Providing Consistent State to Distributed Storage System

In cloud storage systems, users must be able to shut down the application when not in use and restart it from the last consistent state when required. BlobSeer is a data storage application, specially designed for distributed systems, that was built as an alternative solution for the existing popular open-source storage system-Hadoop Distributed File System (HDFS). In a cloud model, all the components need to stop and restart from a consistent state when the user requires it. One of the limitations of BlobSeer DFS is the possibility of data loss when the system restarts. As such, it is important to provide a consistent start and stop state to BlobSeer components when used in a Cloud environment to prevent any data loss. In this paper, we investigate the possibility of BlobSeer providing a consistent state distributed data storage system with the integration of checkpointing restart functionality. To demonstrate the availability of a consistent state, we set up a cluster with multiple machines and deploy BlobSeer entities with checkpointing functionality on various machines. We consider uncoordinated checkpoint algorithms for their associated benefits over other alternatives while integrating the functionality to various BlobSeer components such as the Version Manager (VM) and the Data Provider. The experimental results show that with the integration of the checkpointing functionality, a consistent state can be ensured for a distributed storage system even when the system restarts, preventing any possible data loss after the system has encountered various system errors and failures

Hepatitis C (HCV) therapy for HCV mono-infected and HIV-HCV co-infected individuals living in Nepal.

BackgroundDespite direct-acting antivirals (DAA), aims to "eradicate" viral hepatitis by 2030 remain unlikely. In Nepal, an expert consortium was established to treat HCV through Nepal earthquakes aftermath offering a model for HCV treatment expansion in a resource-poor setting.Methodology/principal findingsIn 2015, we established a network of hepatologists, laboratory experts, and community-based leaders at 6 Opioid Substitution Treatment (OST) sites from 4 cities in Nepal screening 838 patients for a treatment cohort of 600 individuals with HCV infection and past or current drug use. During phase 1, patients were treated with interferon-based regimens (n = 46). During phase 2, 135 patients with optimal predictors (HIV controlled, without cirrhosis, low baseline HCV viral load) were treated with DAA-based regimens. During phase 3, IFN-free DAA treatment was expanded, regardless of HCV disease severity, HIV viremia or drug use. Sustained virologic response (SVR) was assessed at 12 weeks. Median age was 37 years and 95.5% were males. HCV genotype was 3 (53.2%) or 1a (40.7%) and 32% had cirrhosis; 42.5% were HIV-HCV coinfected. The intention-to-treat (ITT) SVR rates in phase 2 and 3 were 97% and 81%, respectively. The overall per-protocol and ITT SVR rates were 97% and 85%, respectively. By multivariable analysis, treatment at the Kathmandu site was protective and substance use, treatment during phase 3 were associated with failure to achieve SVR.Conclusions/significanceVery high SVR rates may be achieved in a difficult-to-treat, low-income population whatever the patient's profile and disease severity. The excellent treatment outcomes observed in this real-life community study should prompt further HCV treatment initiatives in Nepal