Packet classification algorithms have been the focus of research for the last few years, due to the vital role they play in various services based on packet forwarding. However, as the number of rules in the rule set increases, not only the preprocessing time but also the memory consumption is increasing greatly. In this paper, we first model and analyze the above issue in depth. Then, a fast, smart packet classification algorithm based on decomposition is proposed. By boundary-based rule traversal and smart rule set partitioning, both the preprocessing time and memory consumption are reduced dramatically. Experimental results show that the preprocessing time of our method achieves 8.8-time improvement at maximum compared with the PCIU and achieves about 31.5-time improvement on average compared with CutSplit for large rule sets. Meanwhile, the memory overhead is reduced by 40% at maximum and 27.5% on average compared with the PCIU.

The continuous increase in network traffic has sharply increased the demand for high-performance packet processing systems. For a high-performance packet processing system based on multi-core processors, the packet scheduling algorithm is critical because of the significant role it plays in load distribution, which is related to system throughput, attracting intensive research attention. However, it is not an easy task since the canonical flow-level packet scheduling algorithm is vulnerable to traffic locality, while the packet-level packet scheduling algorithm fails to maintain cache affinity. In this paper, we propose an adaptive throughput-first packet scheduling algorithm for DPDK-based packet processing systems. Combined with the feature of DPDK burst-oriented packet receiving and transmitting, we propose using Subflow as the scheduling unit and the adjustment unit making the proposed algorithm not only maintain the advantages of flow-level packet scheduling algorithms when the adjustment does not happen but also avoid packet loss as much as possible when the target core may be overloaded Experimental results show that the proposed method outperforms Round-Robin, HRW (High Random Weight), and CRC32 on system throughput and packet loss rate.

Nitrogen (N) deficiency has been recorded in the top surface of Tibetan Plateau. However, the variation of soil N availability across the elevational gradient in alpine forests remains poorly understood. Here, the elevational patterns and determinants of soil N composition, key N transformation processes and functional microbes across three typical mountains on the southeastern Tibetan Plateau were characterized by multiple techniques. Our results showed that soil total N and ammonium were markedly enriched in high elevation zones where a stable N release via mineralization and extremely low net nitrification were observed. Further, the increasing biological N fixation rates along the elevation driven by abiotic (i.e., high organic carbon) and biotic (i.e., key diazotrophic taxa like Bradyrhizobium, Herbaspirillum and Klebsiella) factors greatly benefited N accumulation at high elevations. Our study offers new insights into the N dynamics in alpine forests on the Tibetan Plateau under scenarios of future climate change.

Abstract:The supporting frame pedestal base construction technology plays an important role in the construction of steel structure quality of high-rise building, the attention is an important link in the construction of steel structure of the high-rise building. In this paper, the tower No. 1 CRE International Plaza is taken as the research object, to explore the optimization measures of high-rise steel structure frame column base construction technology support, hoping to provide reference to improve the quality of high-rise building.With the development of the social economy, the high-rise buildings in China stand up and become an important trend in the China's construction industry. The steel structure in the high-rise building has become more and more common, which has been widely recognized and applied, and its industrialization and commercialization trend is more obvious. Based on this, relevant personnel actively explore the optimization path of high-rise building steel structure construction quality, and further research in the aspects of steel structure reform, manufacturing, design, installation and so on, and urge high-rise steel structure to achieve a new high. At the same time, the construction technology of steel structure with complex structure and wide span is used to support the improvement of the construction quality of the high-rise buildings. As the construction process of CRE International Plaza No. 1 floor tower is taken as the research object, the application of support column base construction technology is discussed, hoping to provide reference for the better development of high-rise buildings [1].