利用对称多处理器提高NIDS的性能

网络入侵检测系统(NIDS)通过捕获和分析网络数据包判断是否存在攻击行为。由于网络带宽越来越高，NIDS的处理能力越来越难以跟上网络的速度。该文提出了一种利用对称多处理器(SMP)提高NIDS处理能力的方法，通过多个CPU并行的处理网络数据包改善系统的性能。经过对NIDS处理过程的分析，设计了一种有效的并行处理结构，保证在不同CPU上运行的线程能够高度并行的执行。此外，该文提出的线程同步方式既保证了程序功能的正确，又避免了对共享资源的互斥访问，进一步提高了线程的并行度。实验证明，在具有双CPU的CMP结构上实现的NIDS的性能比单CPU系统提高了80％。

Improving the performance of NIDS using symmetric multi-processor

Network-based intrusion detection system (NIDS) detects attacks by capturing and analyzing network packets. As network band increases, NIDS can hardly keep up with the speed of networks. A method of improving NIDS' process ability using symmetric multi-processor (SMP) was proposed in the paper. Several CPUs of the system were used to process network packets in parallel to improve the performance. After analyzing NIDS' process procedure, an effective parallel processing structure was devised, which guaranteed threads on different CPUs running in parallel. Moreover, the synchronization method of threads proposed avoided the mutually exclusive access to the shared resource, which further increased the parallelity of threads, and guaranteed the correctness of the functionality of the program. Experiments show that the NIDS implemented on a SMP system with dual CPUs is almost 80% faster than the one based on a system with unique CPU.