SUSE Linux Enterprise High Availability Extension 12 SP2

Release Notes

SUSE Linux Enterprise High Availability Extension is a suite of clustering technologies that enable enterprises to implement highly available Linux clusters and eliminate single points of failure. This document gives an overview of features of SUSE Linux Enterprise High Availability Extension and their limitations. Some sections do not apply to a particular architecture or product, this is explicitly marked.

Manuals can be found in the docu directory of the installation media, or in the directory /usr/share/doc/ on the installed system (if installed).

Publication Date: 2016-10-25, Version: 12.2.20161007

1 SUSE Linux Enterprise High Availability Extension

SUSE Linux Enterprise High Availability Extension is an affordable, integrated suite of robust open source clustering technologies that enable enterprises to implement highly available Linux clusters and eliminate single points of failure.

Used with SUSE Linux Enterprise Server, it helps firms maintain business continuity, protect data integrity, and reduce unplanned downtime for their mission-critical Linux workloads.

SUSE Linux Enterprise High Availability Extension provides all of the essential monitoring, messaging, and cluster resource management functionality of proprietary third-party solutions, but at a more affordable price, making it accessible to a wider range of enterprises.

It is optimized to work with SUSE Linux Enterprise Server, and its tight integration ensures customers have the most robust, secure, and up to date high availability solution. Based on an innovative, highly flexible policy engine, it supports a wide range of clustering scenarios.

With static or stateless content, the High Availability cluster can be used without a cluster file system. This includes web-services with static content as well as printing systems or communication systems like proxies that do not need to recover data.

Finally, its open source license minimizes the risk of vendor lock-in, and its adherence to open standards encourages interoperability with industry standard tools and technologies.

2 What Is New?

Cluster File System

GFS2 cluster file system with read/write support, to complement the SUSE recommended OCFS2 cluster file system.

Load balancer

HAProxy as layer 4 load balancer added, to complement the Linux virtual server load balancer.

History Explorer

Hawk history explorer now includes off-line analysis capabilities.

Resource Agents

Resource agents got multiple updates, including a resource agent to handle SCSI reservations

Make sure to also review the release notes for the base product, SUSE Linux Enterprise Server 12 SP2 which are published at https://www.suse.com/releasenotes/x86_64/SUSE-SLES/12-SP2/.

To find out what is new in the Geo clustering option for the SUSE Linux Enterprise High Availability Extension 12 SP2, see https://www.suse.com/releasenotes/x86_64/SLE-HA/12-SP2-GEO/.

2.1 Documentation for SLE HA 12 SP2 and SLE HA GEO 12 SP2

The documentation for this product has been extended. Some manuals are only available online.

The new Installation and Setup Quick Start guides you through the setup of a very basic two-node cluster.

The Geo Clustering Quick Start explains how to set up an example scenario with a two-site Geo cluster, one arbitrator, and data replication via DRBD.

Both Quick Starts are available on the installation media and online.

The comprehensive Administration Guide has been removed from the installation media, but is available online. Find the complete documentation for this product at https://www.suse.com/documentation/sle-ha-12/ (https://www.suse.com/documentation/sle-ha-12/).

3 Cluster

3.1 Pacemaker Can Trigger Action Based on Event (Alert Agent)

As with resource agents, the cluster calls an external program, an "alert agent", to handle alerts. The cluster passes information about the event to the agent via environment variables. Agents can do anything desired with this information, for example, they can send an e-mail, log to a file, or update a monitoring system.

3.2 AWS Detection When Bootstrapping

Multicast is not available for clusters running on Amazon Web Services.

The ha-cluster-bootstrap scripts now detect if a node is an AWS machine. In that case, the cluster is automatically configured for unicast communication.

3.3 Bootstrap Script Now Allows Unicast Configuration

It is now possible to bootstrap a cluster with unicast instead of multicast. To configure unicast as transport protocol for cluster communication, use:

ha-cluster-init -u

4 High-Availability Tools

4.1 Hawk 2 Replaces Hawk 1 as the Default Version of Hawk for Upgrades

In SLEHA 12 SP1, Hawk 2 already was the default for new installations. However, when upgrading from a previous version of SLEHA, Hawk 1 would be used.

In SLEHA 12 SP2, Hawk 2 replaces Hawk 1 even for system upgrades.

