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Showing 1 to 2 of 2 (0.027 seconds)Spelling suggestions: "subject:"anetwork cache"" "subject:"anetwork vache""
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Architectural enhancement for message passing interconnectsKhun Jush, Farshad 21 October 2008 (has links)
Research in high-performance architecture has been focusing on achieving more computing power to solve computationally-intensive problems. Advancements in the processor industry are not applicable in applications that need several hundred or thousand-fold improvement in
performance. The parallel architecture approach promises to provide more computing power and scalability. Cluster computing, consisting of low-cost and high-performance processors, has been an alternative to proprietary and expensive supercomputer platforms. As in any other
parallel system, communication overhead (including hardware, software, and network) adversely affects the computation performance in a cluster environment. Therefore, decreasing this overhead is the main concern in such environments.
Communication overhead is the key obstacle to reaching hardware performance limits and is mostly associated with software overhead, a significant portion of which is attributed to message copying. Message copying is largely caused by a lack of knowledge of the next received message, which can be dealt with through speculation. To
reduce this copying overhead and advance toward a finer granularity, architectural extensions comprised of a specialized network cache and instructions to manage the operations of these extensions were introduced. In order to investigate the effectiveness of the proposed architectural enhancement, a simulation environment was established by expanding an existing single-thread infrastructure to one that can run MPI applications. Then the proposed extensions were implemented, along with the MPI functions on top of the SimpleScalar infrastructure.
Further, two techniques were proposed in order to achieve zero-copy data transfer in message passing environments, two policies that determine
when a message is to be bound and sent to the data cache. These policies are called Direct to Cache Transfer DTCT and lazy DTCT. The simulations showed that by using the proposed network extension along with the DTCT techniques fewer data cache misses were encountered as compared to when the DTCT techniques
were not used. This involved a study of the possible overhead and cache pollution introduced by the operating system and the communications stack, as exemplified by Linux, TCP/IP and M-VIA. Then these effects on the proposed extensions were explored. Ultimately, this enabled a comparison of the performance achieved by applications running on a system incorporating the proposed extension with the performance of the same
applications running on a standard system. The results showed that the proposed approach could improve the performance of MPI applications by 15 to 20%.
Moreover, data transfer mechanisms and the associated components in the CELL BE processor were studied. For this, two general data transfer methods were explored involving the PUT and GET functions, demonstrating that the SPE-initiated DMA data transfers are faster than the corresponding PPE-initiated DMAs. The main components of each data transfer were also investigated. In the SPE-initiated GET function, the main component is data delivery. However, the PPE-initiated GET function shows a long DMA issue time as well as a lengthy gap in receiving successive messages. It was demonstrated that the main components of the SPE-initiated PUT function are data
delivery and latency (that is, the time to receive the first byte), and the main components in the PPE-initiated PUT function are the DMA issue time and latency. Further, an investigation revealed that memory-management overhead is comparable to the data transfer time;
therefore, this calls for techniques to hide the unavoidable
overhead in order to reach high-throughput communication in MPI implementation in the Cell BE processor.
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Jämförelse av cache-tjänster: WSUS Och LanCache / Comparison of cache services: WSUS and LanCacheShammaa, Mohammad Hamdi, Aldrea, Sumaia January 2023 (has links)
Inom nätverkstekniken och datakommunikationen råder idag en tro på tekniken nätverkscache som kan spara data för att senare kunna hämta hem det snabbare. Tekniken har genom åren visat att den effektivt kan skicka den önskade data till sina klienter. Det finns flera cache-tjänster som använder tekniken för Windows-uppdateringar. Bland dessa finns Windows Server Update Services (WSUS) och LanCache. På uppdrag från företaget TNS Gaming AB jämförs dessa tjänster med varandra under examensarbetet. Nätverkscache är ett intressant forskningsområde för framtida kommunikationssystem och nätverk tack vare sina fördelar. Likaså är uppgiften om att jämföra cache-tjänsterna WSUS och LanCache intressant i och med det öppnar upp insikt om vilken tjänst är bättre för företaget eller andra intressenter. Både forskningsområdet och uppgiften är viktiga och intressanta när användare vill effektivisera användningen av internetanslutningen och bespara nätverksresurser. Därmed kan tekniken minska nedladdningstiden. Till det här arbetet besvaras frågor om vilken nätverksprestanda, resursanvändning och administrationstid respektive cache-tjänst har, och vilken cache-tjänst som lämpar sig bättre för företagets behov. I arbetet genomförs experiment, som omfattar tre huvudmättningar, och följs av en enfallstudie. Syftet med arbetet är att med hjälp av experimentets mätningar få en jämförelse mellan WSUS och LanCache. Resultatet av arbetet utgör sedan ett underlag för det framtida lösningsvalet. Resultaten består av två delar. Den första visar att båda cache-tjänsterna bidrar till kortare nedladdningstider. Den andra är att LanCache är bättre än WSUS när det gäller nätverksprestanda och resursanvändning, samt mindre administrationstid jämfört med WSUS. Givet resultat dras slutsatsen att LanCache är cache-tjänsten som är mest lämpad i det här fallet. / In the field of network technology and data communication, there is a current belief in the technology of network caching, which can store data to later retrieve it more quickly. Over the years, this technology has proven its ability to efficiently deliver the desired data to its clients. There are several caching services that utilize this technology for Windows updates, among them are Windows Server Update Services (WSUS) and LanCache. On behalf of the company TNS Gaming AB, these services are compared to each other in this thesis. Network caching is an interesting area of research for future communication systems and networks due to its benefits. Likewise, the task of comparing the cache services WSUS and LanCache is interesting as it provides insights into which service is better suited for the company or other stakeholders. Both the research area and the task are important and intriguing when users seek to streamline the use of their internet connection and conserve network resources. Thus, the technology can reduce download times. For this work, questions about the network performance, resource usage, and administration time of each cache service are answered, as well as which cache service that is better suited to the company's needs. The work involves conducting experiments, including three main measurements, followed by a single case study. The purpose of the work is to compare WSUS and LanCache using the measurements from the experiment. The outcome of the work then forms a basis for future solution choice. The results consist of two parts. The first shows that both cache services contribute to shorter download times. The second is that LanCache outperforms WSUS in terms of network performance and resource usage, and also requires less administration time than WSUS. Given the results, the conclusion is drawn that LanCache is the most suitable caching service in this case.
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