Design and Performance of a Stand-Alone Media Server

With the development of the communication technology, the number of the mobile equipment grows rapidly. But how to maintain the consistency of the data in multiple devices has become an increasing prominent issue. In this passage, the SyncML RTK is introduced firstly. Based on this, a design and implementation of the synchronization server will be furtherly discussed. Moreover, an experiment about the server efficiency will be done. The experiment result shows that the design of the server is feasible.

Server load prediction can be utilized for load-balancing and load-sharing in distributed systems. The use of machine learning (ML) algorithms for load estimation in distributed system applications can increase the availability and performance of servers. Hence, a number of machine learning algorithms have been applied thus far for server load estimation. This study focuses on increasing the performance of game servers by accurately predicting the workload of game servers in short, medium and long term prediction situations. While doing this, various machine learning techniques have been applied and the algorithms that give the best results are presented. In terms of implementation, companies using their servers and data centers can try to increase their level of satisfaction by using these algorithms. A prediction model is developed and the estimation performances of a number of fundamental ML methods i.e., Naive Bayes (NB), Generalized Linear Model (GLM), Logistic Regression (LR), Decision Tree (DT), Random Forest (RF), Gradient Boosted Trees (GBT), Support Vector Machine (SVM), Fast Large Margin (FLM), Convolutional Neural Network CNN are analyzed. The data used during the training stage is obtained by listening to the TCP/IP packet traffic and the real-data is extracted by performing an extensive analysis of the total transferred-data that includes also the payload. In the analysis phase, the goodput is considered in order to reveal exact resource requirements. Comprehensive simulations are performed under various conditions for high accuracy performance analysis. Experimental results indicate that the proposed ML-based prediction shows promising performance in terms of load prediction when compared to the common approaches present in the literature.

We describe the design and implementation of the Exedra continuous media server, and experimentally evaluate alternative resource management policies using a prototype system that we built. Exedra has been designed to provide scalable and efficient support for variable bit-rate media streams whose compression efficiency leads to reduced storage space and bandwidth requirements in comparison to constant bit-rate streams of equivalent quality. We examine alternative disk striping policies, and quantify the benefits of innovative techniques for storage space allocation, buffer management, and resource reservation, which we developed to achieve both predictability and high-performance in handling disk and network data transfers of variable size. Additionally, we investigate the differences between diverse data replication schemes over disk arrays, and compare methods for disk access time reservation that enable tolerance of disk failures at minimal cost. Overall, we demonstrate the feasibility of building network media servers that exploit the latest advances in media compression technology towards reducing the cost of wide-scale streaming services for stored data.

Modern JVM implementations interleave execution with compilation of “hot” methods to achieve reasonable performance. Since compilation overhead impacts the execution time of the application and induces run-time pauses, we explore offloading compilation onto a compilation server. In this article, we present the design, implementation, and evaluation of a compilation server that compiles and optimizes Java bytecodes on behalf of its clients. We show that the compilation server provides the following benefits for our benchmark programs: (i) lower execution time by reducing the compilation overhead and by enabling more aggressive optimizations; (ii) lower memory allocation by eliminating allocations due to optimizing compilation and the footprint of the optimizing compiler; (iii) lower execution time of the application due to sharing of profile information across different runs of the same application and runs of different applications. We implemented the compilation server in Jikes RVM, and our results indicate that it can reduce running time by an average of 20.5%, interruptions due to compilation by an average of 81.0%, and dynamic memory allocation by 8.6% for our benchmark programs. Simulation results indicate that our current implementation of the compilation server can handle more than 50 concurrent clients while still allowing them to outperform the best performing adaptive configuration.

This paper describes the design and implementation of a file server for variable bit rate continuous media. Most continuous media file servers have been designed for constant bit rate streams. We address the problem of building a server where each stream may have a different bit rate and, more importantly, where the bit rate within a single stream may vary considerably. Such servers will be come increasingly more important because of Variable Bit Rate (VBR) compression standards such as MPEG-2.

This paper presents the design and implementation of the Terminal Device Driver Server (TDDS), which runs on top of Chorus microkernel at the communication connection node of the SPAX multi-computer. The correctness of our design and implementation have been proved through a variety of tests. We believe that our experiences would be very helpful to the serverization of other STREAMS-based device drivers such as networking device drivers.KeywordsProcessing NodeDevice DriverDistribute Operating SystemBlock DeviceCrossbar SwitchThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

In order to realize the high precision indoor positioning system, an embedded gateway is designed for data transmission and forwarding, and the server is developed on Windows platform for storing data, obtaining and showing location information. The indoor positioning system architecture is given, focusing on the design and implementation of gateway and server. ARM11 processor is used to design a gateway. Gateway architecture and software development are introduced. A server solution is described. The results show that the designed gateway and server meet the requirements of data transmission and good positioning accuracy.

