecycle Management u Services may be persistent or transient DUMMY SERVICE FACTORY CLIENT DUMMY INSTANCE n Notifications SDE 1SDE 2 GRID SERVICE Y REQUEST NEW INSTANCE INSTANTIATE INSTANCE INVOKE REMOTE METHOD SUBSCRIPTION TO SDE NOTIFICATIONS

EDG Conference, Heidelberg, Sep 26 - Oct – n° 6 Globus Toolkit 3 u Provides complete implementation of the OGSI specification u Complementary Services: Security n GSI3 – extension of GSI2 providing: s Message-Level Security: XML Signature and XML Encryption s Transport-Level Security – deprecated u Higher Level Services n Resource Management s MMJFS – GT2 GRAM with a Grid Service interface n Data Management s GT2 GridFTP s Reliable File Transfer Service – RFT s Replica Location Service – RLS n Information Services s MDS3 – information aggregation and registry s GT2 MDS2 – ldap interface s Although both implementations are offered in GT3, they are independent so one knows nothing about the existence of the other

EDG Conference, Heidelberg, Sep 26 - Oct – n° 7 Globus Toolkit 3 u Components to deploy a Grid Service n Service Interface – GWSDL (WSDL Extended) s Manually written or generated from existing Java code n Service Implementation s Directly extending a basic Grid Service or using delegation n Deployment Descriptor s Defined in WSDD (Web Service Deployment Descriptor) n Build File s Used by the Apache Ant tool for compilation (and deployment)

EDG Conference, Heidelberg, Sep 26 - Oct – n° 8 Performance Measurements u Hardware: 2 * Pentium III 600mhz processors, 256mb RAM u Dummy Service Performance n Setup 1 s Client calls Dummy Service Factory to create a new Instance s Client invokes two methods on the instance created s Client destroy the instance n Setup 2 s Same as setup one but in the second step each method is invoked 100 times n Up to 1000 clients were used from up to 45 different client nodes n Security was tried using instructions from the Globus page s GSI Secure Conversation with XML Signature

EDG Conference, Heidelberg, Sep 26 - Oct – n° 9 Performance Measurements setupauthentication service containersaturation throughput average CPU u+s usage, % 1-GT3 standalone 41 services/s89 1 yesGT3 standalone1.3 services/s88 1-Tomcat60 services/s89 1 yesTomcat1.2 services/s88 2-GT3 standalone 300 method calls/s96 2 yesGT3 standalone10 method calls/s72 2-Tomcat290 method calls/s96 2YesTomcat13 method calls/s79 u Dummy Service Performance n Preliminary Results u Conclusions: n Security overhead needs further investigation n Tomcat can be from a bit slower to 50% faster n Some additional tests on more powerful machines should be done

EDG Conference, Heidelberg, Sep 26 - Oct – n° 10 Performance Measurements u Dummy Service Performance

EDG Conference, Heidelberg, Sep 26 - Oct – n° 11 Performance Measurements u Index Service Performance n Setup 1 (push) s Notification mechanism is used s Index Service acts as a Notification Source s Multiple Notification Sinks subscribe to the ‘Host’ SDE n Setup 2 (pull) s Multiple clients querying the Index Service using ogsi-find-service-data s Clients run in parallel n No security is used in either setup setup service container saturation throughput average CPU u+s usage, % 1GT3 standalone notifications/s81 – 87 1Tomcat- 2GT3 standalone200 requests/s88 2Tomcat200 requests/s90

EDG Conference, Heidelberg, Sep 26 - Oct – n° 12 Performance Measurements u Index Service Performance

EDG Conference, Heidelberg, Sep 26 - Oct – n° 13 Conclusions u Generally impressed with GT3 and the overall concept u Major Issues: n Performance n Incomplete documentation n Several bugs found: s Core implementation related – due to framework short lifetime s From tools deployed with the framework – hard to solve (e.g. Axis) s From the outside – easier to solve (e.g. Tomcat) u System architecture must consider performance issues u Next Actions: n Understand better the performance issues on Security, Factories and Notifications n Validate the interoperability claim by trying other toolkits