This is the second in our two-part series on the SUSE High Availability Extension. Read Part 1 Do You Have the Right Failover plan for your critical applications to learn more about the solution and how it can help you take the costs out of downtime.
What features come with the High Availability Extension suite? (Besides a mini bar)
There are a lot of components to choose from with this offering, so I have broken them down below with a short explanation for each. If you prefer a visual explanation, you can watch a video demo. Also, read on to find out what we like about this failover solution.
1. A policy-driven cluster resource manager:
- Pacemaker is a highly scalable cluster resource manager with a flexible policy engine that supports n-node clusters. Using Pacemaker, you can continuously monitor the health of your resources, manage dependencies, and automatically stop and start services based on highly configurable rules and policies.
- OpenAIS is the leading standards-based communication protocol for server and storage clustering, and is easily integrates with other infrastructure software.
- Corosync is the Open Source Initiative’s certified implementation of a complete cluster engine and is supported alongside OpenAIS. It provides membership, ordered messaging with virtual synchrony guarantees, closed process communication groups, and an extendable framework. Corosync will support unicast and multicast communication. The addition of unicast communication will reduce the requirements for cluster installation by eliminating the need to implement specific configurations for multicast enabled network components.
2. Cluster-aware file system and volume management:
- Oracle Cluster File System 2 (OCFS2) is a shared-disk, POSIX-compliant, generic cluster file system. Using OCFS2, you can cluster a much wider range of applications for higher availability using cluster-aware POSIX locking, as well as resize your clusters and add new nodes on the fly. Cluster-aware applications are also able to use parallel I/O for higher performance.
- Clustered Logical Volume Manager 2 (cLVM2) provides a more convenient, single, cluster wide view of storage. Clustering extensions to the standard LVM2 toolset allow existing LVM2 commands to safely and simply manage shared storage, eliminating the need to learn a new set of tools.
3. Continuous data replication and node recovery:
- DRBD (Distributed Replicated Block Device) is a leading open source networked disk management tool. Using DRBD, you can build single partitions from multiple disks that mirror each other, and make data highly available. Learn more about DRBD
- Also included is Relax and Recover (ReaR), a popular open source node recovery framework, for quick bare metal restorations.
- Included at no additional charge, these components are scripts for monitoring popular open source services, such as Apache, CTDB, MySQL, NFS, PostgreSQL, Tomcat and KVM, Xen.
Also included are scripts for third-party applications, such as SAP Instance and Database, Oracle Database, IBM DB2, Informix Dynamic Server, WebSphere Application Server, and VMware. With these components, you can quickly and easily set up many highly available data center services, using physical and virtual systems.
4. User-centric management tools:
A powerful unified command-line interface is included for experienced IT managers to quickly and easily install, configure and manage their clustered Linux servers. Also provided is a graphical user interface to give operators a streamlined, user-friendly tool for monitoring and administering their clustered environment. YaST modules are also included for the configuration of DRBD, OpenAIS, and multipath. These modules help IT managers improve productivity and more easily configure distributed storage systems and high availability solutions.
Remember: with this solution you need both SUSE Linux Enterprise Server and SUSE Linux Enterprise High Availability Extension to set up highly available Linux clusters
Why we like this suite:
Meet your SLAs: You can implement and configure a variety of clustered solutions to provide continuous access to your most mission critical applications. Virtual servers can even be clustered with physical servers to simultaneously improve services availability and resource utilization.
Ensure continuous access to mission-critical systems and data: You can use high availability clustering to automate application and data recovery. You can use the integrated suite of innovative open source clustering technologies in SUSE Linux Enterprise High Availability Extension to implement highly available Linux clusters and eliminate single points of failure. When a fault or failure occurs, the workload is transferred from one server to another, or the application is automatically restarted on a known working system.
Maintain data integrity: Deliver continuous, real-time replication of data, ensuring that multiple copies of data are available at all times. The ability to incrementally synchronize large databases and data repositories reduces data recovery times. Built-in locking mechanisms ensure data integrity by only allowing one application to access shared storage at a time.
In short: It’s an affordable suite of open source clustering technologies that allows you to build highly available virtual and physical Linux clusters. Do you have more questions? Check out this FAQ sheet with some good explanations about how the details work together and answers to problems you may run into.
Want to get the nitty gritty? Download the SUSE Linux Enterprise High Availability Extension Guide
How do I get started?
Contact your Softchoice Account Representative to discuss a SUSE solution, or leave a comment below with your questions. Our team will respond as soon as possible.