RAGUL.R.R rajkumar - Academia.edu (original) (raw)
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Papers by RAGUL.R.R rajkumar
In this paper we focus on two practical considerations that arise in the design of a real-time fi... more In this paper we focus on two practical considerations that arise in the design of a real-time filesystem. Firstly, disk bandwidth management should be dynamic, which in turn would allow a QoS manager to dynamically reallocate disk bandwidth to running applications based on their changing needs. Secondly, real-time access to file system data structures should be deterministic, in order to avoid unexpected latencies when accessing files from disk. These issues have implications to the design of the filesystem and to its schedulability analysis. We address both these problems and present an implementation in RTFS (Real-Time Filesystem Server), a real-time filesystem supporting disk bandwidth reservation running on top of the Real-Time Mach microkernel. Finally, quantitative comparisons of actual achieved filesystem bandwidth and response times are used to validate our approach.
Real-time and multimedia applications like m ulti-party collaboration, internet telephony and dis... more Real-time and multimedia applications like m ulti-party collaboration, internet telephony and distributed command control systems require the exchange of information over distributed and heterogeneous nodes. Multiple data types including voice, video, sensor data, real-time intelligence data and text are being transported widely across today's information, control and surveillance networks. All such applications can bene t enormously from middleware, operating system and networking services that can support QoS guarantees, high availability, dynamic recon gurability and scalability. In this paper, we propose a middleware layer called the Real-Time Push-Pull Communications Service" to easily and quickly disseminate information across heterogeneous nodes with exible communication patterns. Realtime push-pull communications is an extension of the real-time publisher subscriber model, and represents both push" data transfer initiated by a sender and pull" data transfer initiated by a receiver communications. Nodes with widely di ering processing power and networking bandwidth can coordinate and co-exist by the provision of appropriate and automatic support for transformation on data. In particular, unlike the real-time publisher subscriber model, di erent information sources and sinks can operate at di erent frequencies and also can choose another intermediate node to act as their proxy and and deliver data at the desired frequency. I n addition to the synchronous communications of the publisher-subscriber model, information sinks can also choose to obtain data asynchronously. This service has been implemented on RT-Mach, a resource-centric kernel using resource kernel primitives 7. This paper presents an overview of the design, implementation and a performance evaluation of the model. We also test the applicability and versatility of this service using RT-Conference, a m ulti-party m ultimedia collaboration application built on top of this model. Finally, w e summarize some key lessons learned in this process.
In this paper we focus on two practical considerations that arise in the design of a real-time fi... more In this paper we focus on two practical considerations that arise in the design of a real-time filesystem. Firstly, disk bandwidth management should be dynamic, which in turn would allow a QoS manager to dynamically reallocate disk bandwidth to running applications based on their changing needs. Secondly, real-time access to file system data structures should be deterministic, in order to avoid unexpected latencies when accessing files from disk. These issues have implications to the design of the filesystem and to its schedulability analysis. We address both these problems and present an implementation in RTFS (Real-Time Filesystem Server), a real-time filesystem supporting disk bandwidth reservation running on top of the Real-Time Mach microkernel. Finally, quantitative comparisons of actual achieved filesystem bandwidth and response times are used to validate our approach.
Real-time and multimedia applications like m ulti-party collaboration, internet telephony and dis... more Real-time and multimedia applications like m ulti-party collaboration, internet telephony and distributed command control systems require the exchange of information over distributed and heterogeneous nodes. Multiple data types including voice, video, sensor data, real-time intelligence data and text are being transported widely across today's information, control and surveillance networks. All such applications can bene t enormously from middleware, operating system and networking services that can support QoS guarantees, high availability, dynamic recon gurability and scalability. In this paper, we propose a middleware layer called the Real-Time Push-Pull Communications Service" to easily and quickly disseminate information across heterogeneous nodes with exible communication patterns. Realtime push-pull communications is an extension of the real-time publisher subscriber model, and represents both push" data transfer initiated by a sender and pull" data transfer initiated by a receiver communications. Nodes with widely di ering processing power and networking bandwidth can coordinate and co-exist by the provision of appropriate and automatic support for transformation on data. In particular, unlike the real-time publisher subscriber model, di erent information sources and sinks can operate at di erent frequencies and also can choose another intermediate node to act as their proxy and and deliver data at the desired frequency. I n addition to the synchronous communications of the publisher-subscriber model, information sinks can also choose to obtain data asynchronously. This service has been implemented on RT-Mach, a resource-centric kernel using resource kernel primitives 7. This paper presents an overview of the design, implementation and a performance evaluation of the model. We also test the applicability and versatility of this service using RT-Conference, a m ulti-party m ultimedia collaboration application built on top of this model. Finally, w e summarize some key lessons learned in this process.