This paper describes the design and implementation of a file server for variable bit rate continuous media. Most continuous media file servers have been designed for constant bit rate streams. We address the problem of building a server where each stream may have a different bit rate and, more importantly, where the bit rate within a single stream may vary considerably. Such servers will become increasingly more important because of Variable Bit Rate compression standards such as is possible with MPEG-2.

Remote control networks have become a key area of research within wireless communication technology. Zigbee technology fills the gap in the market for low-cost, low-power wireless solutions. This paper presents the design and application of a wireless sensor network web server based on the S3C2410 microcontroller and the Zigbee protocol. The server enables real-time monitoring and control of remote objects. Using a B/S architecture and modular design approach, both hardware and software components are detailed, with an emphasis on key implementation techniques. The system has been demonstrated to operate stably with excellent scalability, making it suitable for applications in smart homes, monitoring systems, industrial control, and other domains.

MODIS data are currently widely applied in the scientific research covering the global or regional in the real-time Earth observation and disaster and environmental monitoring. However, some issues such as large data volume and complex storage format impede MODIS data's direct circulation and use, and the introduction of the WCS can foster MODIS data's dissemination and application. Facing the application requirement of the Wuhan University MODIS satellite data ground receiving station, this paper firstly analyze the characteristics of MODIS data and WCS, according to OGC WCS specification, fulfill the design and implement of a MODIS data WCS Server. This paper expatiated the design thoughts, the key technologies and implementation results.

A multi-channel stereo reproducing apparatus which is capable of favorably reproducing sounds from both a recording medium in which are recorded multi-channel stereo signals of which high-frequency components of rear signals are pre-emphasized and a recording medium in which are recorded ordinary two-channel stereo signals based upon a so-called DolbyR system, such as an audio disk or the like, so that pictures and sounds reproduced, for example, in a theatre or a cinema house can be enjoyed at home. If a left front signal is denoted by LF, a right front signal by RF, a central front signal by F, and a rear signal by B, these signals are encoded into a left composite signal LT = LF + F/2 + B/2 and a right composite signal RT = RF + F/2 - B/2, and high-frequency components of the rear signal B are pre-emphasized and are recorded onto a recording medium that is to be reproduced by the multi-channel stereo reproducing apparatus. During the reproduction of sounds from the recording medium in which are recorded two-channel stereo signals consisting of right and left front signals RF and LF only in which neither central front signal F nor rear signal B have been encoded, a de-emphasis circuit is by-passed.

To support a wide variety of service scenarios including NAT traversal, lawful interception or transcoding, a VoIP provider has to not only use signaling servers but also media servers. To reduce the load on the provider in terms of bandwidth usage and reduce the effects of adding media processing servers in the media path, the media servers should be located in the proximity of the users. In this paper we investigate the possibility of using IP anycast for enabling users to detect and use media servers in their proximity. We propose four different approaches and give a high level evaluation of the pros and cons of each approach.

The paper discusses the architecture and performance of a prototype RISC multi-processor server designed for a business system like OLTP (online transaction processing). The combination of a low-latency cache-to-cache copy and an 8-way highly interleaved main memory realize high performance for the OLTP program. We analyzed the activity of the multi-processor system when executing the OLTP program by using the trace-driven simulator including kernel execution. The main findings are that: cache misses due to task migration and ping-ponging of kernel shared data occupy a larger part of the total misses, especially in a large cache capacity because of intensive I/O activities; and the low-latency cache-to-cache copy is very effective because 50-60% of the data read accesses are supplied by the cache-to-cache copy in a large cache capacity. >

Performance study of data layout schemes for a SAN-based video server

In many distributed systems concurrent access is required to a shared object, where abstract object servers may incorporate type-specific properties to define consistency requirements. Each operation and its outcome is treated as an event, and conflicts may occur between different event types. Hence concurrency control and synchronization are required at the granularity of conflicting event types. With such a fine granularity of locking, the occurrence of conflicts is likely to be lower than with whole-object locking, so optimistic techniques become more attractive. This work describes the design, implementation, and performance of servers for a shared atomic object, a semiqueue, where each server employs either pessimistic or optimistic locking techniques on each conflicting event type. We compare the performance of a purely optimistic server, a purely pessimistic server, and a hybrid server which treats certain event types optimistically and others pessimistically, to demonstrate the most appropriate environment for using pessimistic, optimistic, or hybrid control. We show that the advantages of low overhead on optimistic locking at low conflict levels is offset at higher conflict levels by the wasted work done by aborted transactions. To achieve optimum performance over the whole range of conflict levels, an adaptable server is required, whereby the treatment of conflicting event types can be changed dynamically between optimistic and pessimistic, according to various criteria depending on the expected frequency of conflict. We describe our implementations of adaptable servers which may allocate concurrency control strategy on the basis of state information, the history of conflicts encountered, or by using preset transaction priorities. We show that the adaptable servers perform almost as well as the best of the purely optimistic, pessimistic, or hybrid servers under the whole range of conflict levels, showing the versatility and efficiency of the dynamic servers. Finally we outline a general design methodology for implementing adaptable concurrency control in servers for atomic objects, illustrated using an atomic shared B-tree.