Red Hat Collaboratory Colloquium Series: Adam Belay, LDB: An Efficient, Full-Program Latency Profiler
Maintaining low tail latency is critical for the efficiency and performance of large-scale datacenter systems. Software bugs that cause tail latency problems, however, are notoriously difficult to debug. In this talk, I will present LDB, a new latency profiling tool that aims to overcome this challenge by precisely identifying the specific functions that are responsible for tail latency anomalies. LDB observes the latency of all functions in a running program. It uses a novel, software-only technique called stack sampling, where a busy-spinning stack scanner thread polls light-weight metadata recorded in call frames, shifting instrumentation cost away from program threads. In addition, LDB records request boundaries and inter-thread synchronization to generate per-request timelines and to find the root cause of complex tail latency problems such as lock contention in multi-threaded programs. Our results show that LDB has low overhead and can rapidly analyze recordings, making it feasible to use in production settings.
Adam Belay is an Associate Professor of Computer Science at the Massachusetts Institute of Technology, where he works on operating systems, runtime systems, and distributed systems. During his Ph.D. at Stanford, he developed Dune, a system that safely exposes privileged CPU instructions to userspace; and IX, a dataplane operating system that significantly accelerates I/O performance. Dr. Belay’s current research interests lie in developing systems that cut across hardware and software layers to increase datacenter efficiency and performance. He is a member of the Parallel and Distributed Operating Systems Group, and a recipient of a Google Faculty Award, a Facebook Research Award, and the Stanford Graduate Fellowship. http://abelay.me
Lunch will be available
Center for Data Sciences (CDS)
665 Commonwealth Ave
Room 1101 (note this was updated)
Boston, MA 02215
Click to access meeting via Zoom
If the direct link doesn’t work use Meeting ID: 944 0022 9257; Passcode: 564023
About the Collaboratory
A partnership between Red Hat and Boston University, the Red Hat Collaboratory connects BU faculty and students with industry practitioners working in open-source software communities. The Collaboratory aims to advance research focused on emerging technologies in a number of areas including operating systems, cloud computing services, machine learning and automation, and big data platforms.