A Reliable and Cost-Efficient Auto-Scaling System for Web Applications Using Heterogeneous Spot Instances

Cloud providers sell their idle capacity on markets through an auction-like mechanism to increase their return on investment. The instances sold in this way are called spot instances. In spite that spot instances are usually 90% cheaper than on-demand instances, they can be terminated by provider when their bidding prices are lower than market prices. Thus, they are largely used to provision fault-tolerant applications only. In this paper, we explore how to utilize spot instances to provision web applications, which are usually considered availability-critical. The idea is to take advantage of differences in price among various types of spot instances to reach both high availability and significant cost saving. We first propose a fault-tolerant model for web applications provisioned by spot instances. Based on that, we devise novel auto-scaling polices for hourly billed cloud markets. We implemented the proposed model and policies both on a simulation testbed for repeatable validation and Amazon EC2. The experiments on the simulation testbed and the real platform against the benchmarks show that the proposed approach can greatly reduce resource cost and still achieve satisfactory Quality of Service (QoS) in terms of response time and availability

Scaling Virtualized Smartphone Images in the Cloud

Üks selle Bakalaureuse töö eesmärkidest oli Android-x86 nutitelefoni platvormi juurutamine pilvekeskkonda ja välja selgitamine, kas valitud instance on piisav virtualiseeritud nutitelefoni platvormi juurutamiseks ning kui palju koormust see talub. Töös kasutati Amazoni instance'i M1 Small, mis oli piisav, et juurutada Androidi virtualiseeritud platvormi, kuid jäi kesisemaks kui mobiiltelefon, millel teste läbi viidi. M1 Medium instance'i tüüp oli sobivam ja näitas paremaid tulemusi võrreldes telefoniga. Teostati koormusteste selleks vastava tööriistaga Tsung, et näha, kui palju üheaegseid kasutajaid instance talub. Testi läbiviimiseks paigaldasime Dalviku instance'ile Tomcat serveri. Pärast teste ühe eksemplariga, juurutasime külge Elastic Load Balancing ja automaatse skaleerimise Amazon Auto Scaling tööriista. Esimene neist jaotas koormust instance'ide vahel. Automaatse skaleerimise tööriista kasutasime, et rakendada horisontaalset skaleerimist meie Android-x86 instance'le. Kui CPU tõusis üle 60% kauemaks kui üks minut, siis tehti eelmisele identne instance ja koormust saadeti edaspidi sinna. Seda protseduuri vajadusel korrati maksimum kümne instance'ini. Meie teostusel olid tagasilöögid, sest Elastic Load Balancer aegus 60 sekundi pärast ning me ei saanud kõikide välja saadetud päringutele vastuseid. Serverisse saadetud faili kirjutamine ja kompileerimine olid kulukad tegevused ja seega ei lõppenud kõik 60 sekundi jooksul. Me ei saanud koos Load Balancer'iga läbiviidud testidest piisavalt andmeid, et teha järeldusi, kas virtualiseeritud nutitelefoni platvorm Android on hästi või halvasti skaleeruv.In this thesis we deployed a smartphone image in an Amazon EC2 instance and ran stress tests on them to know how much users can one instance bear and how scalable it is. We tested how much time would a method run in a physical Android device and in a cloud instance. We deployed CyanogenMod and Dalvik for a single instance. We used Tsung for stress testing. For those tests we also made a Tomcat server on Dalvik instance that would take the incoming file, the file would be compiled with java and its class file would be wrapped into dex, a Dalvik executable file, that is later executed with Dalvik. Three instances made a Tsung cluster that sent load to a Dalvik Virtual Machine instance. For scaling we used Amazon Auto Scaling tool and Elastic Load Balancer that divided incoming load between the instances

ALOJA: A framework for benchmarking and predictive analytics in Hadoop deployments

This article presents the ALOJA project and its analytics tools, which leverages machine learning to interpret Big Data benchmark performance data and tuning. ALOJA is part of a long-term collaboration between BSC and Microsoft to automate the characterization of cost-effectiveness on Big Data deployments, currently focusing on Hadoop. Hadoop presents a complex run-time environment, where costs and performance depend on a large number of configuration choices. The ALOJA project has created an open, vendor-neutral repository, featuring over 40,000 Hadoop job executions and their performance details. The repository is accompanied by a test-bed and tools to deploy and evaluate the cost-effectiveness of different hardware configurations, parameters and Cloud services. Despite early success within ALOJA, a comprehensive study requires automation of modeling procedures to allow an analysis of large and resource-constrained search spaces. The predictive analytics extension, ALOJA-ML, provides an automated system allowing knowledge discovery by modeling environments from observed executions. The resulting models can forecast execution behaviors, predicting execution times for new configurations and hardware choices. That also enables model-based anomaly detection or efficient benchmark guidance by prioritizing executions. In addition, the community can benefit from ALOJA data-sets and framework to improve the design and deployment of Big Data applications.This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 639595). This work is partially supported by the Ministry of Economy of Spain under contracts TIN2012-34557 and 2014SGR1051.Peer ReviewedPostprint (published version

