Runtime Monitoring Tool Research Articles

ZoneTrace: A Zone Monitoring Tool for F2FS on ZNS SSDs

We present ZoneTrace , a runtime monitoring tool for the Flash-Friendly File System (F2FS) on Zoned Namespace (ZNS) SSDs. ZNS SSD organizes its storage into zones of sequential write access. Due to ZNS SSD’s sequential write nature, F2FS is a log-structured file system that has recently been adopted to support ZNS SSDs. To present the space management with the zone concept between F2FS and the underlying ZNS SSD, we developed ZoneTrace , a tool that enables users to visualize and analyze the space management of F2FS on ZNS SSDs. ZoneTrace utilizes the extended Berkeley Packet Filter (eBPF) to trace the updated segment bitmap in F2FS and visualize each zone space usage accordingly. Furthermore, ZoneTrace is able to analyze on file fragmentation in F2FS and provides users with informative fragmentation histogram to serve as an indicator of file fragmentation. Using ZoneTrace ’s visualization, we are able to identify the current F2FS space management scheme’s inability to fully optimize space for streaming data recording in autonomous systems, which leads to serious file fragmentation on ZNS SSDs. Our evaluations show that ZoneTrace is lightweight and assists users in getting useful insights for effortless monitoring on F2FS with ZNS SSD with both synthetic and realistic workloads. We believe ZoneTrace can help users analyze F2FS with ease and open up space management research topics with F2FS on ZNS SSDs.

Dynamic Evaluation of Microservice Granularity Adaptation

Microservices have gained acceptance in software industries as an emerging architectural style for autonomic, scalable, and more reliable computing. Among the critical microservice architecture design decisions is when to adapt the granularity of a microservice architecture by merging/decomposing microservices. No existing work investigates the following question: How can we reason about the trade-off between predicted benefits and cost of pursuing microservice granularity adaptation under uncertainty? To address this question, we provide a novel formulation of the decision problem to pursue granularity adaptation as a real options problem. We propose a novel evaluation process for dynamically evaluating granularity adaptation design decisions under uncertainty. Our process is based on a novel combination of real options and the concept of Bayesian surprises. We show the benefits of our evaluation process by comparing it to four representative industrial microservice runtime monitoring tools, which can be used for retrospective evaluation for granularity adaptation decisions. Our comparison shows that our process can supersede and/or complement these tools. We implement a microservice application—Filmflix—using Amazon Web Service Lambda and use this implementation as a case study to show the unique benefit of our process compared to traditional application of real options analysis.

A model-based architecture for interactive run-time monitoring

We present a model-based architecture for monitoring executions of models of real-time and embedded systems. This architecture is highly configurable and allows for the combination of various run-time monitoring tools, not only for observing the system execution, but also for interacting with it. Using a variety of case studies, we illustrate the use of the architecture for connecting the code generated from a model with a range of external tools for different purposes, including execution animation and run-time verification. However, the external tool can not only consume information from the execution, but also generate input for it and thus influence and steer it.

Performance-aware load shedding for monitoring events in container based environments

Runtime monitoring tools have become fundamental to assess the correct operation of complex systems and applications. Unfortunately, the more precise is the monitoring (sampling rate, information granularity, and so on), the higher is the overhead introduced in the system itself. In this paper, we propose a new load shedding framework that enables runtime adaptation of monitoring agents under heavy system load, exploiting an heuristic Load Manager to control the agent status and a runtime support for domain-specific policies. We implemented the proposed methodology on Sysdig, with an average control error improvement of 3.51x (12.25x at most), w.r.t. previous solutions.

A Survey of Runtime Monitoring Instrumentation Techniques

Runtime Monitoring is a lightweight and dynamic verification technique that involves observing the internal operations of a software system and/or its interactions with other external entities, with the aim of determining whether the system satisfies or violates a correctness specification. Compilation techniques employed in Runtime Monitoring tools allow monitors to be automatically derived from high-level correctness specifications (aka. properties). This allows the same property to be converted into different types of monitors, which may apply different instrumentation techniques for checking whether the property was satisfied or not. In this paper we compare and contrast the various types of monitoring methodologies found in the current literature, and classify them into a spectrum of monitoring instrumentation techniques, ranging from completely asynchronous monitoring on the one end and completely synchronous monitoring on the other.

Lightweight runtime checking of C programs with RTC

The C Programming Language is known for being an efficient language that can be compiled on almost any architecture and operating system. However the absence of dynamic safety checks and a relatively weak type system allows programmer oversights that are hard to spot. In this paper, we present RTC, a runtime monitoring tool that instruments unsafe code and monitors the program execution. RTC is built on top of the ROSE compiler infrastructure. RTC finds memory bugs and arithmetic overflows and underflows, and run-time type violations. Most of the instrumentations are directly added to the source file and only require a minimal runtime system. As a result, the instrumented code remains portable. In tests against known error detection benchmarks, RTC found 98% of all memory related bugs and had zero false positives. In performance tests conducted with well known algorithms, such as binary search and MD5, we determined that our tool has an average run-time overhead rate of 9.7× and memory overhead rate of 3.5×.

