DEFT: Distributed, Elastic, and Fault-tolerant State Management of Network Functions

Network function virtualization is the key to developing elastically scalable and fault-tolerant network functions (e.g. load balancer, firewall etc.). By integrating NFV and SDN technologies, it is feasible to dynamically reroute traffic to new network function (NF) instances in the event of an NF failure or overload scenario. The fact that the majority of network functions are stateful makes the task more challenging. State migration and state replication are common approaches in achieving elasticity and fault tolerance. The majority of the studies in the literature either emphasize fault tolerance or elastic scalability while designing a state management system for network functions. In this paper, we have designed a complete state management system, called DEFT, that meets both elasticity and fault-tolerance goals. Our system also supports strong consistency on global state updates. While existing designs rely on a central controller or remote central storage to achieve strong consistency on state updates, DEFT utilizes distributed consensus mechanism to achieve the same. We have done a proof of concept implementation of DEFT and extensively tested DEFT under several model conditions to evaluate its scalability and performance. Our experimental results show that DEFT is scalable and maintains a considerably high throughput throughout. It incurs minimal performance overhead while achieving strong consistency on state updates

Linkage mapping of a complex trait in the New York population of the GAW14 simulated dataset: a multivariate phenotype approach

Multivariate phenotypes underlie complex traits. Thus, instead of using the end-point trait, it may be statistically more powerful to use a multivariate phenotype correlated to the end-point trait for detecting linkage. In this study, we develop a reverse regression method to analyze linkage of Kofendrerd Personality Disorder affection status in the New York population of the Genetic Analysis Workshop 14 (GAW14) simulated dataset. When we used the multivariate phenotype, we obtained significant evidence of linkage near four of the six putative loci in at least 25% of the replicates. On the other hand, the linkage analysis based on Kofendrerd Personality Disorder status as a phenotype produced significant findings only near two of the loci and in a smaller proportion of replicates

De sanctis-cacchione syndrome with subdural effusion: A rare case from india with review of literature

De Sanctis-Cacchione syndrome (DCS) formerly known as xerodermic idiocy is characterised by cutaneous photosensitivity, microcephaly, mental retardation, short stature, hypogonadism, spasticity, peripheral neuropathy and sensorineural deafness. Here in, we present the case of a four and half years old male child with features of severe acute malnutrition (SAM) with a typical bird like facies and sunken eyes who had history of photosensitive pruritic pigmentary skin lesions on sun exposed areas from a very early age of six months. Gross developmental delay, ataxia, microcephaly, short stature, hypogonadism and cachectic wasting were identified on examination and hypertransaminasemia and hypothyroidism were recorded from biochemical profile. Subsequent visual evoked response and brainstem evoked response audiometry revealed anterior visual pathway dysfunction and bilateral profound sensorineural hearing loss. Magnetic resonance imaging of brain yielded subdural effusion with mass effect in addition to cerebro-cerebral atrophy and demyelination. Skin biopsy further detected dysplastic changes and early signs of squamous cell carcinoma (SCC). Although few cases are reported sporadically throughout the world, to our best of knowledge till date only 11 such cases have been reported completely in Indian medical literature which makes our case report the 12th one with distinctive novel association of subdural effusion

Surface Stoichiometry and Depth Profile of Tix-CuyNz Thin Films Deposited by Magnetron Sputtering

We report the surface stoichiometry of Tix-CuyNz thin film as a function of film depth. Films are deposited by high power impulse (HiPIMS) and DC magnetron sputtering (DCMS). The composition of Ti, Cu, and N in the deposited film is investigated by X-ray photoelectron spectroscopy (XPS). At a larger depth, the relative composition of Cu and Ti in the film is increased compared to the surface. The amount of adventitious carbon which is present on the film surface strongly decreases with film depth. Deposited films also contain a significant amount of oxygen whose origin is not fully clear. Grazing incidence X-ray diffraction (GIXD) shows a Cu3N phase on the surface, while transmission electron microscopy (TEM) indicates a polycrystalline structure and the presence of a Ti3CuN phase