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)


When carrying out benchmarks, you are ultimately measuring the result of latency. All other forms of benchmarking metrics, including IOPS, MBps, or even higher level application metrics, are derived from the latency of that request.

IOPS are the number of I/O requests done in a second; the latency of each request directly effects the possible IOPS and can be seen by this formula:

An average latency of 2 milliseconds per request will result in roughly 500 IOPS assuming each request is submitted in a synchronous fashion:

1/0.002 = 500

MBps is simply the number of IOPS multiplied by the I/O size:

500 IOPS * 64 KB = 32,000 KBps

It should be clear that when you are carrying out benchmarks, you are actually measuring the end result of a latency. Therefore, any tuning that you are carrying out should be done to reduce end-to-end latency for each I/O request.

Before moving on to looking at how to benchmark various...