742 research outputs found
Tachyon: Reliable, Memory Speed Storage for Cluster Computing Frameworks
Tachyon is a distributed file system enabling reliable data sharing at memory speed across cluster computing frameworks. While caching today improves read workloads, writes are either network or disk bound, as replication is used for fault-tolerance. Tachyon eliminates this bottleneck by pushing lineage, a well-known technique, into the storage layer. The key challenge in making a long-running lineage-based storage system is timely data recovery in case of failures. Tachyon addresses this issue by introducing a checkpointing algorithm that guarantees bounded recovery cost and resource allocation strategies for recomputation under commonly used resource schedulers. Our evaluation shows that Tachyon outperforms in-memory HDFS by 110x for writes. It also improves the end-to-end latency of a realistic workflow by 4x. Tachyon is open source and is deployed at multiple companies.National Science Foundation (U.S.) (CISE Expeditions Award CCF-1139158)Lawrence Berkeley National Laboratory (Award 7076018)United States. Defense Advanced Research Projects Agency (XData Award FA8750-12-2-0331
An Intermediate Data-driven Methodology for Scientific Workflow Management System to Support Reusability
Automatic processing of different logical sub-tasks by a set of rules is a workflow. A workflow management system (WfMS) is a system that helps us accomplish a complex scientific task through making a sequential arrangement of sub-tasks available as tools. Workflows are formed with modules from various domains in a WfMS, and many collaborators of the domains are involved in the workflow design process. Workflow Management Systems (WfMSs) have been gained popularity in recent years for managing various tools in a system and ensuring dependencies while building a sequence of executions for scientific analyses. As a result of heterogeneous tools involvement and collaboration requirement, Collaborative Scientific Workflow Management Systems (CSWfMS) have gained significant interest in the scientific analysis community. In such systems, big data explosion issues exist with massive velocity and variety characteristics for the heterogeneous large amount of data from different domains. Therefore a large amount of heterogeneous data need to be managed in a Scientific Workflow Management System (SWfMS) with a proper decision mechanism. Although a number of studies addressed the cost management of data, none of the existing studies are related to real- time decision mechanism or reusability mechanism. Besides, frequent execution of workflows in a SWfMS generates a massive amount of data and characteristics of such data are always incremental. Input data or module outcomes of a workflow in a SWfMS are usually large in size. Processing of such data-intensive workflows is usually time-consuming where modules are computationally expensive for their respective inputs. Besides, lack of data reusability, limitation of error recovery, inefficient workflow processing, inefficient storing of derived data, lacking in metadata association and lacking in validation of the effectiveness of a technique of existing systems need to be addressed in a SWfMS for efficient workflow building by maintaining the big data explosion.
To address the issues, in this thesis first we propose an intermediate data management scheme for a SWfMS. In our second attempt, we explored the possibilities and introduced an automatic recommendation technique for a SWfMS from real-world workflow data (i.e Galaxy [1] workflows) where our investigations show that the proposed technique can facilitate 51% of workflow building in a SWfMS by reusing intermediate data of previous workflows and can reduce 74% execution time of workflow buildings in a SWfMS. Later we propose an adaptive version of our technique by considering the states of tools in a SWfMS, which shows around 40% reusability for workflows. Consequently, in our fourth study, We have done several experiments for analyzing the performance and exploring the effectiveness of the technique in a SWfMS for various environments.
The technique is introduced to emphasize on storing cost reduction, increase data reusability, and faster workflow execution, to the best of our knowledge, which is the first of its kind. Detail architecture and evaluation of the technique are presented in this thesis. We believe our findings and developed system will contribute significantly to the research domain of SWfMSs
Secure Time-Aware Provenance for Distributed Systems
Operators of distributed systems often find themselves needing to answer forensic questions, to perform a variety of managerial tasks including fault detection, system debugging, accountability enforcement, and attack analysis. In this dissertation, we present Secure Time-Aware Provenance (STAP), a novel approach that provides the fundamental functionality required to answer such forensic questions – the capability to “explain” the existence (or change) of a certain distributed system state at a given time in a potentially adversarial environment.
