Load Balancing for Flow-based Parallel Processing Systems in CMP Architecture

Load balancing is critical to the performance of parallel processing systems. It is more difficult for network systems such as NIDS and Web Servers, because they must preserve flow order. But traditional flow-based load balancing schemes of network parallel processing systems, such as LLF, cost much resource and introduce lots of communication overhead. With the rapid popularization of multi-core system, it is a good choice to apply NIDS in CMP architecture to achieve higher performance. Some companies have taken the first step. Their scheduling algorithm operates at a custom NIC based on FPGA technology. LLF algorithm can't be used in such environment because it needs much more memory than NIC owns. In this paper, we propose a scheduling scheme that re-maps the new arrival flows when the system is unbalanced. To make effective adjustments we design a new triggering policy based on waiting lengths and their difference. Compared with LLF, our algorithm costs about 5% memory to get the same performance.