The ever-increasing demand for high performance Big Data analytics and data processing, has paved the way for heterogeneous hardware accelerators, such as Graphics Processing Units (GPUs) and Field Programmable Gate Arrays (FPGAs), to be integrated into modern Big Data platforms. Currently, this integration comes at the cost of programmability since the end-user Application Programming Interface (APIs) must be altered to access the underlying heterogeneous hardware. For example, current Big Data frameworks, such as Apache Spark, provide a new API that combines the existing Spark programming model with GPUs. For other Big Data frameworks, such as Flink, the integration of GPUs and FPGAs is achieved via external API calls that bypass their execution models completely. In this paper, we rethink current Big Data frameworks from a systems and programming language perspective, and introduce a novel co-designed approach for integrating hardware acceleration into their execution models. The novelty of our approach is attributed to two key design decisions: a) support for arbitrary User Defined Functions (UDFs), and b) no modifications to the user level API. The proposed approach has been prototyped in the context of Apache Flink, and enables unmodified applications written in Java to run on heterogeneous hardware, such as GPU and FPGAs, transparently to the users. The performance evaluation of the proposed solution has shown performance speedups of up to 65x on GPUs and 184x on FPGAs for suitable workloads of standard benchmarks and industrial use cases against vanilla Flink running on traditional multi-core CPUs.

Modern large-scale computing deployments consist of complex elastic applications running over machine clusters. A current trend adopted by providers is to set unused virtual machines, or else spot instances, in low prices to take advantage of spare capacity. In this paper we present a group of efficient allocation and pricing policies that can be used by vendors for their spot price mechanisms. We model the procedure of acquiring virtual machines as a truthful knapsack auction and we deploy dynamic allocation and pricing rules that achieve near-optimal revenue and social welfare. As the problem is NP-hard our solutions are based on approximate algorithms. First, we propose two solutions that do not use prior knowledge. Then, we enhance them with three learning algorithms. We evaluate them with simulations on the Google Cluster dataset and we benchmark them against the Uniform Price, the Optimal Single Price and the Ex-CORE mechanisms. Our proposed dynamic mechanism is robust, achieves revenue up to 89% of the Optimal Single Price auction, and computes the allocation in polynomial time making our contribution computationally tractable in realtime scenarios.

Modern large scale computer clusters benefit significantly from elasticity. Elasticity allows a cluster to dynamically allocate computer resources, based on the user's fluctuating workload demands. Many cloud providers use threshold-based approaches, which have been proven to be difficult to configure and optimise, while others use reinforcement learning and decision-tree approaches, which struggle when having to handle large multidimensional cluster states. In this work we use Deep Reinforcement learning techniques to achieve automatic elasticity. We use three different approaches of a Deep Reinforcement learning agent, called DERP (Deep Elastic Resource Provisioning), that takes as input the current multi-dimensional state of a cluster and manages to train and converge to the optimal elasticity behaviour after a finite amount of training steps. The system automatically decides and proceeds on requesting/releasing VM resources from the provider and orchestrating them inside a NoSQL cluster according to user-defined policies/rewards. We compare our agent to state-of-the-art, Reinforcement learning and decision-tree based, approaches in demanding simulation environments and show that it gains rewards up to 1.6 times better on its lifetime. We then test our approach in a real life cluster environment and show that the system resizes clusters in real-time and adapts its performance through a variety of demanding optimisation strategies, input and training loads.

Modern Big Data processing systems, scheduling platforms and cloud infrastructures employ specialized hardware accelerators such as GPUs, FPGAs, TPUs, ASICs, etc. to optimize the execution of resource intensive workloads such as Machine Learning, Artificial Intelligence or generic Data Analytics tasks. Nevertheless, this support is mostly a user-dependent, manual process that requires careful and educated decisions on both the amount and type of required resources to exploit the underlying hardware and achieve any user-defined higher level policies. In this work we present the initial design of the HeterogeneRous Scheduler (HRS), an intelligent scheduler that can make automated decisions on both how and where to map arbitrary data analytics tasks to underlying cloud hardware that may consist of a mix of hardware accelerators and clusters with general purpose CPUs. We experimentally evaluate the performance trade-offs between hardware accelerators and CPUs where we show that there are cases where one technology outperforms the other. We finally present an initial architecture of HRS where we depict its different components and their interactions with the Big Data framework and the cloud infrastructure.