@proceedings {47, title = {Understanding network failures in data centers: measurement, analysis, and implications}, year = {2011}, month = {01/2011}, pages = {350-361 }, publisher = {ACM}, abstract = {

We present the first large-scale analysis of failures in a data center network. Through our analysis, we seek to answer several fundamental questions: which devices/links are most unreliable, what causes failures, how do failures impact network traffic and how effective is network redundancy? We answer these questions using multiple data sources commonly collected by network operators. The key findings of our study are that (1) data center networks show high reliability, (2) commodity switches such as ToRs and AggS are highly reliable, (3) load balancers dominate in terms of failure occurrences with many short-lived software related faults,(4) failures have potential to cause loss of many small packets such as keep alive messages and ACKs, and (5) network redundancy is only 40\% effective in reducing the median impact of failure.

}, keywords = {Network Management, Network Services, Networks}, isbn = {978-1-4503-0797-0 }, doi = {10.1145/2018436.2018477 }, url = {http://dl.acm.org/citation.cfm?id=2018436.2018477\&coll=DL\&dl=ACM\&CFID=448744458\&CFTOKEN=88236964}, author = {Phillipa Gill and Navendu Jain and Nachiappan Nagappan} } @conference {66, title = {GreenFS: Making Enterprise Computers Greener by Protecting Them Better}, booktitle = {3rd ACM SIGOPS/EuroSys European Conference on Computer Systems 2008 (EuroSys {\textquoteright}08)}, year = {2008}, month = {04/2008}, publisher = {ACM}, organization = {ACM}, address = {Glasgow, Scotland}, abstract = {

Hard disks contain data - frequently an irreplaceable asset of high monetary and non-monetary value. At the same time, hard disks are mechanical devices that consume power, are noisy, and fragile when their platters are rotating.

In this paper we demonstrate that hard disks cause different kinds of problems for different types of computer systems and demystify several common misconceptions. We show that solutions developed to date are incapable of solving the power consumption, noise, and data reliability problems without sacrificing hard disk life-time, data reliability, or user convenience.

We considered data reliability, recovery, performance, user convenience, and hard disk-caused problems together at the enterprise scale. We have designed GreenFS: a fan-out stackable file system that offers all-time all-data run-time data protection, improves performance under typical user workloads, and allows hard disks to be kept off most of the time. As a result, GreenFS improves enterprise data protection, minimizes disk drive-related power consumption and noise and increases the chances of disk drive survivability in case of unexpected external impacts.

}, isbn = {978-1-60558-013-5}, url = {http://www.fsl.cs.stonybrook.edu/docs/greenfs/greenfs-eurosys08.pdf}, author = {Nikolai Joukov and Josef Sipek} }