Book Image

Mastering Ceph

By : Nick Fisk
Book Image

Mastering Ceph

By: Nick Fisk

Overview of this book

Mastering Ceph covers all that you need to know to use Ceph effectively. Starting with design goals and planning steps that should be undertaken to ensure successful deployments, you will be guided through to setting up and deploying the Ceph cluster, with the help of orchestration tools. Key areas of Ceph including Bluestore, Erasure coding and cache tiering will be covered with help of examples. Development of applications which use Librados and Distributed computations with shared object classes are also covered. A section on tuning will take you through the process of optimisizing both Ceph and its supporting infrastructure. Finally, you will learn to troubleshoot issues and handle various scenarios where Ceph is likely not to recover on its own. By the end of the book, you will be able to successfully deploy and operate a resilient high performance Ceph cluster.
Table of Contents (12 chapters)

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...