Improving efficiency and resilience in large-scale computing systems through analytics and data-driven management

Applications running in large-scale computing systems such as high performance computing (HPC) or cloud data centers are essential to many aspects of modern society, from weather forecasting to financial services. As the number and size of data centers increase with the growing computing demand, scalable and efficient management becomes crucial. However, data center management is a challenging task due to the complex interactions between applications, middleware, and hardware layers such as processors, network, and cooling units. This thesis claims that to improve robustness and efficiency of large-scale computing systems, significantly higher levels of automated support than what is available in today's systems are needed, and this automation should leverage the data continuously collected from various system layers. Towards this claim, we propose novel methodologies to automatically diagnose the root causes of performance and configuration problems and to improve efficiency through data-driven system management. We first propose a framework to diagnose software and hardware anomalies that cause undesired performance variations in large-scale computing systems. We show that by training machine learning models on resource usage and performance data collected from servers, our approach successfully diagnoses 98% of the injected anomalies at runtime in real-world HPC clusters with negligible computational overhead. We then introduce an analytics framework to address another major source of performance anomalies in cloud data centers: software misconfigurations. Our framework discovers and extracts configuration information from cloud instances such as containers or virtual machines. This is the first framework to provide comprehensive visibility into software configurations in multi-tenant cloud platforms, enabling systematic analysis for validating the correctness of software configurations. This thesis also contributes to the design of robust and efficient system management methods that leverage continuously monitored resource usage data. To improve performance under power constraints, we propose a workload- and cooling-aware power budgeting algorithm that distributes the available power among servers and cooling units in a data center, achieving up to 21% improvement in throughput per Watt compared to the state-of-the-art. Additionally, we design a network- and communication-aware HPC workload placement policy that reduces communication overhead by up to 30% in terms of hop-bytes compared to existing policies.2019-07-02T00:00:00

Task mapping on a dragonfly supercomputer

The dragonfly network topology has recently gained traction in the design of high performance computing (HPC) systems and has been implemented in large-scale supercomputers. The impact of task mapping, i.e., placement of MPI ranks onto compute cores, on the communication performance of applications on dragonfly networks has not been comprehensively investigated on real large-scale systems. This paper demonstrates that task mapping affects the communication overhead significantly in dragonflies and the magnitude of this effect is sensitive to the application, job size, and the OpenMP settings. Among the three task mapping algorithms we study (in-order, random, and recursive coordinate bisection), selecting a suitable task mapper reduces application communication time by up to 47%

Seeing into a Public Cloud: Monitoring the Massachusetts Open Cloud

Abstract Cloud users today have little visibility into the performance characteristics, power consumption, and utilization of cloud resources; and the cloud has little visibility into user application performance requirements and critical metrics such as response time and throughput. This paper outlines new efforts to reduce the information gap between the cloud users and the cloud. We first present a scalable monitoring platform to collect and retain rich information on a regional public cloud. Second, we present two motivating use cases that leverage the collected information: (1) Participation in emerging smart grid demand response programs in order to reduce datacenter energy costs and stabilize power grid demands, (2) budgeting available power to applications via peak shaving. This work is done in the context of the Massachusetts Open Cloud (MOC), a new public cloud project that has a central goal of enabling cloud research

Concepts of security from a perspective of political science

Security is one of the most basic needs of human beings and has become one of the fundamental issues not only for people but also for the states. Security has emerged within the human history and it is one of the fundamental concepts of the discipline of international relations. Many studies have been carried out into the concept of security in the discipline of international relations and many definitions of this concept have been offered in the conceptual and theoretical framework of these studies. However, in the literature there is no one, commonly accepted definition of security. Since security has a dynamic structure, the concept of security has also changed cyclically and maintained its existence. Unique opportunities for the concept of security emerged particularly during and after the cold war, arousing interest of many disciplines and theorists. The concept of security, which continues its existence today, has changed and deepened, confronted with different threats. In our study, firstly, the concept of security will be defined and its analysis will be performed by associating it with humanity and its history. Afterwards, it will be explained how the change in the system transformed the concept of security as conceived in terms of the critical theories developed in the cold war period and later

Primary Testicular Diffuse Large B-cell Lymphoma: A Rare Case Report

A 53-year-old male patient was admitted with a right testicular solid and painless mass at our clinic. A solid, irregular, 6×6 cm sized mass waspalpated on physical examination. Serum tumor markers were within normal range and a scrotal Doppler ultrasonography revealed a hypoechogenic,hypervascular, 69×35 mm sized mass on the right testis. No metastasis was found on the non-contrast-enhanced thoracoabdominal tomography.Right inguinal orchiectomy was performed. A diagnosis of testicular diffuse large B-cell lymphoma was made based on the pathological evaluation.The patient consulted with the hematology department and followed up. During the follow-up, no metastasis was observed

The severity of dissociative symptoms among patients with cannabis and synthetic cannabinoid use disorder: association with substance use characteristics and suicide

