With the rapid improvement of computation capability in high performance supercomputer system, the imbalance of performance between computation subsystem and storage subsystem has become more and more serious, especia...With the rapid improvement of computation capability in high performance supercomputer system, the imbalance of performance between computation subsystem and storage subsystem has become more and more serious, especially when various big data are produced ranging from tens of gigabytes up to terabytes. To reduce this gap, large-scale storage systems need to be designed and implemented with high performance and scalability. MilkyWay-2 （TH-2） supercomputer system with peak performance 54.9 Props, definitely has this kind of requirement for storage system. This paper mainly introduces the storage system in MilkyWay-2 supercomputer, including the hardware architecture and the parallel file system. The storage system in MilkyWay-2 supercomputer exploits a novel hybrid hierarchy storage architecture to enable high scalability of I/O clients, I/O bandwidth and storage capacity. To fit this architecture, a user level virtualized file system, named H^2FS, is designed and implemented which can cooperate local storage and shared storage together into a dynamic single namespace to optimize I/O performance in IO-intensive applications. The evaluation results show that the storage system in MilkyWay-2 supercomputer can satisfy the critical requirements in large scale supercomputer, such as performance and scalability.展开更多
Modern solid-state drives (SSDs)are integrating more internal resources to achieve higher capacity.Parallelizing accesses across internal resources can potentially enhance the performance of SSDs.However,exploiting pa...Modern solid-state drives (SSDs)are integrating more internal resources to achieve higher capacity.Parallelizing accesses across internal resources can potentially enhance the performance of SSDs.However,exploiting parallelism inside SSDs is challenging owing to real-time access conflicts.In this paper,we propose a highly parallelizable I/O scheduler (PIOS)to improve internal resource utilization in SSDs from the perspective of I/O scheduling.Specifically, we first pinpoint the conflicting flash requests with precision during the address translation in the Flash Translation Layer (FTL).Then,we introduce conflict eliminated requests (CERs)to reorganize the I/O requests in the device-level queue by dispatching conflicting flash requests to different CERs.Owing to the significant performance discrepancy between flash read and write operations,PIOS employs differentiated scheduling schemes for read and write CER queues to always allocate internal resources to the conflicting CERs that are more valuable.The small dominant size prioritized scheduling policy for the write queue significantly decreases the average write latency.The high parallelism density prioritized scheduling policy for the read queue better utilizes resources by exploiting internal parallelism aggressively.Our evaluation results show that the paralle/izable I/O scheduler (PIOS)can accomplish better SSD performance than existing I/O schedulers implemented in both SSD devices and operating systems.展开更多
Exosomal glycoproteins play significant roles in many physiological and pathological procedures. However, the current methods for studying exosomal glycoproteins have low sensitivity or can affect exosomal biological ...Exosomal glycoproteins play significant roles in many physiological and pathological procedures. However, the current methods for studying exosomal glycoproteins have low sensitivity or can affect exosomal biological function. Herein, we developed a proximity dual-tagging strategy using an induced hybridization chain reaction(HCR) from the target’s non-functional epitope for amplified visualization and functional exploration of exosomal protein-specific glycosylation. This strategy leverages dualtagging based on the aptamer with little influence on target function and metabolic glycan labelling, and the rigid product and high sensitivity of HCR. The method improves the signal of visualizing exosomal PD-L1(exo PD-L1) by 7.7-fold compared with the signal without HCR amplification without affecting the natural exo PD-L1/PD-1 interaction. As a result, we verified that the interaction between exo PD-L1 and PD-1 positive cells is positively correlated to the glycosylation level of exo PD-L1. Overall,we have developed a sensitive method with little functional influence to visualize exosomal protein-specific glycosylation in situ,offering a powerful tool for studying the biological implications of exosomal glycoproteins.展开更多
To investigate the deformation mechanisms of rock under hydrostatic stress, destructive experiments were conducted on sandstone under different levels of hydrostatic stress and stress Lode angles. The results reveal t...To investigate the deformation mechanisms of rock under hydrostatic stress, destructive experiments were conducted on sandstone under different levels of hydrostatic stress and stress Lode angles. The results reveal that the shape of the strength envelope on the π plane gradually changes from the shape of the Lade criterion to the shape of the Drucker-Prage criterion with an increase in hydrostatic stress.Normally, there exists a deviation between the strain and stress paths for porous rocks on the π plane,and the deviation decreases with an increase in stress Lode angle and hydrostatic stress. A rock failure hypothesis based on the rock porous structure was proposed to investigate the reasons for the abovementioned phenomena. It was found that the shear expansion in the minimum principal stress direction is the dominant factor affecting the Lode angle effect(LAE);the magnitude of the hydrostatic stress induces the variation of the porous structure and influences the shear expansion. Therefore, the hydrostatic stress state affects the LAE. The failure hypothesis proposed in this paper can clarify the hydrostatic stress effect, LAE, and the variation of the rock strength envelope shape.展开更多
基金Acknowledgements This work was supported by the National High-Tech Research ＆ Development Program of China （863 Program） （2012AA01A301）, and by the National Natural Science Foundation of China （Grant Nos. 61120106005, 61202118, 61303187）.