This dissertation makes the following contributions. First, we propose the STAP model, to explicitly represent time and state changes. The STAP model allows consistent and complete explanations of system state (and changes) in dynamic environments. Second, we show that it is both possible and practical to efficiently and scalably maintain and query provenance in a distributed fashion, where provenance maintenance and querying are modeled as recursive continuous queries over distributed relations. Third, we present security extensions that allow operators to reliably query provenance information in adversarial environments. Our extensions incorporate tamper-evident properties that guarantee eventual detection of compromised nodes that lie or falsely implicate correct nodes. Finally, the proposed research results in a proof-of-concept prototype, which includes a declarative query language for specifying a range of useful provenance queries, an interactive exploration tool, and a distributed provenance engine for operators to conduct analysis of their distributed systems. We discuss the applicability of this tool in several use cases, including Internet routing, overlay routing, and cloud data processing
Workflow Provenance: from Modeling to Reporting
Workflow provenance is a crucial part of a workflow system as it enables data lineage analysis, error tracking, workflow monitoring, usage pattern discovery, and so on. Integrating provenance into a workflow system or modifying a workflow system to capture or analyze different provenance information is burdensome, requiring extensive development because provenance mechanisms rely heavily on the modelling, architecture, and design of the workflow system. Various tools and technologies exist for logging events in a software system. Unfortunately, logging tools and technologies are not designed for capturing and analyzing provenance information. Workflow provenance is not only about logging, but also about retrieving workflow related information from logs. In this work, we propose a taxonomy of provenance questions and guided by these questions, we created a workflow programming model 'ProvMod' with a supporting run-time library to provide automated provenance and log analysis for any workflow system. The design and provenance mechanism of ProvMod is based on recommendations from prominent research and is easy to integrate into any workflow system. ProvMod offers Neo4j graph database support to manage semi-structured heterogeneous JSON logs. The log structure is adaptable to any NoSQL technology. For each provenance question in our taxonomy, ProvMod provides the answer with data visualization using Neo4j and the ELK Stack. Besides analyzing performance from various angles, we demonstrate the ease of integration by integrating ProvMod with Apache Taverna and evaluate ProvMod usability by engaging users. Finally, we present two Software Engineering research cases (clone detection and architecture extraction) where our proposed model ProvMod and provenance questions taxonomy can be applied to discover meaningful insights
Simplifying Internet of Things (IoT) Data Processing Work ow Composition and Orchestration in Edge and Cloud Datacenters
Ph. D. Thesis.Internet of Things (IoT) allows the creation of virtually in nite connections into a
global array of distributed intelligence. Identifying a suitable con guration of devices,
software and infrastructures in the context of user requirements are fundamental to
the success of delivering IoT applications. However, the design, development, and
deployment of IoT applications are complex and complicated due to various unwarranted
challenges. For instance, addressing the IoT application users' subjective and
objective opinions with IoT work
ow instances remains a challenge for the design of
a more holistic approach. Moreover, the complexity of IoT applications increased exponentially
due to the heterogeneous nature of the Edge/Cloud services, utilised to
lower latency in data transformation and increase reusability.
To address the composition and orchestration of IoT applications in the cloud and
edge environments, this thesis presents IoT-CANE (Context Aware Recommendation
System) as a high-level uni ed IoT resource con guration recommendation system
which embodies a uni ed conceptual model capturing con guration, constraint and
infrastructure features of Edge/Cloud together with IoT devices. Second, I present
an IoT work
ow composition system (IoTWC) to allow IoT users to pipeline their
work
ows with proposed IoT work
ow activity abstract patterns. IoTWC leverages
the analytic hierarchy process (AHP) to compose the multi-level IoT work
ow that
satis es the requirements of any IoT application. Besides, the users are be tted with
recommended IoT work
ow con gurations using an AHP based multi-level composition
framework. The proposed IoTWC is validated on a user case study to evaluate
the coverage of IoT work
ow activity abstract patterns and a real-world scenario for
smart buildings. Last, I propose a fault-tolerant automation deployment IoT framework
which captures the IoT work
ow plan from IoTWC to deploy in multi-cloud
edge environment with a fault-tolerance mechanism. The e ciency and e ectiveness
of the proposed fault-tolerant system are evaluated in a real-time water
ooding data
monitoring and management applicatio
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