RPC is one of the programming models envisioned for the Grid. In Internet connected Large Scale Grids such as Desktop Grids, nodes and networks failures are not rare events. This paper provides several contributions, examining the feasibility and limits of fault-tolerant RPC on these platforms. First, we characterize these Grids from their fundamental features and demonstrate that their applications scope should be safely restricted to stateless services. Second, we present a new fault-tolerant RPC protocol associating an original combination of three-tier architecture, passive replication and message logging. We describe RPC-V, an implementation of the proposed protocol within the XtremWeb Desktop Grid middleware. Third, we evaluate the performance of RPC-V and the impact of faults on the execution time, using a real life application on a Desktop Grid testbed assembling nodes in France and USA. We demonstrate that RPC-V allows the applications to continue their execution while key system components fail.

This paper presents design and implementation of a remote Procedure call (RPC) API for programming applications on Peer-to-Peer environments. The P2P-RPC API is designed to address one of neglected aspect of Peer-to-Peer the lack of a simple programming interface. In this paper we examine one concrete implementation of the P2P-RPC-API derived from OmniRPC (an existing RPC API for the Grid based on Ninf system). This new API is implemented on top of low-level functionalities of the XtremWeb Peer-to-Peer Computing System. The minimal API defined in this paper provides a basic mechanism to make migrate a wide variety of applications using RPC mechanism to the Peer-to-Peer systems. We evaluate P2P-RPC for a numerical application (NAS EP Benchmark) and demonstrate its performance and fault tolerance properties.

Global Computing platforms, large scale clusters and future TeraGRID systems gather thousands of nodes for computing parallel scientific applications. At this scale, node failures or disconnections are frequent events. This Volatility reduces the MTBF of the whole system in the range of hours or minutes. We present MPICH-V, an automatic Volatility tolerant MPI environment based on uncoordinated checkpoint/roll-back and distributed message logging. MPICH-V architecture relies on Channel Memories, Checkpoint servers and theoretically proven protocols to execute existing or new, SPMD and Master-Worker MPI applications on volatile nodes. To evaluate its capabilities, we run MPICH-V within a framework for which the number of nodes, Channels Memories and Checkpoint Servers can be completely configured as well as the node Volatility. We present a detailed performance evaluation of every component of MPICH-V and its global performance for non-trivial parallel applications. Experimental results demonstrate good scalability and high tolerance to node volatility.