Deep learning (DL) has revolutionized unstructured data analytics. But in most cases, DL needs massive labeled datasets and large compute clusters, which hinders its adoption. These limitations can be overcome using a popular paradigm called deep transfer learning (DTL). With DTL, one adapts a pre-trained DL model instead of training a model from scratch. Thus, DTL reduces the massive training data and compute requirements to train a model. During adaptation, a common practice is to freeze most pre-trained model parts and adapt only the remaining. Since no single adaptation scheme is universally the best, one often evaluates several schemes, which is also called model selection. We also observed that data labeling for DTL is seldom a one-off process. One often updates their labeled data intermittently by adding new labeled data and performs model selection to evaluate the accuracy of the trained models. Today, one executes this workload by performing computations for the entire pre-trained model and repeats it for every model selection cycle. This approach results in redundant computations in frozen model parts and causes usability and system inefficiency issues. In this work, we reimagine DTL model selection in the presence of frozen layers as an instance of multi-query optimization and propose two optimizations that reduce redundant computations and training overheads. We implement our optimizations into a data system called Nautilus. Experiments with end-to-end workloads on benchmark datasets show that Nautilus reduces DTL model selection runtimes by up to 5X compared to the current practice.

The huge demand for computation in artificial intelligence (AI) is driving unparalleled investments in hardware and software systems for AI. This leads to an explosion in the number of specialized hardware devices, which are now offered by major cloud vendors. By hiding the low-level complexity through a tensor-based interface, tensor computation runtimes (TCRs) such as PyTorch allow data scientists to efficiently exploit the exciting capabilities offered by the new hardware. In this paper, we explore how database management systems can ride the wave of innovation happening in the AI space. We design, build, and evaluate Tensor Query Processor (TQP): TQP transforms SQL queries into tensor programs and executes them on TCRs. TQP is able to run the full TPC-H benchmark by implementing novel algorithms for relational operators on the tensor routines. At the same time, TQP can support various hardware while only requiring a fraction of the usual development effort. Experiments show that TQP can improve query execution time by up to 10X over specialized CPU- and GPU-only systems. Finally, TQP can accelerate queries mixing ML predictions and SQL end-to-end, and deliver up to 9X speedup over CPU baselines.

Deep Learning (DL) has created a growing demand for simpler ways to develop complex models and efficient ways to execute them. Thus, a significant effort has gone into frameworks like PyTorch or TensorFlow to support a variety of DL models and run efficiently and seamlessly over heterogeneous and distributed hardware. Since these frameworks will continue improving given the predominance of DL workloads, it is natural to ask what else can be done with them. This is not a trivial question since these frameworks are based on the efficient implementation of tensors, which are well adapted to DL but, in principle, to nothing else. In this paper we explore to what extent Tensor Computation Runtimes (TCRs) can support non-ML data processing applications, so that other use cases can take advantage of the investments made on TCRs. In particular, we are interested in graph processing and relational operators, two use cases very different from ML, in high demand, and complement quite well what TCRs can do today. Building on HUMMINGBIRD, a recent platform converting traditional machine learning algorithms to tensor computations, we explore how to map selected graph processing and relational operator algorithms into tensor computations. Our vision is supported by the results: our code often outperforms custom-built C++ and CUDA kernels, while massively reducing the development effort, taking advantage of the cross-platform compilation capabilities of TCRs.

Deep learning (DL) is revolutionizing many fields. However, there is a major bottleneck for the wide adoption of DL: the pain of model selection , which requires exploring a large config space of model architecture and training hyper-parameters before picking the best model. The two existing popular paradigms for exploring this config space pose a false dichotomy. AutoML-based model selection explores configs with high-throughput but uses human intuition minimally. Alternatively, interactive human-in-the-loop model selection completely relies on human intuition to explore the config space but often has very low throughput. To mitigate the above drawbacks, we propose a new paradigm for model selection that we call intermittent human-in-the-loop model selection . In this demonstration, we will showcase our approach using five real-world DL model selection workloads. A short video of our demonstration can be found here: https://youtu.be/K3THQy5McXc.

We discovered that there was an inconsistency in the communication cost formulation for the decentralized fine-grained training method in Table 2 of our paper [1]. We used Horovod as the archetype for decentralized fine-grained approaches, and its correct communication cost is higher than what we had reported. So, we amend the communication cost of decentralized fine-grained to [EQUATION]

Scalable systems for machine learning (ML) are largely siloed into dataflow systems for structured data and deep learning systems for unstructured data. This gap has left workloads that jointly analyze both forms of data with poor systems support, leading to both low system efficiency and grunt work for users. We bridge this gap for an important class of such workloads: feature transfer from deep convolutional neural networks (CNNs) for analyzing images along with structured data. Executing feature transfer on scalable dataflow and deep learning systems today faces two key systems issues: inefficiency due to redundant computations and crash-proneness due to mismanaged memory. We present Vista, a new data system that resolves these issues by elevating this workload to a declarative level on top of dataflow and deep learning systems. Vista automatically optimizes the configuration and execution of this workload to reduce both computational redundancy and the potential for workload crashes. Experiments on real datasets show that apart from making feature transfer easier, Vista avoids workload crashes and reduces runtimes by 58% to 92% compared to baselines.

