Book Image

Ceph: Designing and Implementing Scalable Storage Systems

By : Michael Hackett, Vikhyat Umrao, Karan Singh, Nick Fisk, Anthony D'Atri, Vaibhav Bhembre
Book Image

Ceph: Designing and Implementing Scalable Storage Systems

By: Michael Hackett, Vikhyat Umrao, Karan Singh, Nick Fisk, Anthony D'Atri, Vaibhav Bhembre

Overview of this book

This Learning Path takes you through the basics of Ceph all the way to gaining in-depth understanding of its advanced features. You’ll gather skills to plan, deploy, and manage your Ceph cluster. After an introduction to the Ceph architecture and its core projects, you’ll be able to set up a Ceph cluster and learn how to monitor its health, improve its performance, and troubleshoot any issues. By following the step-by-step approach of this Learning Path, you’ll learn how Ceph integrates with OpenStack, Glance, Manila, Swift, and Cinder. With knowledge of federated architecture and CephFS, you’ll use Calamari and VSM to monitor the Ceph environment. In the upcoming chapters, you’ll study the key areas of Ceph, including BlueStore, erasure coding, and cache tiering. More specifically, you’ll discover what they can do for your storage system. In the concluding chapters, you will develop applications that use Librados and distributed computations with shared object classes, and see how Ceph and its supporting infrastructure can be optimized. By the end of this Learning Path, you'll have the practical knowledge of operating Ceph in a production environment. This Learning Path includes content from the following Packt products: • Ceph Cookbook by Michael Hackett, Vikhyat Umrao and Karan Singh • Mastering Ceph by Nick Fisk • Learning Ceph, Second Edition by Anthony D'Atri, Vaibhav Bhembre and Karan Singh
Table of Contents (27 chapters)
Title Page
About Packt
Contributors
Preface
Index

How BlueStore works


The following diagram shows how Bluestore interacts with a block device. Unlike filestore, data is directly written to the block device and metadata operations are handled by RocksDB.

RocksDB

RocksDB is a high-performance key value store, which was originally forked from LevelDB, but after development, Facebook went on to offer significant performance improvements suited for multiprocessor servers with low latency storage devices. It has also had numerous feature enhancements, some of which are used in BlueStore.

RocksDB is used to store metadata about the stored objects, which was previously handled by a combination of LevelDB and XATTRs in filestore.

A feature of RocksDB, which BlueStore takes advantage of, is the ability to store the WAL on a faster storage device, which can help to lower latency of RocksDB operations. This also hopefully improves Ceph's performance, particularly for smaller I/Os. This gives a number of possible storage layout configurations, where the...