Performance-oriented Cloud Provisioning: Taxonomy and Survey

Cloud computing is being viewed as the technology of today and the future. Through this paradigm, the customers gain access to shared computing resources located in remote data centers that are hosted by cloud providers (CP). This technology allows for provisioning of various resources such as virtual machines (VM), physical machines, processors, memory, network, storage and software as per the needs of customers. Application providers (AP), who are customers of the CP, deploy applications on the cloud infrastructure and then these applications are used by the end-users. To meet the fluctuating application workload demands, dynamic provisioning is essential and this article provides a detailed literature survey of dynamic provisioning within cloud systems with focus on application performance. The well-known types of provisioning and the associated problems are clearly and pictorially explained and the provisioning terminology is clarified. A very detailed and general cloud provisioning classification is presented, which views provisioning from different perspectives, aiding in understanding the process inside-out. Cloud dynamic provisioning is explained by considering resources, stakeholders, techniques, technologies, algorithms, problems, goals and more.Comment: 14 pages, 3 figures, 3 table

Optimal Resource Provisioning for Workflows in Cloud

Pilvearvutuse populaarsus on viimaste aastate jooksul märkmisväärselt kasvanud. Kasutades teenustele orienteeritud arhitektuure ning virtualiseerimist, võimaldab pilv varieeruva koormusega skaleerumist eelkõige ettevõtetele suunatud programmidele. See on üks suuremaid põhjuseid miks töövoogusid pilve migreeritakse. Kuna iga töövoo osa vajab vastavalt kas rohkem või vähem ressursse, siis pilve poolt pakutud ressurssid peavad skaleeruma nii, et see ühtiks töövoo vajadustega. Resursside skaleerimist saab teha manuaalselt, eeldades et töökoormuse muutusperioodid on deterministlikud, või automaatselt, kui töövoos esineb ettearvamatuid koormuse tõuse ning langusi. Seni on esitatud mitmeid automaatse skaleerumise ideid. Mõned neist meetoditest proovivad ennustada, kui palju koormust võib esineda, samal ajal kui teised meetodid proovivad ressursse pakkuda alles koormuse kohale jõudmise ajal. Mõlema meetodi puhul leidub aga vajadus strateegia järgi, mis tagaks, et ressursse varustataks optimaalselt ehk tuvastada, kui mitu serverit tuleb lisada või eemaldada süsteemist, et rahuldada koormuse nõudlus ning samal ajal minimiseerida ka kulu. Antud magistritöös esitatakse lineaaprogrammeerimisel põhinev meetod, mis arvestab peamisi tegureid skaleerimises nagu, kulu, konfiguratsiooni hind, masinate jõudlus, pilve mahtuvus ning ka iga töömasina kestvus. Antud andmete põhjal tagastatakse optimaalne kombinatsioon võimalikest instantsitüüpidest mis rahuldaks igat töövoo alamosa kõige paremini. Lisaks loodi ka simulatsioon antud mudeli testimiseks ning katsete jooksutamiseks. Tulemuste kohaselt on näha, et pakutud meetod vähendab töövoogude jooksutamise hinda pilves.Cloud computing has gained significant popularity over past few years. Employing service-oriented architecture and resource virtualization technology, cloud provides the highest level of scalability for enterprise applications with variant load. This feature of cloud is the main attraction for migration of workflows to the cloud. Since each task of a workflow requires different processing power to perform its operation, at time of load variation it must scale in a manner fulfilling its specific requirements the most. Scaling can be done manually, provided that the load change periods are deterministic, or automatically, when there are unpredicted load spikes and slopes in the workload. A number of auto-scaling policies have been proposed so far. Some of these methods try to predict next incoming loads, while others tend to react to the incoming load at its arrival time and change the resource setup based on the real load rate rather than predicted one. However, in both methods there is need for an optimal resource provisioning policy that determines how many servers must be added to or removed from the system in order to fulfill the load while minimizing the cost. Current methods in this field take into account several of related parameters such as incoming workload, CPU usage of servers, network bandwidth, response time, processing power and cost of the servers. Nevertheless, none of them incorporates the life duration of a running server, the metric that can contribute to finding the most optimal policy. This parameter finds importance when the scaling algorithm tries to optimize the cost with employing a spectrum of various instance types featuring different processing powers and costs. In this paper, we will propose a generic LP(linear programming) model that takes into account all major factors involved in scaling including periodic cost, configuration cost and processing power of each instance type, instance count limit of clouds, and also life duration of each instance with customizable level of precision, and outputs an optimal combination of possible instance types suiting each task of a workflow the most. We created a simulation tool based on the proposed model and used 24-hour workload of ClarkNet ISP to conduct performance experiments. The results of experiments suggest that our optimal policy can minimize the cost of running a workflow in the cloud