Shreyas Kharbanda

Publications

1. EuroSys ’24

   Pronghorn: Effective Checkpoint Orchestration for Serverless Hot-Starts.

   Sumer Kohli*, Shreyas Kharbanda*, Rodrigo Bruno, Joao Carreira, and Pedro Fonseca

   In Proceedings of the 19th USENIX European Conference on Computer Systems, Athens, Greece, 2024.

   Abs HTML PDF

   Serverless computing allows developers to deploy and scale stateless functions in ephemeral workers easily. As a result, serverless computing has been widely used for many applications, such as HTML processing, computer vision, and video processing. However, we find that the stateless nature of serverless computing wastes many of the important benefits modern language runtimes have to offer. A notable example is the extensive profiling and Just-in-Time (JIT) compilation effort that runtimes implement to achieve acceptable performance of popular high-level languages, such as Java, and JavaScript, and Python. Unfortunately, when modern language runtimes are naively adopted in serverless computing, all of these efforts are lost upon worker eviction. Checkpoint-restore methods alleviate the problem by resuming workers from snapshots taken after initialization. However, production-grade language runtimes can take up to thousands of invocations to fully optimize a single function, thus rendering naive checkpoint-restore policies ineffective. This paper proposes Pronghorn, a snapshot serverless orchestrator that automatically monitors the function performance and decides (1) when it is the right moment to take a snapshot and (2) which snapshot to use for new workers. Pronghorn is agnostic to the underlying platform and JIT runtime, thus easing its integration into existing runtimes and worker deployment environments (container, virtual machine, etc.). On a set of representative serverless benchmarks, Pronghorn provides end-to-end median latency improvements of 37.2% across 9 out of 13 benchmarks (20-58% latency reduction) when compared to state-of-art checkpointing policies.

2. SESAME ’23

   Always-On Recording Framework for Serverless Computations: Opportunities and Challenges

   Shreyas Kharbanda, and Pedro Fonseca

   In Proceedings of the 1st Workshop on SErverless Systems, Applications and MEthodologies, Rome, Italy, 2023.

   Abs HTML PDF

   Serverless computing simplifies cloud programming by managing infrastructure and providing basic primitives for building distributed components. However, these efforts tend to increase complexity as developers create large, interdependent applications. The highly distributed nature of serverless computations makes it challenging for developers to comprehend the granular behavior of their applications. To address this problem, we present our vision for an always-on recording framework for serverless computations. Our goal is to efficiently capture low-level details of serverless computations by refining the ideas of traditional record-replay approaches while exploiting the properties of serverless environments. This envisioned approach is poised to provide greater serverless computation visibility for developers to diagnose faults, understand interactions between components, conduct performance analysis, and ensure security and efficiency. Fully tapping this potential will require exploring several research directions, ranging from low-cost recording, storage, and data management systems to practical replay analysis tools.