Yong Xiang is a PhD student at Tsinghua University. This episode is a recording of his talk during APSys 2016, the Asia-Pacific Workshop on Systems, on Aug. 5, based on Debugging OpenStack Problems Using a State Graph Approach, written with co-authors Hu Li, Sen Wang, Charley Peter Chen, and Wei Xu, which was awarded “best paper” at the conference. A preprint of the paper is also available at arxiv.org.

Slides from the talk are available. It is probably easier to follow the talk if you have the slides available, but it is certainly not necessary.

This is a very practical paper that seeks ways to make it easier for non-experts to troubleshoot and debug an OpenStack deployment. Its abstract is:

It is hard to operate and debug systems like OpenStack that integrate many independently developed modules with multiple levels of abstractions. A major challenge is to navigate through the complex dependencies and relationships of the states in different modules or subsystems, to ensure the correctness and consistency of these states. We present a system that captures the runtime states and events from the entire OpenStack-Ceph stack, and automatically organizes these data into a graph that we call system operation state graph (SOSG). With SOSG we can use intuitive graph traversal techniques to solve problems like reasoning about the state of a virtual machine. Also, using a graph-based anomaly detection, we can automatically discover hidden problems in OpenStack. We have a scalable implementation of SOSG, and evaluate the approach on a 125-node production OpenStack cluster, finding a number of interesting problems.

The first question at the end of the talk comes from me, with an answer assisted by the paper's coauthor Wei Xu, and the second one from Sorav Bansal.

OVS Orbit is produced by Ben Pfaff. The intro music in this episode is Drive, featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper music is Yeah Ant featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro music is Space Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All content is licensed under a Creative Commons Attribution 3.0 Unported (CC BY 3.0) license.