ORESTES: a Scalable Database-as-a-Service Architecture for Low Latency

Abstract-Today, the applicability of database systems in cloud environments is considerably restricted because of three major problems: I) high network latencies for remote/mobile clients, II) lack of elastic horizontal scalability mechanisms, and III) missing abstraction of storage and data models. In this paper, we propose an architecture, a REST/HTTP protocol and a set of algorithms to solve these problems through a Database-as-a-Service middleware called ORESTES (Objects RESTfully Encapsulated in Standard Formats). ORESTES exposes cloud-hosted NoSQL database systems through a scalable tier of REST servers. These provide database-independent, object-oriented schema design, a client-independent REST-API for database operations, globally distributed caching, cache consistency mechanisms and optimistic ACID transactions. By comparative evaluations we offer empirical evidence that the proposed Database-as-a-Service architecture indeed solves common latency, scalability and abstraction problems encountered in modern cloud-based applications. I. INTRODUCTION The emergence of cloud computing, Database-as-a-Service (DBaaS) and "NoSQL" databases has demonstrated a clear demand for scalable database systems with cloud-capable, webbased interfaces Different studies have shown the dramatic effect of latency on user behavior. For instance, Amazon found that an additional latency of 100ms resulted in 1% less revenue and Google measured that increasing the load time of search results by 500ms decreased user traffic by 20% ORESTES (Objects RESTfully Encapsulated in Standard Formats) is our proposed BaaS/DBaaS architecture to overcome these current limitations of the Backend-as-a-Service model. ORESTES targets the read-intensive, latency-sensitiv

ORESTES: a Scalable Database-as-a-Service Architecture for Low Latency

Abstract-Today, the applicability of database systems in cloud environments is considerably restricted because of three major problems: I) high network latencies for remote/mobile clients, II) lack of elastic horizontal scalability mechanisms, and III) missing abstraction of storage and data models. In this paper, we propose an architecture, a REST/HTTP protocol and a set of algorithms to solve these problems through a Database-as-a-Service middleware called ORESTES (Objects RESTfully Encapsulated in Standard Formats). ORESTES exposes cloud-hosted NoSQL database systems through a scalable tier of REST servers. These provide database-independent, object-oriented schema design, a client-independent REST-API for database operations, globally distributed caching, cache consistency mechanisms and optimistic ACID transactions. By comparative evaluations we offer empirical evidence that the proposed Database-as-a-Service architecture indeed solves common latency, scalability and abstraction problems encountered in modern cloud-based applications. I. INTRODUCTION The emergence of cloud computing, Database-as-a-Service (DBaaS) and "NoSQL" databases has demonstrated a clear demand for scalable database systems with cloud-capable, webbased interfaces Different studies have shown the dramatic effect of latency on user behavior. For instance, Amazon found that an additional latency of 100ms resulted in 1% less revenue and Google measured that increasing the load time of search results by 500ms decreased user traffic by 20% ORESTES (Objects RESTfully Encapsulated in Standard Formats) is our proposed BaaS/DBaaS architecture to overcome these current limitations of the Backend-as-a-Service model. ORESTES targets the read-intensive, latency-sensitiv

New investigations at the Middle Stone Age site of Pockenbank Rockshelter, Namibia

In southern Africa, Middle Stone Age sites with long sequences have been the focus of intense international and interdisciplinary research over the past decade (cf. Wadley 2015). Two techno-complexes of the Middle Stone Agethe Still Bay and Howiesons Poorthave been associated with many technological and behavioural innovations of Homo sapiens. The classic model argues that these two techno-complexes are temporally separated horizons' with homogenous material culture (Jacobs et al.2008), reflecting demographic pulses and supporting large subcontinental networks. This model was developed on the basis of evidence from southern African sites regarded as centres of subcontinental developments