EDBT 2026 Demo / reviewers in the wild / expert
Subru Krishnan
dblp:159/6290
· DBLP profile ↗
13ranked-venue papers in the field
0as first author
8since 2021 · last 2026
0009-0007-8534-0889ORCID · corroborated
Domains — venue-derived; a paper can count in several
Database Systems & Data Management · 10Data Mining & Knowledge Discovery · 2Information Retrieval & Web Search · 1
| Year | Publication | Venue | Position |
|---|---|---|---|
| 2026 | ENCO: Deploying Production-Scale Engineering CopilotsabstractSoftware engineers frequently grapple with the challenge of accessing fragmented documentation and telemetry data, such as Troubleshooting Guides (TSGs), incident reports, code repositories, and internal tools maintained by different teams. In this work, we introduced ENCO, a comprehensive framework for developing, deploying, and managing copilots tailored to improve productivity in large scale production scenarios. The framework combines an innovative NL2SearchQuery module with a lightweight hierarchical agentic planner to enable accurate and efficient retrieval-augmented generation (RAG) for code, semi-structured data and documents. These components allow the copilot to retrieve relevant information from diverse sources and invoke the right skills with low latency to answer highly complex technical questions. Since its launch in September 2023, ENCO has demonstrated its effectiveness through widespread adoption, enabling tens of thousands of interactions and engaging over 1,000 monthly active users (MAUs). The system has been continuously optimized based on usage patterns and user feedback, resulting in measurable improvements in response relevance, latency, and user satisfaction. Mathieu B. Demarne, Wenjing Wang 0005, Nutan Sahoo, Hannah Lerner, Anjali Bhavan, Divya Vermareddy, Yunlei Lu, Swati Bararia, William Zhang 0001, Katherine Lin, Miso Cilimdzic, Subru Krishnan |
KDD (1) | 15 |
| 2025 | FLAIR: Feedback Learning for Adaptive Information RetrievalabstractRecent advances in Large Language Models (LLMs) have driven the adoption of copilots in complex technical scenarios, underscoring the growing need for specialized information retrieval solutions. In this paper, we introduce FLAIR, a lightweight, feedback learning framework that adapts copilot systems' retrieval strategies by integrating domain-specific expert feedback. FLAIR operates in two stages: an offline phase obtains indicators from (1) user feedback and (2) questions synthesized from documentation, storing these indicators in a decentralized manner. An online phase then employs a two-track ranking mechanism to combine raw similarity scores with the collected indicators. This iterative setup refines retrieval performance for any query. Extensive real-world evaluations of FLAIR demonstrate significant performance gains on both previously seen and unseen queries, surpassing state-of-the-art approaches. The system has been successfully integrated into Copilot DECO, serving thousands of users at Microsoft, demonstrating its scalability and effectiveness in operational environments. William Zhang 0001, Yunlei Lu, Mathieu B. Demarne, Wenjing Wang 0005, Nutan Sahoo, Katherine Lin, Miso Cilimdzic, Subru Krishnan |
CIKM | 10 |
| 2024 | Lorentz: Learned SKU Recommendation Using Profile DataabstractIn response to diverse demands, cloud operators have significantly expanded the array of service offerings, often referred to as Stock Keeping Units (SKUs) available for computing resource configurations. Such diversity has led to increased complexity for customers to choose the appropriate SKU. In the analyzed system, only 43% of the resource capacity was rightly chosen. Although various automated solutions have attempted to resolve this issue, they often rely on the availability of enriched data, such as workload traces, which are unavailable for newly established services. Since these services amass a substantial volume of telemetry from existing users, cloud operators can leverage this information to better understand customer needs and mitigate the risk of over- or under-provisioning. Furthermore, customer satisfaction feedback serves as a crucial resource for continuous learning and improving the recommendation mechanism. In this paper, we present Lorentz, an intelligent SKU recommender for provisioning new compute resources that circumvents the need for workload traces. Lorentz leverages customer profile data to forecast resource capacities for new users based on detailed profiling of existing users. Furthermore, using a continuous learned feedback loop, Lorentz tailors capacity recommendations according to customer performance vs. cost preferences captured through satisfaction signals. Validated using the production data from provisioned VMs supporting Database Platform X, we demonstrate that Lorentz outperforms user selections and existing defaults, reducing slack by >60% without increasing throttling. Evaluated using synthetic data, Lorentz's personalization stage iteratively learns the user preferences over time with high accuracy. Nick Glaze, Tria McNeely, Matthew Gleeson, Helen Serr, Rajeev Bhopi, Subru Krishnan |
Proc. ACM Manag. Data | 7 |