4.2 Hawk: Showing Configuration Text

For configuring ACL rules, it can be helpful to be able to view the text configuration directly in Hawk, as well as the XML format configuration.

The Edit Configuration page now has subpages displaying the crmsh configuration and the raw XML configuration.

4.3 Hawk2: Batch Mode Replaces Simulator

With the previous Simulator, it was not possible to see a summary of changes included in the simulation or to apply the changes to the live configuration.

The new Batch Mode simulation interface of Hawk2 shows the configuration differences compared with the live configuration as well as any simulated events.

When enabling Batch Mode, a control panel appears at the top of the Web interface, allowing you to inject simulator events. In this mode, the simulator runs on any configuration changes or event injections.

You can view the detailed summary of the current simulation and see the list of changes that have been made since entering batch mode.

You can either apply the simulated changes to the cluster configuration or cancel them.

4.4 Hawk: Editing Utilization Attributes for Nodes and Resources

In the past, Hawk displayed utilization attributes (defining a node's capacity) and the current capacity consumed by resources running on the node. However, editing utilization attributes had to be done via the command line.

Now Hawk allows you to edit utilization attributes for both for nodes and resources: You can define the capacity a certain node provides and the capacity a certain resource requires.

4.5 Hawk2: Wizards for Configuring Fencing Resources

Configuring fencing is crucial for a fully functional cluster.

Hawk2 now has a wizard that allows configuring fencing with SBD.

4.6 Hawk2: Improved Resource Editing Controls

Some operations were not available from the Hawk2 interface, such as renaming resources.

You can now rename resources directly from the Hawk2 interface. In addition, the following operations are now also available for groups:

  • Rearranging the children of a group by dragging the handle next to the name

  • Removing a child from a group

  • Adding an existing child to a group

  • Creating a new primitive as a child in a group

4.7 IPv6 Support in ldirectord

Previously, ldirectord did not support HTTP checks for IPv6.

This issue was fixed by adding the packages perl-Net-INET6Glue and perl-IO-Socket-IP as dependencies to ldirectord.

4.8 Upgrade of HAProxy to Version 1.6

HAProxy 1.6 has a lot of new features and significantly improves performance over 1.5.

New features in HAProxy 1.6 include:

  • Simpler handling of multiple configuration files

  • Support for quotes and environment variables in the configuration

  • A significant reduction of the memory usage thanks to a new dynamic buffer allocator

  • Notifications over e-mail

  • Server state keeping across reloads

  • Dynamic DNS-based server address resolution

  • Use of variables in the configuration to manipulate samples

  • Request body buffering and analysis

  • Support for two third-party device identification products (DeviceAtlas and 51Degrees)

  • A lot of new sample converters including arithmetic operators and table lookups

  • TLS ticket secret sharing between nodes

  • TLS SNI to the server

  • Full tables replication between peers

  • The ability to instruct the kernel to quickly kill dead connections

  • Support for Linux namespaces

  • Many other less visible new features

The performance has also been improved a lot with:

  • Support for server connection multiplexing

  • Much faster and cheaper HTTP compression via libslz

  • The addition of a pattern cache to speed up certain expensive ACLs

The great flexibility offered by this version will allow many users to significantly simplify their configurations. Some users will notice a huge performance boost after they enable the features designed for them.

4.9 Hawk 1 Was Dropped

Hawk 1 lacks support for new features in Pacemaker and its look and feel does not match that of other SUSE products.

Hawk 1 has been dropped and is completely replaced by Hawk 2.

4.10 Filter Operators for crm configure show

With Pacemaker remote nodes, it is possible to have a node and a resource with the same name. In previous versions SUSE Linux Enterprise High Availability Extension, crm configure show could not filter for nodes only or resources only.

crm configure show now supports the operators and and or which allow combining name and type filters. To show only the node webui, use:

crm configure show type:node and webui

To show all location or colocation constraints, use:

crm configure show type:location or type:colocation

4.11 crmsh configure load Now Has a Command push

Sometimes, it is desirable to replace a configuration completely.

Using the command crm configure load push to add and remove configuration elements in a single command. For example, use:

crm configure load push <new-configuration>

4.12 Relax-and-Recover Support for UEFI

In past versions, Relax-and-Recover (Rear) did not support disaster recovery on UEFI systems.

SLEHA 12 SP2 ships with Relax-and-Recover 1.18 and the new helper tool ebiso to allow for disaster recovery on UEFI systems.

ebiso can be used to make a UEFI-bootable Relax-and-Recover recovery system ISO image.

