15 research outputs found
LibrettOS: A Dynamically Adaptable Multiserver-Library OS
We present LibrettOS, an OS design that fuses two paradigms to simultaneously
address issues of isolation, performance, compatibility, failure
recoverability, and run-time upgrades. LibrettOS acts as a microkernel OS that
runs servers in an isolated manner. LibrettOS can also act as a library OS
when, for better performance, selected applications are granted exclusive
access to virtual hardware resources such as storage and networking.
Furthermore, applications can switch between the two OS modes with no
interruption at run-time. LibrettOS has a uniquely distinguishing advantage in
that, the two paradigms seamlessly coexist in the same OS, enabling users to
simultaneously exploit their respective strengths (i.e., greater isolation,
high performance). Systems code, such as device drivers, network stacks, and
file systems remain identical in the two modes, enabling dynamic mode switching
and reducing development and maintenance costs.
To illustrate these design principles, we implemented a prototype of
LibrettOS using rump kernels, allowing us to reuse existent, hardened NetBSD
device drivers and a large ecosystem of POSIX/BSD-compatible applications. We
use hardware (VM) virtualization to strongly isolate different rump kernel
instances from each other. Because the original rumprun unikernel targeted a
much simpler model for uniprocessor systems, we redesigned it to support
multicore systems. Unlike kernel-bypass libraries such as DPDK, applications
need not be modified to benefit from direct hardware access. LibrettOS also
supports indirect access through a network server that we have developed.
Applications remain uninterrupted even when network components fail or need to
be upgraded. Finally, to efficiently use hardware resources, applications can
dynamically switch between the indirect and direct modes based on their I/O
load at run-time.
[full abstract is in the paper]Comment: 16th ACM SIGPLAN/SIGOPS International Conference on Virtual Execution
Environments (VEE '20), March 17, 2020, Lausanne, Switzerlan
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys
Mach: A New Kernel Foundation for UNIX Development
Mach is a multiprocessor operating system kernel and environment under development at Carnegie Mellon University. Mach provides a new foundation for UNIX development that spans networks of uniprocessors and multiprocessors. This paper describes Mach and the motivations that led to its design. Also described are some of the details of its implementation and current status.