| 2024 | Intelligent Pooling: Proactive Resource Provisioning in Large-scale Cloud ServiceabstractThe proliferation of big data and analytic workloads has driven the need for cloud compute and cluster-based job processing. With Apache Spark, users can process terabytes of data at ease with hundreds of parallel executors. Providing low latency access to Spark clusters and sessions is a challenging problem due to the large overheads of cluster creation and session startup. In this paper, we introduce Intelligent Pooling, a system for proactively provisioning compute resources to combat the aforementioned overheads. Our system (1) predicts usage patterns using an innovative hybrid Machine Learning (ML) model with low latency and high accuracy; and (2) optimizes the pool size dynamically to meet customer demand while reducing extraneous COGS. The proposed system auto-tunes its hyper-parameters to balance between performance and operational cost with minimal to no engineering input. Evaluated using large-scale production data, Intelligent Pooling achieves up to 43% reduction in cluster idle time compared to static pooling when targeting 99% pool hit rate. Currently deployed in production, Intelligent Pooling is on track to save tens of million dollars in COGS per year as compared to traditional pre-provisioned pools. Deepak Ravikumar, Alex Yeo, Aditya Lakra, Harsha Nagulapalli, Santhosh Ravindran, Steve Suh, Niharika Dutta, Andrew Fogarty, Yoonjae Park, Sumeet Khushalani, Arijit Tarafdar, Kunal Parekh, Subru Krishnan |
Proc. VLDB Endow. | 14 |
| 2023 | Stitcher: Learned Workload Synthesis from Historical Performance Footprints
Chengcheng Wan 0001, Joyce Cahoon, Wenjing Wang 0005, Katherine Lin, Sean Liu, Raymond Truong, Alexandra M. Ciortea, Konstantinos Karanasos, Subru Krishnan |
EDBT | 11 |
| 2023 | Schema Matching using Pre-Trained Language ModelsabstractSchema matching over relational data has been studied for more than two decades. However, the state-of-the-art methods do not address key modern-day challenges encountered in real customer scenarios, namely: 1) no access to the source (customer) data due to privacy constraints, 2) target schema with a much larger number of entities and attributes compared to the source schema, and 3) different but semantically equivalent entity and attribute names in the source and target schemata. In this paper, we address these shortcomings. Using real-world customer schemata, we demonstrate that existing linguistic matching approaches have low accuracy. Next, we propose the Learned Schema Mapper (LSM), a novel linguistic schema matching system that leverages the natural language understanding capabilities of pre-trained language models to improve the overall accuracy. Combining this with active learning and a smart attribute selection strategy that selects the most informative attributes for users to label, LSM can significantly reduce the overall human labeling cost. Experimental results demonstrate that users can correctly match their full schema while saving as much as 81% of the labeling cost compared to manual labeling. Avrilia Floratou, Joyce Cahoon, Subru Krishnan, Andreas Müller 0024, Dalitso Banda, Fotis Psallidas, Jignesh M. Patel |
ICDE | 4 |
| 2022 | Doppler: Automated SKU Recommendation in Migrating SQL Workloads to the CloudabstractSelecting the optimal cloud target to migrate SQL estates from on-premises to the cloud remains a challenge. Current solutions are not only time-consuming and error-prone, requiring significant user input, but also fail to provide appropriate recommendations. We present Doppler, a scalable recommendation engine that provides right-sized Azure SQL Platform-as-a-Service (PaaS) recommendations without requiring access to sensitive customer data and queries. Doppler introduces a novel price-performance methodology that allows customers to get a personalized rank of relevant cloud targets solely based on low-level resource statistics, such as latency and memory usage. Doppler supplements this rank with internal knowledge of Azure customer behavior to help guide new migration customers towards one optimal target. Experimental results over a 9-month period from prospective and existing customers indicate that Doppler can identify optimal targets and adapt to changes in customer workloads. It has also found cost-saving opportunities among over-provisioned cloud customers, without compromising on capacity or other requirements. Doppler has been integrated and released in the Azure Data Migration Assistant v5.5, which receives hundreds of assessment requests daily. Joyce Cahoon, Wenjing Wang 0005, Katherine Lin, Sean Liu, Raymond Truong, Chengcheng Wan 0001, Alexandra M. Ciortea, Sreraman Narasimhan, Subru Krishnan |
Proc. VLDB Endow. | 11 |
