Execution performance is critical for large-scale and data-intensive workflows. This paper proposes DISWOP, a novel scheduling algorithm for data-intensive workflow optimizations; it consists of three main steps: workflow process generation, task & resource mapping, and task clustering. To evaluate the effectiveness and efficiency of DISWOP, a comparison evaluation of different workflows is conducted a prototype workflow platform. The results show that DISWOP can speed up execution performance by about 1.6-2.3 times depending on the task scale.

Shared-Memory Optical Packet (SMOP) switch architecture is very promising for significantly reducing the amount of required optical memory, which is typically constructed from fiber delay lines (FDLs). The current reservation-based scheduling algorithms for SMOP switches can effectively utilize the FDLs and achieve a low packet loss rate by simply reserving the departure time for each arrival packet. It is notable, however, that such a simple scheduling scheme may introduce a significant packet out of order problem. In this paper, we first identify the two main sources of packet out of order problem in the current reservation-based SMOP switches. We then show that by introducing a "last-timestamp" variable and modifying the corresponding FDLs arrangement as well as the scheduling process in the current reservation-based SMOP switches, it is possible to keep packets in-sequence while still maintaining a similar delay and packet loss performance as the previous design. Finally, we further extend our work to support the variable-length burst switching.

We focus on non-conflicting construction of an optical multistage feedforward network to emulate the N-to-1 output buffer multiplexer by using switched fiber delay line (SDL). In [1], Y.T. Chen et al. presented a sufficient condition (an upper bound) for the number of delay lines required for such a multiplexer with variable length bursts. In this paper, we first give an improved upper bound. Then we develop a framework to construct an arrival case of bursts which can be used to achieve a necessary condition (a lower bound). These results are further extended to the feedforward construction of N-to-N output buffer switch. Through simulation and performance comparison, we find that the new bounds can significantly decrease the hardware cost for constructing both the feedforward SDL-based multiplexer and output buffer switch while still provide the same performance as that of the old ones.