Background: Chanarin Dorfman Syndrome (CDS) is a rare autosomal recessive disorder characterized by the multisytemic accumulation of neutral lipids inside the cytoplasmic lipid droplets. This condition is caused by mutations in the abhydrolase domain containing 5 gene (ABHD5). In CDS the skin involvement is the prevalent and always observed clinical feature, consisting of a non-bullous congenital ichthyosiform erythroderma (NCIE). Moreover, a variable involvement of the liver and neuromuscular system can be also observed. In this report, we aimed to perform the clinical and genetic characterization of a patient affected by CDS with atypical dermatological findings, considering this rare inborn error of neutral lipid metabolism. Methods: Genomic DNA samples obtained from patient and his parents were used to perform the sequencing of the ABHD5 exons and their intron/exon boundaries. Bioinformatic analyses were performed to investigate the possible effect of the identified mutation on protein structure. Results: Here we present the case of a 29-year-old male patient with CDS, who, for long time, has been misdiagnosed as pityriasis rubra pilaris (PRP). He has a history of increasing hyperlipidemia; hepatomegaly associated with hepatosteatosis was also detected. ABHD5 molecular analysis revealed a novel missense mutation, the c.811G > A (p.G271R). Bioinformatic investigations showed that the variant has a deleterious effect on ABHD5 function, probably causing an incorrect folding of the mutant protein. Conclusions: These results highlihts the importance of genetic testing for ABHD5 in unresolved cases of patients presenting unusual skin lesions, that resemble PRP, associated with a history of hyperlipidemia and nonalcoholic fatty liver

Prevalence Of Alcohol Dependence And Abuse In A General Hospital; Sensitivity And Specificity Of Mast

Aim : Alcohol abuse and dependence is an important public health con-cern in most countries. It is also a big problem among the hospitalized patients. Method : This study was undertaken to determine the number of the patients with alcohol related problems in a general hospital sample, to compare the prevalence rate among clinics, to determine the sen-sitivity and specificity of MAST (Michigan Alcoholism Screening Test) for an inpatient sample. The data were collected from 13 inpatient clinics of Ankara Numune Research and Training Hospital. Result : A sample of 800 patients was enrolled in the study. 60 patients were (%7,5) diagnosed alcohol addiction and 11 were (%1,4) diagnosed as alcohol abuse. Alcohol addiction was most common in gastroenter-ology clinic. MAST sensitivity and specificity were found 0,74 and 0,98 respectively. Conclusion: MAST might be a useful instrument for screening alcohol related problems in a general hospital setting

Does tonsillectomy affect the outcome of drug treatment for the eradication of gastric H pylori infection? A pilot study

Eradication of Helicobacter pylori, which is associated with diverse gastroduodenal pathologies of varying severity, is sometimes challenging. We conducted a prospective study to determine the effect of tonsillectomy on the eradication of H pylon from the gastrointestinal tract. Our study population was made up of 46 patients-32 females and 14 males, aged 14 to 58 years (mean: 28.84 +/- 9.65)-who had chronic tonsillitis and concomitant dyspepsia. An initial gastrointestinal endoscopy was performed to obtain specimens for histology and a rapid urease test. These gastroscopies revealed that 32 patients were H pylon-positive (69.6%) and 14 were H pylori-negative (30.4%); these groups were designated A and B, respectively. The 32 H pylori-positive patients were divided into three subgroups based on the sequence in which they underwent drug therapy and tonsillectomy. All 3 subgroups received the same 14-day combination-drug regimen for eradication of gastric H pylori. The patients in group A1 (n = 12) underwent tonsillectomy prior to receiving drug treatment; 2 months after the cessation of drug therapy, they underwent a second gastroscopy. The patients in group A2 (n = 10) received drug treatment first followed by tonsillectomy; 2 months later, they underwent their second gastroscopy. The patients in group A3 (n = 10) received drug treatment first, then they underwent a second gastroscopy, and then they were taken for tonsillectomy. The success or failure of H pylori eradication was determined by the second gastroscopy. Also, analyses were performed after tonsillectomy to look for H pylori infection in tonsillar specimens. Eradication of gastric H pylori was achieved in 9 of the 12 group A1 patients (75.0%), 8 of the 10 group A2 patients (80.0%), and 7 of the 10 group A3 patients (70.0%); there were no statistically significant differences among the three groups. Likewise, there were no significant differences between any subgroups or combination of subgroups in terms of tonsillar positivity. As far as we know, this is the first study to investigate the effect of tonsillectomy on the outcome of H pylori eradication treatment. In light of our findings, we may speculate that tonsillar tissue does not seem to be a reservoir for H pylori infection. Although tonsillectomy had no significant effect on gastric H pylori eradication in our study, our results might have been skewed by the relatively small size of our sample

Leakage-Aware Cooling Management for Improving Server Energy Efficiency

The computational and cooling power demands of enterprise servers are increasing at an unsustainable rate. Understanding the relationship between computational power, temperature, leakage, and cooling power is crucial to enable energy-efficient operation at the server and data center levels. This paper develops empirical models to estimate the contributions of static and dynamic power consumption in enterprise servers for a wide range of workloads, and analyzes the interactions between temperature, leakage, and cooling power for various workload allocation policies. We propose a cooling management policy that minimizes the server energy consumption by setting the optimum fan speed during runtime. Our experimental results on a presently shipping enterprise server demonstrate that including leakage awareness in workload and cooling management provides additional energy savings without any impact on performance