Why High Availability Clustering is awesome

This session will be an introduction to High Availability clustering, which is available in openSUSE and the SUSE Linux Enterprise High Availability Extension.
The talk will explain the basic concepts of high availability clustering, such as the Pacemaker Resource Manager, Corosync Cluster Engine, Resource Agents, Fencing Agents, and great acronyms like SBD (Storage Based Death) and STONITH (Shoot the other node in the head)

It will also give a very brief demonstration on how easy it is to setup a simple 2 node HA cluster on openSUSE 13.2 or Tumbleweed

Transcript

1. Clustering is Awesome Pacemakers, Death by Storage, and Shooting Servers in the Head Richard Brown - QA Engineer @ SUSE rbrown@opensuse.org
2. 2 About Me • QA Engineer at SUSE since November 2013 ‒ High Availability Clustering ‒ openQA • SysAdmin at a UK College since 2002 ‒ Early adopter of HA technologies • openSUSE contributor since 2005 ‒ Chairman of the Board
3. 3 Topics • Why do we need High Availability? • How it works • How to install it on openSUSE
4. Why do we need HA?
5. 5 What is HA? High Availability
6. 6 What is HA? “The definition of availability is Ao = up time / total time. This equation is not practical, but if (total time - down time) is substituted for up time then you have Ao = (total time - down time) / total time.” - Wikipedia (CC-BY-SA)
8. 8 But Linux is already stable!
9. 9 But Linux is already stable! “Linux has never been about quality. There are so many parts of the system that are just these cheap little hacks, and it happens to run.” - Theo de Raadt
12. 12 It's not just software or hardware that can let you down...
15. 15 Servers fail, no one else can help
16. 16 Servers don't really matter
17. 17 Services Matter, not Servers
18. How HA Works
21. 21 Server 1 Server 2
22. 22 Server 1 Server 2 Web Server Apache File Server Samba
23. 23 Server 1 Server 2 Web Server Apache File Server Samba
24. 24 Server 1 Server 2 Web Server Apache File Server Samba
25. 25 Server 1 Server 2 Web Server Apache File Server Samba Um, I still need my files
26. 26 Server 1 Server 2 Web Server Apache File Server Samba Local Disk Local Disk
27. 27 Server 1 Server 2 Web Server Apache File Server Samba Local Disk Local Disk RSYNC
28. 28 Server 1 Server 2 Web Server Apache File Server Samba Local Disk Local Disk DRBD
29. 29 Server 1 Server 2 Web Server Apache File Server Samba Shared Disk eg. FC/iSCSI
30. 30 Server 1 Server 2 Web Server Apache File Server Samba Shared Disk eg. FC/iSCSI Server 3 DB Server MariaDB
31. 31 Odd Number of servers = better
32. 32 Odd Number of servers = better
33. 33 Server 1 Server 2 Web Server Apache File Server Samba Shared Disk eg. FC/iSCSI Server 3 DB Server MariaDB
34. 34 Server 1 Server 2 Web Server Apache File Server Samba Local Disk Local Disk DRBD
35. Installation on openSUSE
36. 36 Installation • openSUSE Tumbleweed or 13.2 zypper in ha-cluster-bootstrap • On first server ha-cluster-init Wizard will ask you all the important questions • On other servers ha-cluster-join -c <ip of first server>
37. 37 Further Reading & Community • Documentation https://www.suse.com/documentation/sle-ha-12/ • DRBD http://drbd.linbit.com/ • IRC #ha-devel on Freenode • Mailing List opensuse-ha+subcribe@opensuse.org
38. 38 Have a Lot of Fun, and Join Us At: www.opensuse.org
39. General Disclaimer This document is not to be construed as a promise by any participating organisation to develop, deliver, or market a product. It is not a commitment to deliver any material, code, or functionality, and should not be relied upon in making purchasing decisions. openSUSE makes no representations or warranties with respect to the contents of this document, and specifically disclaims any express or implied warranties of merchantability or fitness for any particular purpose. The development, release, and timing of features or functionality described for openSUSE products remains at the sole discretion of openSUSE. Further, openSUSE reserves the right to revise this document and to make changes to its content, at any time, without obligation to notify any person or entity of such revisions or changes. All openSUSE marks referenced in this presentation are trademarks or registered trademarks of SUSE LLC, in the United States and other countries. All third-party trademarks are the property of their respective owners. License This slide deck is licensed under the Creative Commons Attribution-ShareAlike 4.0 International license. It can be shared and adapted for any purpose (even commercially) as long as Attribution is given and any derivative work is distributed under the same license. Details can be found at https://creativecommons.org/licenses/by-sa/4.0/ Credits Template Richard Brown rbrown@opensuse.org Design & Inspiration openSUSE Design Team http://opensuse.github.io/branding- guidelines/