Performance variability has been acknowledged as a problem for over a decade by cloud practitioners and performance engineers. Yet, our survey of top systems conferences reveals that the research community regularly disregards variability when running experiments in the cloud. Focusing on networks, we assess the impact of variability on cloud-based big-data workloads by gathering traces from mainstream commercial clouds and private research clouds. Our data collection consists of millions of datapoints gathered while transferring over 9 petabytes of data. We characterize the network variability present in our data and show that, even though commercial cloud providers implement mechanisms for quality-of-service enforcement, variability still occurs, and is even exacerbated by such mechanisms and service provider policies. We show how big-data workloads suffer from significant slowdowns and lack predictability and replicability, even when state-of-the-art experimentation techniques are used. We provide guidelines for practitioners to reduce the volatility of big data performance, making experiments more repeatable.
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SECProv: Trustworthy and Efficient Provenance Management in the Cloud.
The black-box nature of clouds introduces a lack of trusts in clouds. Since provenance can provide a complete history of an entity, trustworthy provenance management for data, application, or workflow can make the cloud more account- able. Current research on cloud provenance mainly focuses on collecting provenance records and trusting the cloud providers in managing the provenance records. However, a dishonest cloud provider can alter the provenance records, as the records are stored within the control of the cloud provider. To solve this problem, we first propose CloProv – a provenance model to capture the complete provenance of any type of entities in the cloud. We analyze the threats on the CloProv model considering collusion among malicious users and dishonest cloud providers. Based on the threat model, we propose a secure data provenance scheme – SECProv for cloud-based, multi-user, shared data storage systems. We integrate SECProv with the object storage module of an open source cloud framework – OpenStack Swift and analyze the efficiency of the proposed scheme.
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- PAR ID:
- 10077219
- Date Published:
- Journal Name:
- Proceedings - IEEE INFOCOM
- ISSN:
- 0743-166X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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