To set this up, install the package ebiso and add the following line to /etc/rear/local.conf:

ISO_MKISOFS_BIN=/usr/bin/ebiso

5 Resources and Resource Agents

5.1 DRBD 9 Automatic Resource Promotion

Auto-Promotion is enabled as a tech preview to help customers to work with the new capabilities of DRBD9. This feature might be fully supported in future version.

5.2 DRBD 9-Support for Resource Agent ocf:linbit:drbd

So far, the resource agent ocf:linbit:drbd could only be used with DRBD 8.

DRBD 9 now supports the resource agent ocf:linbit:drbd. You can either continue to use this resource agent to control DRBD or instead switch to file system resources that can promote the underlying DRBD device on demand, using the auto promote feature of DRBD 9.

6 Storage

6.1 Converting Metadata to the DRBD 9 Format When Migrating

Between DRBD 8 (shipped with SLE HA 12 SP1) and DRBD 9 (shipped with SLE HA 12 SP2), the metadata format has changed. DRBD 9 does not automatically convert previous metadata files to the new format.

After migrating to 12 SP2 and before starting DRBD, convert the DRBD metadata to the version 9 format manually. To do so, use:

drbdadm create-md "RESOURCE"

6.2 DRBD 9 Was Added

SLEHA 12 SP2 now ships with DRBD 9, the successor to DRBD 8.

With DRBD 9, SUSE supports the same use cases that were also supported with DRBD 8. Use cases beyond that, such as setups with more than 2 nodes, are not supported.

7 Support Statement for SUSE Linux Enterprise High Availability Extension 12 SP2

Support requires an appropriate subscription from SUSE. For more information, see http://www.suse.com/products/server/.

A Geo Clustering for SUSE Linux Enterprise High Availability Extension subscription is needed to receive support and maintenance to run geographical clustering scenarios, including manual and automated setups.

Support for the DRBD storage replication is independent of the cluster scenario and included as part of the SUSE Linux Enterprise High Availability Extension product and does not require the addition of a Geo Clustering for SUSE Linux Enterprise High Availability Extension subscription.

General Support Statement

The following definitions apply:

  • L1: Installation and problem determination - technical support designed to provide compatibility information, installation and configuration assistance, usage support, on-going maintenance and basic troubleshooting. Level 1 Support is not intended to correct product defect errors.

  • L2: Reproduction of problem isolation - technical support designed to duplicate customer problems, isolate problem areas and potential issues, and provide resolution for problems not resolved by Level 1 Support.

  • L3: Code Debugging and problem resolution - technical support designed to resolve complex problems by engaging engineering in patch provision, resolution of product defects which have been identified by Level 2 Support.

SUSE will only support the usage of original (unchanged or not recompiled) packages.

8 How to Obtain Source Code

This SUSE product includes materials licensed to SUSE under the GNU General Public License (GPL). The GPL requires SUSE to provide the source code that corresponds to the GPL-licensed material. The source code is available for download at http://www.suse.com/download-linux/source-code.html. Also, for up to three years after distribution of the SUSE product, upon request, SUSE will mail a copy of the source code. Requests should be sent by e-mail to mailto:sle_source_request@suse.com or as otherwise instructed at http://www.suse.com/download-linux/source-code.html. SUSE may charge a reasonable fee to recover distribution costs.

9 More Information and Feedback

  • Read the READMEs on the CDs.

  • Get detailed changelog information about a particular package from the RPM (where FILENAME is the name of the RPM):

    rpm --changelog -qp FILENAME.rpm
  • Check the ChangeLog file in the top level of CD1 for a chronological log of all changes made to the updated packages.

  • Find more information in the docu directory of first medium of the SUSE Linux Enterprise High Availability Extension media. This directory includes a PDF version of the High Availability Guide.

  • http://www.suse.com/documentation/ contains additional or updated documentation for SUSE Linux Enterprise High Availability Extension 12 SP2.

  • Visit http://www.suse.com/products/ for the latest product news from SUSE and http://www.suse.com/download-linux/source-code.html for additional information on the source code of SUSE Linux Enterprise products.

Copyright © 2010- 2016 SUSE LLC.

Thanks for using SUSE Linux Enterprise High Availability Extension in your business.

The SUSE Linux Enterprise High Availability Extension Team.

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