| 2021 | KEA: Tuning an Exabyte-Scale Data InfrastructureabstractMicrosoft's internal big-data infrastructure is one of the largest in the world---with over 300k machines running billions of tasks from over 0.6M daily jobs. Operating this infrastructure is a costly and complex endeavor, and efficiency is paramount. In fact, for over 15 years, a dedicated engineering team has tuned almost every aspect of this infrastructure, achieving state-of-the-art efficiency (>60% average CPU utilization across all clusters). Despite rich telemetry and strong expertise, faced with evolving hardware/software/workloads this manual tuning approach had reached its limit---we had plateaued. In this paper, we present KEA, a multi-year effort to automate our tuning processes to be fully data/model-driven. KEA leverages a mix of domain knowledge and principled data science to capture the essence of our cluster dynamic behavior in a set of machine learning (ML) models based on collected system data. These models power automated optimization procedures for parameter tuning, and inform our leadership in critical decisions around engineering and capacity management (such as hardware and data center design, software investments, etc.). We combine "observational'' tuning (i.e., using models to predict system behavior without direct experimentation) with judicious use of "flighting'' (i.e., conservative testing in production). This allows us to support a broad range of applications that we discuss in this paper. KEA continuously tunes our cluster configurations and is on track to save Microsoft tens of millions of dollars per year. At the best of our knowledge, this paper is the first to discuss research challenges and practical learnings that emerge when tuning an exabyte-scale data infrastructure. Subru Krishnan, Konstantinos Karanasos, Isha Tarte, Conor Power, Abhishek Modi, Deli Zhang, Kartheek Muthyala, Nick Jurgens, Sarvesh Sakalanaga, Sudhir Darbha, Minu Iyer, Ankita Agarwal, Carlo Curino |
SIGMOD Conference | 2 |
| 2020 | Cloudy with high chance of DBMS: a 10-year prediction for Enterprise-Grade ML
Ashvin Agrawal, Rony Chatterjee, Carlo Curino, Avrilia Floratou, Neha Godwal, Matteo Interlandi, Alekh Jindal, Konstantinos Karanasos, Subru Krishnan, Brian Kroth, Jyoti Leeka, Kwanghyun Park 0001, Hiren Patel, Olga Poppe, Fotis Psallidas, Raghu Ramakrishnan 0001, Abhishek Roy 0008, Karla Saur, Rathijit Sen, Markus Weimer, Travis Wright |
CIDR | 9 |
| 2020 | Extending Relational Query Processing with ML Inference
Konstantinos Karanasos, Matteo Interlandi, Fotis Psallidas, Rathijit Sen, Kwanghyun Park 0001, Ivan Popivanov, Doris Xin, Supun Nakandala, Subru Krishnan, Markus Weimer, Raghu Ramakrishnan 0001, Carlo Curino |
CIDR | 9 |
| 2020 | Vamsa: Automated Provenance Tracking in Data Science ScriptsabstractThere has recently been a lot of ongoing research in the areas of fairness, bias and explainability of machine learning (ML) models due to the self-evident or regulatory requirements of various ML applications. We make the following observation: All of these approaches require a robust understanding of the relationship between ML models and the data used to train them. In this work, we introduce the ML provenance tracking problem: the fundamental idea is to automatically track which columns in a dataset have been used to derive the features/labels of an ML model. We discuss the challenges in capturing such information in the context of Python, the most common language used by data scientists. Mohammad Hossein Namaki, Avrilia Floratou, Fotis Psallidas, Subru Krishnan, Ashvin Agrawal, Yinghui Wu 0001, Markus Weimer |
KDD | 4 |
| 2019 | Peering through the Dark: An Owl's View of Inter-job Dependencies and Jobs' Impact in Shared ClustersabstractShared multi-tenant infrastructures have enabled companies to consolidate workloads and data, increasing data-sharing and cross-organizational re-use of job outputs. This same resource- and work-sharing has also increased the risk of missed deadlines and diverging priorities as recurring jobs and workflows developed by different teams evolve independently. To prevent incidental business disruptions, identifying and managing job dependencies with clarity becomes increasingly important. Owl is a cluster log analysis and visualization tool that (i) extracts and visualizes job dependencies derived from historical job telemetry and data provenance data sets, and (ii) introduces a novel job valuation algorithm estimating the impact of a job on dependent users and jobs. This demonstration showcases Owl's features that can help users identify critical job dependencies and quantify job importance based on jobs' impact. Carlo Curino, Subru Krishnan, Konstantinos Karanasos, Panagiotis Garefalakis, Gregory R. Ganger |
SIGMOD Conference | 3 |
| 2019 | SparkCruise: Handsfree Computation Reuse in SparkabstractInteractive data analytics is often inundated with common computations across multiple queries. These redundancies result in poor query performance and higher overall cost for the interactive query sessions. Obviously, reusing these common computations could lead to cost savings. However, it is difficult for the users to manually detect and reuse the common computations in their fast moving interactive sessions. In the paper, we propose to demonstrate SparkCruise, a computation reuse system that automatically selects the most useful common computations to materialize based on the past query workload. SparkCruise materializes these computations as part of query processing, so the users can continue with their query processing just as before and computation reuse is automatically applied in the background --- all without any modifications to the Spark code. We will invite the audience to play with several scenarios, such as workload redundancy insights and pay-as-you-go materialization, highlighting the utility of SparkCruise. Abhishek Roy 0008, Alekh Jindal, Hiren Patel, Ashit Gosalia, Subru Krishnan, Carlo Curino |
Proc. VLDB Endow. | 5 |