DAEH: A Tool for Specifying and Monitoring the Exception Handling Policy

The exception handling policy of a system comprises the set of design rules that specify its exception handling behavior (how exceptions should be handled and thrown). Such policy is usually undocumented and implicitly defined by the system architect. For this reason, developers often consider that by just including catch-blocks in the code they are dealing with exceptional conditions. This lack of information may turn the exception handling into a generalized “goto” mechanism making the program more complex and less reliable. This work presents a domain-specific language called ECL (Exception Contract Language) to specify the exception handling policy and a runtime monitoring tool which dynamically checks this policy. The monitoring tool is implemented in the form of an aspect library, which can be added to any Java system without the need to change the application source code. We applied this approach to two large-scale web-based systems and to a set of versions of the well-known JUnit framework. The results indicate that this approach can be used to express and to automatically check the exception handling policy of a system, and consequently support the development of more robust Java systems.

A Generic Software Monitoring Model and Features Analysis

Software runtime monitoring has been used to increase the dependability of software. This paper focuses on software runtime monitoring techniques and tools. A generic software runtime monitoring model is presented, which consists of five basic elements, i.e., Monitored Object Features, Monitoring Access Methods, Execution Relationships, Runtime Monitor and Platform Dependencies. This model is an innovation in software monitoring fields. This paper gives some features of each element. Based on these features, researchers can use the model to comprehend and analyze runtime monitoring techniques and tools. The objective of this paper is to help researchers and users to identify the difference and the basic principles of software runtime monitoring techniques and tools. This paper also shows a result of relationship between techniques and features, through the result, we can understand the development trends of the techniques and tools, such as, what features are concerned more, and what features are concerned less.

Monitoring Interfaces for Faults

We consider the problem of a module interacting with an external interface (environment) where the interaction is expected to satisfy some system specification Φ. While we have the full implementation details of the module, we are only given a partial external specification for the interface. The interface specification being partial (incomplete) means that the interface displays only a strict subset of the behaviors allowed by the interface specification.Based on the assumption that interface specifications are typically incomplete, we address the question of whether we can tighten the interface specification into a strategy, consistent with the given partial specification, that will guarantee that all possible interactions resulting from possible behaviors of the module will satisfy the system specification Φ. We refer to such a tighter specification as Φ-guaranteeing specification. Rather than verifying whether the interface, which is often an off-the-shelf component, satisfies the tighter specification, the paper proposes a construction of a run-time monitor which continuously checks the existence of a Φ-guaranteeing interface.We view the module and the external interface as players in a 2-player game. The interface has a winning strategy if it can guarantee that no matter what the module does, the overall specification Φ is met. The problem of incomplete specifications is resolved by allowing the interface to follow any strategy consistent with the interface specification. Our approach essentially combines traditional run-time monitoring and static analysis. This allows going beyond the focus of traditional run-time monitoring tools – error detection in the execution trace, towards the focus of the static analysis – bug detection in the programs.

SOFTARCH: TOOL SUPPORT FOR INTEGRATED SOFTWARE ARCHITECTURE DEVELOPMENT

A good software architecture design is crucial in successfully realising an object-oriented analysis (OOA) specification with an object-oriented design (OOD) model that meets the specification's functional and non-functional requirements. Most CASE tools and software architecture design notations do not adequately support software architecture modelling and analysis, integration with OOA and OOD methods and tools, and high-level, dynamic architectural visualisations of running systems. We describe SoftArch, an environment that provides flexible software architecture modelling using a concept of successive refinement and an extensible architecture meta-model. SoftArch provides extensible analysis tools enabling developers to analyse their architecture model properties. Run-time visualisation of systems uses dynamic annotation and animation of high-level architectural modelling views. SoftArch is integrated with a component-based CASE tool and run-time monitoring tool, and has facilities for 3rd party tool integration through a common exchange format. This paper discusses the motivation for SoftArch, its modelling, analysis and dynamic visualisation capabilities, and its integration with various analysis, design and implementation tools.

A goal-driven auto-configuration tool for the distributed workflow management system mentorlite

The Mentor-lite prototype has been developed within the research project “Architecture, Configuration, and Administration of Large Workflow Management Systems” funded by the German Science Foundation (DFG). It has evolved from its predecessor Mentor [1], but aims at a simpler architecture. The main goal of Mentor-lite has been to build a light-weight, extensible, and tailorable workflow management system (WFMS) with small footprint and easy-to-use administration capabilities. Our approach is to provide only kernel functionality inside the workflow engine, and consider system components like history management and worklist management as extensions on top of the kernel. The key point to retain the light-weight nature is that these extensions are implemented as workflows themselves. The workflow specifications are interpreted at runtime, which is a crucial prerequisite for flexible exception handling and dynamic modifications during runtime. The interpreter performs a stepwise execution of the workflow specification according to its formal semantics. For each step, the activities to be performed by the step are determined and started. Mentor-lite supports a protocol for distributed execution of workflows spread across multiple workflow engines. This support is crucial for workflows that span large, decentralized enterprises with largely autonomous organizational units or even cross multiple enterprises to form so-called “virtual enterprises”. A communication manager is responsible for sending and receiving synchronization messages between the engines. In order to guarantee a consistent global state even in the presence of site or network failures, we have built reliable message queues using the CORBA Object Transaction Services. For administration, Mentor-lite provides a Java-based workbench for workflow design, workflow partitioning across multiple workflow servers, and a Java-based runtime monitoring tool.