A practical evaluation of a data consistency protocol for efficient visualization in grid applications

Data visualization is important in the context of grid applications, especially when successive refinements are iteratively realized based on intermediate results. We mainly focus on code coupling grid applications, structured as a set of distributed, autonomous, weakly-coupled codes. We consider the case where the codes are able to interact using the abstraction of a shared data space. In previous work, we have proposed an efficient visualization scheme by introducing a new operation called relaxed read, as an extension to the entry consistency model. This operation can efficiently take place without locking, in parallel with write operations. On the other hand, the user has to relax the consistency constraints, and accept slightly older versions of the data, whose "freshness" can however still be controlled. In this paper, we discuss and extensively evaluate the proposed consistency protocol, whose efficiency is clearly demonstrated by our experimental results.