Authors: Alexey Lastovetsky, Xin Zuo, Peng Zhao Speaker: Xin Zuo

1. A Non-Intrusive and Incremental Approach to Enabling Direct Communications in RPC-based Grid Programming Systems Authors: Alexey Lastovetsky, Xin Zuo, Peng Zhao Speaker: Xin Zuo Heterogeneous Computing Laboratory (HCL) School of Computer Science and Informatics University College Dublin Ireland HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

2. Outlines • An Overview of Our Approach • Enabling direct communication in NetSolve • Architecture of the Software Component • Testing Evaluation • Conclusions/Further work HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

3. Overview of Our Approach • About High performance Grid programming • - It has reached a certain level of maturity, examples: NetSolve and Ninf • - Need further development in terms of functionality and quality. • - Addition of a new feature to a Grid programming system: • Traditionally, achieved by changing the code of the system. • - Two serious disadvantages: • 1. May introduce bugs which cause system run instable or even crash. • 2. To replace the old version, can have very high organizational overhead • and sometimes be simply unrealistic on the Grid. • The Features of our Software Component: • - Non-intrusiveness • - Increment HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

4. Overview of Our Approach • Non-intrusiveness • The original system does not change and the new features are provided by a supplementary software component working on the top of the system. • Increment • Our supplementary software component does not have to be installed on all computers to enable applications with the new features. • To demonstrate the feasibility of our approach • - We choose NetSolve • - One particular feature: Direct Communication between remote tasks • - Exact Implementation and Experiments HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

5. Enabling direct communication in NetSolve • NetSolve is positioned as a programming system for high performance distributed computing on global networks based on GridRPC. • - http://icl.cs.utk.edu/netsolve/ • -NetSolve (GridSolve),is a client-server system that enables users to solve complex scientific problems remotely • Unnecessary bridge communications: In NetSolve, output data of remote tasks are typically sent back to the client upon completion of each remote task even if the data are only needed as input for some other remote tasks. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

6. Enabling direct communication in NetSolve • Enabling direct communication HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

7. Enabling direct communication in NetSolve • Using Our software component in NetSolve • - Client side: The only thing for client programmers to do is to install wrapper API and Job Name Service on the client side, then compile the client program with the wrapper library. The principle is quite easy: the programmer just replaces the input/output arguments with handlers as the input/output data. • - Procedure developers: The procedure programmers should do nothing to enable direct communications. They develop their own procedures as usual. The supplementary software component has no effect on both existing procedures and newly added procedures. • - Server administrator: To enable direct communication control on server side, the server administrator needs to register the software component as a new problem file to NetSolve. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

8. Architecture of the Software Component • About software component: Consists of three parts • - Client API &Argument Parser: Provide a uniform interface for the client to make remote procedure calls. Despite the modification on the remote side, the wrapper API allows the calls to be made in the same manner. The only difference is in the arguments that can be not only variables storing real data but also handlers. • - Server Connector: responsible for interacting with clients and other Server Connectors to enable direct communications. • - Job Name Service (JNS): responsible for registration of procedure upon its invocation during RPC call. Other procedures may send requests to the JNS to search for registered procedure. JNS is set up on the client side automatically. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

9. Architecture of the Software Component • Architecture of the supplementary software component enabling direct communications in NetSolve HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

10. Testing Evaluation • Selected computational task: • - Matrix Multiplication. • - We used 8 remote servers to perform 8 matrix multiplications. • - The client, agent and servers all were in the same Ethernet segment. • Experiment environment: • The interconnecting network is based on 100 Mbit Ethernet with a switch enabling parallel communications between computers at School of Computer Science and Informatics in University College Dublin. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

11. Testing Evaluation (a) (b) * bridge communication x direct communication (a)Time elapsed for both communication types when all communication links have the same bandwidth, 100Mb per sec. (b) Speedup due to the use of direct communications for the homogeneous communication network. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

12. Testing Evaluation (c) (d)■ bridge communication ▲ direct communication (c) Time elapsed for both communication types when communication client and servers is at the rate of 10 Mb per sec, and communication between servers is at the rate of 100 Mbit per sec. (d) Speedup due to the use of direct communications for the heterogeneous communication network. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

13. Conclusions/Further work • Conclusions: • - we have presented an approach to reducing unnecessary bridge communications in RPC-based Grid programming systems, which is non-intrusive and incremental. • - The experimental results have shown that the performance of Grid applications can be significantly improved by using our supplementary software component. • Further work: • - Apply to different RPC-based Grid programming systems, ex: Ninf. • - Evaluations on real-world applications, we have planned : (i) parallel simulated annealing using genetic crossover in protein tertiary structure prediction system, (ii) image processing using sequential algorithms, and (iii) the matrix chain product problem in general scientific computations. HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06

14. The END • http://www.cs.ucd.ie • http://hcl.ucd.ie • Thank you! HCL Group http://hcl.ucd.ieFirst International Workshop on Workflow systems in e-Science- WSES06