文摘With the rapid improvement of computation capability in high performance supercomputer system, the imbalance of performance between computation subsystem and storage subsystem has become more and more serious, especially when various big data are produced ranging from tens of gigabytes up to terabytes. To reduce this gap, large-scale storage systems need to be designed and implemented with high performance and scalability. MilkyWay-2 （TH-2） supercomputer system with peak performance 54.9 Props, definitely has this kind of requirement for storage system. This paper mainly introduces the storage system in MilkyWay-2 supercomputer, including the hardware architecture and the parallel file system. The storage system in MilkyWay-2 supercomputer exploits a novel hybrid hierarchy storage architecture to enable high scalability of I/O clients, I/O bandwidth and storage capacity. To fit this architecture, a user level virtualized file system, named H^2FS, is designed and implemented which can cooperate local storage and shared storage together into a dynamic single namespace to optimize I/O performance in IO-intensive applications. The evaluation results show that the storage system in MilkyWay-2 supercomputer can satisfy the critical requirements in large scale supercomputer, such as performance and scalability.
文摘Modern solid-state drives (SSDs)are integrating more internal resources to achieve higher capacity.Parallelizing accesses across internal resources can potentially enhance the performance of SSDs.However,exploiting parallelism inside SSDs is challenging owing to real-time access conflicts.In this paper,we propose a highly parallelizable I/O scheduler (PIOS)to improve internal resource utilization in SSDs from the perspective of I/O scheduling.Specifically, we first pinpoint the conflicting flash requests with precision during the address translation in the Flash Translation Layer (FTL).Then,we introduce conflict eliminated requests (CERs)to reorganize the I/O requests in the device-level queue by dispatching conflicting flash requests to different CERs.Owing to the significant performance discrepancy between flash read and write operations,PIOS employs differentiated scheduling schemes for read and write CER queues to always allocate internal resources to the conflicting CERs that are more valuable.The small dominant size prioritized scheduling policy for the write queue significantly decreases the average write latency.The high parallelism density prioritized scheduling policy for the read queue better utilizes resources by exploiting internal parallelism aggressively.Our evaluation results show that the paralle/izable I/O scheduler (PIOS)can accomplish better SSD performance than existing I/O schedulers implemented in both SSD devices and operating systems.
基金supported by the National Natural Science Foundation of China (22022409, 21735004, 21874089)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13036)+1 种基金the National Science Fund for Fostering Talents in Basic Science (J1310024)XMU Training Program of Innovation and Entrepreneurship for Undergraduates。
文摘Exosomal glycoproteins play significant roles in many physiological and pathological procedures. However, the current methods for studying exosomal glycoproteins have low sensitivity or can affect exosomal biological function. Herein, we developed a proximity dual-tagging strategy using an induced hybridization chain reaction(HCR) from the target’s non-functional epitope for amplified visualization and functional exploration of exosomal protein-specific glycosylation. This strategy leverages dualtagging based on the aptamer with little influence on target function and metabolic glycan labelling, and the rigid product and high sensitivity of HCR. The method improves the signal of visualizing exosomal PD-L1(exo PD-L1) by 7.7-fold compared with the signal without HCR amplification without affecting the natural exo PD-L1/PD-1 interaction. As a result, we verified that the interaction between exo PD-L1 and PD-1 positive cells is positively correlated to the glycosylation level of exo PD-L1. Overall,we have developed a sensitive method with little functional influence to visualize exosomal protein-specific glycosylation in situ,offering a powerful tool for studying the biological implications of exosomal glycoproteins.
文摘To investigate the deformation mechanisms of rock under hydrostatic stress, destructive experiments were conducted on sandstone under different levels of hydrostatic stress and stress Lode angles. The results reveal that the shape of the strength envelope on the π plane gradually changes from the shape of the Lade criterion to the shape of the Drucker-Prage criterion with an increase in hydrostatic stress.Normally, there exists a deviation between the strain and stress paths for porous rocks on the π plane,and the deviation decreases with an increase in stress Lode angle and hydrostatic stress. A rock failure hypothesis based on the rock porous structure was proposed to investigate the reasons for the abovementioned phenomena. It was found that the shear expansion in the minimum principal stress direction is the dominant factor affecting the Lode angle effect(LAE);the magnitude of the hydrostatic stress induces the variation of the porous structure and influences the shear expansion. Therefore, the hydrostatic stress state affects the LAE. The failure hypothesis proposed in this paper can clarify the hydrostatic stress effect, LAE, and the variation of the rock strength envelope shape.
