PIASA: A power and interference aware resource management strategy for heterogeneous workloads in cloud data centers

Cloud data centers have been progressively adopted in different scenarios, as reflected in the execution of heterogeneous applications with diverse workloads and diverse quality of service (QoS) requirements. Virtual machine (VM) technology eases resource management in physical servers and helps cloud providers achieve goals such as optimization of energy consumption. However, the performance of an application running inside a VM is not guaranteed due to the interference among co-hosted workloads sharing the same physical resources. Moreover, the different types of co-hosted applications with diverse QoS requirements as well as the dynamic behavior of the cloud makes efficient provisioning of resources even more difficult and a challenging problem in cloud data centers. In this paper, we address the problem of resource allocation within a data center that runs different types of application workloads, particularly CPU- and network-intensive applications. To address these challenges, we propose an interference- and power-aware management mechanism that combines a performance deviation estimator and a scheduling algorithm to guide the resource allocation in virtualized environments. We conduct simulations by injecting synthetic workloads whose characteristics follow the last version of the Google Cloud tracelogs. The results indicate that our performance-enforcing strategy is able to fulfill contracted SLAs of real-world environments while reducing energy costs by as much as 21%

A Study on Cloud Cost Efficiency by Exploiting Idle Billing Period Fractions

In most of the current commercial Clouds, resources are billed based on a time interval equal to one hour, as is the case of virtual machine (VM) instances on Amazon EC2. Such time interval is usually long, and yet the user has to pay for the whole last hour, even if he/she has only used a fraction of it, contradicting the pay-as-you-go model of Clouds. In this paper, we analyse the advantages of adopting alternative scheduling policies that exploit idle last time intervals, in terms of service cost to Cloud users and operating costs to Cloud providers. Using a real-life astronomy workflow application, constrained by user-defined Deadline and Budget quality of service (QoS) parameters, a set of online state-ofthe- art-based scheduling algorithms try different execution and resource provisioning plans. Our results show that exploitation of partially idle last time intervals can reduce the cost of service to the end user, and augments providers competitiveness up to 21.6% through energy efficiency improvement and consequent lowering of operational costs.info:eu-repo/semantics/publishedVersio

Constructing Reliable Computing Environments on Top of Amazon EC2 Spot Instances

Cloud provider Amazon Elastic Compute Cloud (EC2) gives access to resources in the form of virtual servers, also known as instances. EC2 spot instances (SIs) offer spare computational capacity at steep discounts compared to reliable and fixed price on-demand instances. The drawback, however, is that the delay in acquiring spots can be incredible high. Moreover, SIs may not always be available as they can be reclaimed by EC2 at any given time, with a two-minute interruption notice. In this paper, we propose a multi-workflow scheduling algorithm, allied with a container migration-based mechanism, to dynamically construct and readjust virtual clusters on top of non-reserved EC2 pricing model instances. Our solution leverages recent findings on performance and behavior characteristics of EC2 spots. We conducted simulations by submitting real-life workflow applications, constrained by user-defined deadline and budget quality of service (QoS) parameters. The results indicate that our solution improves the rate of completed tasks by almost 20%, and the rate of completed workflows by at least 30%, compared with other state-of-the-art algorithms, for a worse-case scenario

Perfil epidemiológico de mulheres com vaginose bacteriana, atendidas em um ambulatório de doenças sexualmente transmissíveis, em São Paulo, SP Epidemiological profile of women with bacterial vaginosis treated at a clinic for sexually transmitted diseases in the city of Sao Paulo, SP

FUNDAMENTOS - A vaginose bacteriana é doença de grande relevância devido à sua alta prevalência e suas complicações obstétricas e ginecológicas. OBJETIVO - Descrever o perfil epidemiológico das pacientes com diagnóstico de vaginose bacteriana, atendidas em um ambulatório de São Paulo, segundo variáveis de interesse social, demográfico e clínico. MÉTODOS - Estudo transversal descritivo, baseado nos prontuários de 658 mulheres atendidas de janeiro de 1999 a dezembro de 2004. Foram coletadas as seguintes informações: idade, cor, estado civil, procedência, grau de escolaridade, preferência sexual, número de parceiros e presença de doença sexualmente transmissível associada. RESULTADOS - A prevalência encontrada foi de 29%. Com relação ao perfil da mulher com vaginose bacteriana, observou-se maior ocorrência em jovens entre 10 e 19 anos (40%), negras (37,1%), viúvas (62,5%), com segundo grau incompleto (39,5%), heterossexuais (29,5%), com dois ou mais parceiros sexuais nos últimos 30 dias (50%) e nos últimos cinco anos (32,3%). A associação com outras doenças sexualmente transmissíveis, concomitante, foi encontrada em 31,9% dos casos. CONCLUSÃO - A distribuição dos casos segundo faixa etária, raça, número de parceiros sexuais e associação com outras doenças encontradas nas pacientes com diagnóstico de vaginose bacteriana foi semelhante aos dados encontrados na literatura. A ocorrência está dentro dos limites descritos (10 e 36%).<br>BACKGROUND- Bacterial vaginosis is an important disease on account of its high prevalence as well as the obstetrical and gynecological complications. OBJECTIVE- To present an epidemiological profile of patients diagnosed with bacterial vaginosis seen at an outpatient clinic in the city of Sao Paulo, Brazil, described according to socio-demographic and clinical variables. METHODS- A cross-sectional descriptive study was performed by collecting data from the medical records of 658 females, seen from January, 1999 to December, 2004. Our study took into account age, ethnicity, marital status, schooling, sexual preference, number of partners and associated sexual diseases. RESULTS- The prevalence observed was 29%. Regarding the profile of women with bacterial vaginosis, the highest ratio of cases occurred in adolescents aged 10 to 19 years old (40%), black women (37.1%), widows (62.5%), women who have not graduated from high school (39.5%), heterosexual women (29.5%), women with two or more sexual partners in the last 30 days (50%) and in the last five years (35.3%). The concomitant association with other sexually transmitted diseases was found in 35% of cases. CONCLUSION- The distribution of bacterial vaginosis in patients according to age, ethnicity, number of sexual partners and associated sexual diseases was similar to that described in the literature. The observed ratio was within values of other studies (10 to 36%)