Deep learning now offers state-of-the-art accuracy for many prediction tasks. A form of deep learning called deep convolutional neural networks (CNNs) are especially popular on image, video, and time series data. Due to its high computational cost, CNN inference is often a bottleneck in analytics tasks on such data. Thus, a lot of work in the computer architecture, systems, and compilers communities study how to make CNN inference faster. In this work, we show that by elevating the abstraction level and re-imagining CNN inference as queries , we can bring to bear database-style query optimization techniques to improve CNN inference efficiency. We focus on tasks that perform CNN inference repeatedly on inputs that are only slightly different . We identify two popular CNN tasks with this behavior: occlusion-based explanations (OBE) and object recognition in videos (ORV). OBE is a popular method for “explaining” CNN predictions. It outputs a heatmap over the input to show which regions (e.g., image pixels) mattered most for a given prediction. It leads to many re-inference requests on locally modified inputs. ORV uses CNNs to identify and track objects across video frames. It also leads to many re-inference requests. We cast such tasks in a unified manner as a novel instance of the incremental view maintenance problem and create a comprehensive algebraic framework for incremental CNN inference that reduces computational costs. We produce materialized views of features produced inside a CNN and connect them with a novel multi-query optimization scheme for CNN re-inference. Finally, we also devise novel OBE-specific and ORV-specific approximate inference optimizations exploiting their semantics. We prototype our ideas in Python to create a tool called Krypton that supports both CPUs and GPUs. Experiments with real data and CNNs show that Krypton reduces runtimes by up to 5× (respectively, 35×) to produce exact (respectively, high-quality approximate) results without raising resource requirements.

Eating is a health-related behavior that could be intervened upon in the moment using smartphone technology, however predicting eating events using sensor data is challenging. We evaluate multiple machine learning algorithms for predicting eating and food purchasing events in a pilot sample of free living individuals. Data was collected with accelerometer, GPS device, and body-worn cameras for a week from 81 individuals. Raw minute-level features from sensors and engineered features including temporal and environmental context were included in the models. The Gradient Boosting model performed best for predicting eating, and the RBF-SVM model best predicted food purchasing. Time and context engineered features were important contributors to predicting eating and food purchasing events. This study provides a promising start in integrating body-worn sensor data, time components, and environmental contextual data into food-related behavior prediction for use in smartphone interventions.

Deep Convolutional Neural Networks (CNNs) now match human accuracy in many image prediction tasks, resulting in a growing adoption in e-commerce, radiology, and other domains. Naturally, explaining CNN predictions is a key concern for many users. Since the internal workings of CNNs are unintuitive for most users, occlusion-based explanations (OBE) are popular for understanding which parts of an image matter most for a prediction. One occludes a region of the image using a patch and moves it around to produce a heat map of changes to the prediction probability. Alas, this approach is computationally expensive due to the large number of re-inference requests produced, which wastes time and raises resource costs. We tackle this issue by casting the OBE task as a new instance of the classical incremental view maintenance problem. We create a novel and comprehensive algebraic framework for incremental CNN inference combining materialized views with multi-query optimization to reduce computational costs. We then present two novel approximate inference optimizations that exploit the semantics of CNNs and the OBE task to further reduce runtimes. We prototype our ideas in Python to create a tool we call Krypton that supports both CPUs and GPUs. Experiments with real data and CNNs show that Krypton reduces runtimes by up to 5X (resp. 35X) to produce exact (resp. high-quality approximate) results without raising resource requirements.

In this demonstration, we present Krypton, a system for accelerating occlusion-based deep convolution neural network (CNN) explanation workloads. Driven by the success of CNNs in image understanding tasks, there is growing adoption of CNNs in various domains, including high stakes applications such as radiology. However, users of such applications often seek an "explanation" for why a CNN predicted a certain label. One of the most widely used approaches for explaining CNN predictions is the occlusion-based explanation (OBE) method. This approach is computationally expensive due to the large number of re-inference requests produced. Krypton reduces the runtime of OBE by up to 35x by enabling incremental and approximate inference optimizations that are inspired by classical database query optimization techniques. We allow the audience to interactively diagnose CNN predictions from several use cases, including radiology and natural images. A short video of our demonstration can be found here: https://youtu.be/1OWddbd4n6Y

eScience middleware frameworks integrating multiple virtual organizations must incorporate comprehensive user identity and access management solutions. In this paper we examine usage patterns for these systems and map the patterns to widely used security standards and approaches. We focus on science gateways, a class of distributed system cyberinfrastructure. Science gateways are end user environments that provide access to a wide range of academic and commercial computing and storage resources for virtual organizations. Successful gateways focus on specific scientific communities and domains, but they build on many reusable features that can be provided by general purpose hosted platform services that can support multiple tenants. Providing a security framework for identity and access management for such hosted service removes the burden for each gateway to handle its user identity management and control access to its critical resources. From the resource provider's point of view, it provides a basis for more uniform accounting and auditing. Challenges arise from the range of gateways (both legacy and newly created), the range of technologies used to build them, and the range of end user environments (Web, mobile, desktop, and programmatic API clients) that gateways provide. Using Apache Airavata as an implementation, we examine three common gateway types based on where the user identity information is held and how these can be treated in a unified manner using OAuth2 and OpenID-Connect. Our solutions for identity and access management are not specific to Apache Airavata but can be generally applied to any e-Science platform.