@conference {19489,
	title = {Cloud software upgrades: Challenges and opportunities},
	booktitle = {2011 International Workshop on the Maintenance and Evolution of Service-Oriented and Cloud-Based Systems (MESOCA) },
	year = {2011},
	month = {2011///},
	pages = {1 - 10},
	abstract = {The fast evolution pace for cloud computing software is on a collision course with our growing reliance on cloud computing. On one hand, cloud software must have the agility to evolve rapidly, in order to remain competitive; on the other hand, more and more critical services become dependent on the cloud and demand high availability through firm Service Level Agreements (SLAs) for cloud infrastructures. This race between the needs to increase both the cloud upgrade frequency and the service availability is unsustainable. In this paper we highlight challenges and opportunities for upgrades in the cloud. We survey the release histories of several cloud applications to analyze their evolution pace, and we discuss the shortcomings with current cloud upgrade mechanisms. We outline several solutions for sustaining this evolution while improving availability, by focusing on the novel characteristics of cloud computing. By discussing several promising directions for realizing this vision, we propose a research agenda for the future of software upgrades in the cloud.},
	keywords = {Availability, Cloud computing, cloud computing software, cloud upgrade frequency, collision course, Electronic publishing, Encyclopedias, service level agreement, service-oriented architecture},
	author = {Neamtiu, I. and Tudor Dumitras}
}
@article {14690,
	title = {Evaluating Dynamic Software Update Safety Using Systematic Testing},
	journal = {IEEE Transactions on Software Engineering},
	volume = {PP},
	year = {2011},
	pages = {1 - 1},
	abstract = {Dynamic software updating (DSU) systems patch programs on the fly without incurring downtime. To avoid failures due to the updating process itself, many DSU systems employ timing restrictions. However, timing restrictions are theoretically imperfect, and their practical effectiveness is an open question. This paper presents the first significant empirical evaluation of three popular timing restrictions: activeness safety (AS), which prevents updates to active functions; con-freeness safety (CFS), which only allows modifications to active functions when doing so is provably type-safe; and manual identification of the event-handling loops during which an update may occur. We evaluated these timing restrictions using a series of DSU patches to three programs: OpenSSH, vsftpd, and ngIRCd. We systematically applied updates at each distinct update point reached during execution of a suite of system tests for these programs to determine which updates pass and which fail. We found that all three timing restrictions prevented most failures, but only manual identification allowed none. Further, although CFS and AS allowed many more update points, manual identification still supported updates with minimal delay. Finally, we found that manual identification required the least developer effort. Overall, we conclude that manual identification is most effective.},
	keywords = {and serviceability, Availability, Computer Systems Organization, Delay, Manuals, Performance of Systems, reliability, Safety, servers, software, software engineering, Test execution, Testing and Debugging},
	isbn = {0098-5589},
	doi = {10.1109/TSE.2011.101},
	author = {Hayden,C. and Smith,E. and Hardisty,E. and Hicks, Michael W. and Foster, Jeffrey S.}
}
@conference {18556,
	title = {Circumventing censorship with collage},
	booktitle = {Proceedings of the ACM SIGCOMM 2010 conference},
	series = {SIGCOMM {\textquoteright}10},
	year = {2010},
	month = {2010///},
	pages = {471 - 472},
	publisher = {ACM},
	organization = {ACM},
	address = {New York, NY, USA},
	abstract = {Oppressive regimes and even democratic governments restrict Internet access. Existing anti-censorship systems often require users to connect through proxies, but these systems are relatively easy for a censor to discover and block. We explore a possible next step in the censorship arms race: rather than relying on a single system or set of proxies to circumvent censorship firewalls, we use the vast deployment of sites that host user-generated content to breach these firewalls. We have developed Collage, which allows users to exchange messages through hidden channels in sites that host user-generated content. To send a message, a user embeds it into cover traffic and posts the content on some site, where receivers retrieve this content. Collage makes it difficult for a censor to monitor or block these messages by exploiting the sheer number of sites where users can exchange messages and the variety of ways that a message can be hidden. We have built a censorship-resistant news reader using Collage that can retrieve from behind a censorship firewall and show Collage{\textquoteright}s effectiveness with a live demonstration of its complete infrastructure.},
	keywords = {Availability, censorship},
	isbn = {978-1-4503-0201-2},
	doi = {10.1145/1851182.1851269},
	url = {http://doi.acm.org/10.1145/1851182.1851269},
	author = {Burnett,Sam and Feamster, Nick and Vempala,Santosh}
}
@conference {17535,
	title = {Predicting the CPU availability of time-shared Unix systems on the computational grid},
	booktitle = {The Eighth International Symposium on High Performance Distributed Computing, 1999. Proceedings},
	year = {1999},
	month = {1999///},
	pages = {105 - 112},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Focuses on the problem of making short- and medium-term forecasts of CPU availability on time-shared Unix systems. We evaluate the accuracy with which availability can be measured using the Unix load average, the Unix utility {\textquotedblleft}vmstat{\textquotedblright} and the Network Weather Service (NWS) CPU sensor that uses both. We also examine the autocorrelation between successive CPU measurements to determine their degree of self-similarity. While our observations show a long-range autocorrelation dependence, we demonstrate how this dependence manifests itself in the short- and medium-term predictability of the CPU resources in our study},
	keywords = {accuracy, Application software, Autocorrelation, Availability, Central Processing Unit, computational grid, correlation methods, CPU availability prediction, CPU resources predictability, CPU sensor, Dynamic scheduling, grid computing, Load forecasting, long-range autocorrelation dependence, medium-term forecasts, network operating systems, Network Weather Service, NWS, performance evaluation, self-similarity degree, short-term forecasts, successive CPU measurements, Time measurement, Time sharing computer systems, time-shared Unix systems, time-sharing systems, Unix, Unix load average, vmstat utility, Weather forecasting},
	isbn = {0-7803-5681-0},
	doi = {10.1109/HPDC.1999.805288},
	author = {Wolski,R. and Spring, Neil and Hayes,J.}
}
@article {11931,
	title = {Distributed Checkpointing for Globally Consistent States of Databases},
	journal = {IEEE Trans. Softw. Eng.},
	volume = {15},
	year = {1989},
	month = {1989/10//},
	pages = {1157 - 1167},
	keywords = {Availability, checkpoint, consistency, distributed database, noninterference, recovery, transaction},
	isbn = {0098-5589},
	doi = {10.1109/TSE.1989.559763},
	url = {http://dx.doi.org/10.1109/TSE.1989.559763},
	author = {Son,Sang Hyuk and Agrawala, Ashok K.}
}
