Net-dbx: a web-based debugger of MPI programs over low-bandwidth lines

Neophytou, Neophytos; Evripidou, Paraskevas

doi:10.1109/71.954636

Cited by 10 publications

(3 citation statements)

References 5 publications

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“…In distributed domain, both of static analysis [19] and runtime analysis [20] are presented. Runtime analysis [20] approach, generally, low level debugging information is needed for detecting faults. To reduce the runtime overhead, Ref.…”

Section: Related Workmentioning

confidence: 99%

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Online Kernel Log Analysis for Robotics Application

Sugaya

Takamura

Ishiwata

et al. 2013

Journal of Information Processing

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Humanoid robot systems are composed of an assortment of hardware and software components, and they have complex embedded systems and real-time properties. These features make it difficult to isolate or to identify a fault in a short period of time even though such systems are expected to recover quickly in order to avoid any harmful behaviors that may cause harm to the users. This paper presents a new technological method for detecting errors in real-time applications online through the technique of online kernel log monitoring and analysis method. The contributions of approaches are that we present a method for kernel log analysis based on a state transition model of scheduling tasks, and apply it to the kernel logs to detect anomaly behavior of real-time tasks. In order to reduce the analysis overhead of huge volumes of data, we propose a new system that places the kernel log analysis engine on a separate core from the one that runs the kernel log monitoring process. Based on this system, we provide a framework for writing analyzers to detect errors incrementally. In our system, these components work together to solve the problems highlighted by root cause analysis in robotic systems. We applied the proposed system to actual robotics systems and successfully detected several deviated errors and faults that include a serious priority inversion that was not detected in over 10 years of operation in the actual operating system.

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Section: Related Workmentioning

confidence: 99%

“…To reduce the runtime overhead, Ref. [20]'s Java-based tools that automate to collect debugging logs from each server and send it to debugger servers. This makes it possible to reduce the debugging cost using lowbandwidth line.…”

Section: Related Workmentioning

confidence: 99%

Online Kernel Log Analysis for Robotics Application

Sugaya

Takamura

Ishiwata

et al. 2013

Journal of Information Processing

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show abstract

“…Although useful for identifying some classes of errors, static analysis also suffers from false negatives since many parameters are not known until the application executes. Parallel debuggers operate similarly as sequential debuggers [36,31,30,28,4], but can be difficult to use effectively when there are hundreds of processes. Automatic checking tools address the drawbacks of manual checking in parallel debuggers [38,12,19,7,37].…”

Section: Related Workmentioning

confidence: 99%

MPIWiz

Xue

Liu

et al. 2009

Proceedings of the 14th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming

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Message Passing Interface (MPI) is a widely used standard for managing coarse-grained concurrency on distributed computers. Debugging parallel MPI applications, however, has always been a particularly challenging task due to their high degree of concurrent execution and non-deterministic behavior. Deterministic replay is a potentially powerful technique for addressing these challenges, with existing MPI replay tools adopting either data-replay or order-replay approaches. Unfortunately, each approach has its tradeoffs. Data-replay generates substantial log sizes by recording every communication message. Order-replay generates small logs, but requires all processes to be replayed together. We believe that these drawbacks are the primary reasons that inhibit the wide adoption of deterministic replay as the critical enabler of cyclic debugging of MPI applications.This paper describes subgroup reproducible replay (SRR), a hybrid deterministic replay method that provides the benefits of both data-replay and order-replay while balancing their trade-offs. SRR divides all processes into disjoint groups. It records the contents of messages crossing group boundaries as in data-replay, but records just message orderings for communication within a group as in order-replay. In this way, SRR can exploit the communication locality of traffic patterns in MPI applications. During replay, developers can then replay each group individually. SRR reduces recording overhead by not recording intra-group communication, and reduces replay overhead by limiting the size of each replay group. Exposing these tradeoffs gives the user the necessary control for making deterministic replay practical for MPI applications.We have implemented a prototype, MPIWIZ, to demonstrate and evaluate SRR. MPIWIZ employs a replay framework that allows transparent binary instrumentation of both library and system calls. As a result, MPIWIZ replays MPI applications with no source code modification and relinking, and handles nondeterminism in both MPI and OS system calls. Our preliminary results show that MPIWIZ can reduce recording overhead by over a factor of four relative to data-replay, yet without requiring the entire application to be replayed as in order-replay. Recording increases execution time by 27% while the application can be replayed in just 53% of its base execution time.

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Grid Service Based Parallel Debugging Environment

Wang

Fang

2006

Lecture Notes in Computer Science

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Net-dbx: a web-based debugger of MPI programs over low-bandwidth lines

Cited by 10 publications

References 5 publications

Online Kernel Log Analysis for Robotics Application

Online Kernel Log Analysis for Robotics Application

MPIWiz

Grid Service Based Parallel Debugging Environment

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