SUSE Best Practices High Availability Cluster - Setup Guide

1 SUSE Best PracticesSAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup GuideSUSE linux Enterprise Server for SAP Applications 15 Fabian Herschel, Distinguished Architect SAP, SUSEB ernd Schubert, SAP Solution Architect, SUSE1 SAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup GuideSUSE linux Enterprise Server for SAP Applications is optimized in variousways for SAP* applications. This document explains how to deploy an S/4 HANA Enqueue Replication 2 High Availability Cluster solution. It is basedon SUSE linux Enterprise Server for SAP Applications 15. The concept how-ever can also be used with newer service packs of SUSE linux EnterpriseServer for SAP : Documents published as part of the SUSE Best Practices se-ries have been contributed voluntarily by SUSE employees and third are meant to serve as examples of how particular actions can be per-formed.

2 They have been compiled with utmost attention to detail. Howev-er, this does not guarantee complete accuracy. SUSE cannot verify that ac-tions described in these documents do what is claimed or whether actionsdescribed have unintended consequences. SUSE LLC, its affiliates, the au-thors, and the translators may not be held liable for possible errors or theconsequences Date: 2020-02-25 Contents1 About This Guide42 Scope of This Document63 Overview64 SAP Installation165 Implementing the Cluster246 Administration297 Multi-Node Cluster Setups for an SAP S/4 HANA358 References439 Appendix462 SAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup Guide10 Legal Notice503 SAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup Guide1 About This linux Enterprise Server for SAP Applications is the optimal platform to run SAP* appli-cations with high Availability .

3 Together with a redundant layout of the technical infrastructure,single points of failure can be * Business Suite is a sophisticated application platform for large enterprises and mid-sizecompanies. Many critical business environments require the highest possible SAP* described Cluster solution can be used for SAP* SAP S/4 HANA ABAP S/4 HANA ABAP Platform is a common stack of middleware functionality used to supportSAP business applications. The SAP Enqueue Replication Server 2 constitutes application levelredundancy for one of the most crucial components of the SAP S/4 HANA ABAP Platform stack,the enqueue service. An optimal effect of the enqueue replication mechanism can be achievedwhen combining the application level redundancy with a high Availability Cluster solution, asprovided for example by SUSE linux Enterprise Server for SAP Applications. Over several yearsof productive operations, the components mentioned have proven their maturity for customersof different sizes and here described HA Setup is based on Cluster -controlled filesystems for the SAP centralservices working directories.

4 This Setup with Cluster -controlled filesystem resources has beenused in former HA certifications. It still is supported. For deploying new HA clusters we rec-ommend using the so called simple-mount Setup , described in "SAP S/4 HANA - EnqueueReplication 2 High Availability Cluster With Simple Mount - Setup Guide " ( ). Documentation and ResourcesSeveral chapters in this document contain links to additional documentation resources that areeither available on the system or on the the latest product documentation updates, see whitepapers, guides and best Practices documents referring to SUSE linux Enterprise Serv-er and SAP can be found and downloaded at the SUSE Best Practices Web page: S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup GuideHere you can access guides for SAP HANA system replication automation and High Availability (HA) scenarios for SAP NetWeaver and SAP resources, such as customer references, brochures or flyers, can be found at the SUSEL inux Enterprise Server for SAP Applications resource library.

5 But not least, there are manual pages shipped with the deliver urgent smaller fixes and important information in a timely manner, the TechnicalInformation Document (TID) for this document will be updated, maintained and published ata higher frequency:SAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup Guide - Errata( )In addition to this Guide , check the SUSE SAP Best Practice Guide Errata for other solutions( ). feedback channels are available:Bugs and Enhancement RequestsFor services and support options available for your product, refer to report bugs for a product component, go to requests, log in,and select Submit New SR (Service Request).MailFor feedback on the documentation of this product, you can send a mail to Make sure to include the document title,the product version and the publication date of the documentation. To report errors orsuggest enhancements, provide a concise description of the problem and refer to the re-spective section number and page (or URL).

6 5 SAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup Guide2 Scope of This DocumentThe document at hand explains how to:Plan a SUSE linux Enterprise High Availability platform for SAP S/4 HANA ABAP Platform,including SAP Enqueue Replication Server up a linux high Availability platform and perform a basic SAP S/4 HANA ABAP Platforminstallation including SAP Enqueue Replication Server 2 on SUSE linux the high Availability Cluster with the SAP control framework via sap-suse-clus-ter-connector version 3, as certified by Guide implements the Cluster architecture for enqueue replication version 2. For SAPS/4 HANA ABAP Platform versions 1809 or newer enqueue replication version 2 is Guide focuses on the high Availability of the central services. For SAP HANA system replica-tion consult the guides for the performance-optimized or cost-optimized scenario (see Section , Additional Documentation and Resources ).

7 3 OverviewThis document describes setting up a pacemaker Cluster using SUSE linux Enterprise Server forSAP Applications 15 for the Enqueue Replication scenario. The focus is on matching the SAP S/4-HA-CLU certification specifications and goals. For the Setup described in this document, twonodes are used for the ASCS central services instance and ERS replicated enqueue instance. Thesetwo nodes are controlled by the SUSE linux Enterprise High Availability Cluster . A third nodeis used for running the database and PAS and AAS application server instances. An additionalfourth node is used as NFS goals for the Setup include:Integration of the Cluster with the SAP start framework sapstartsrv to ensure that mainte-nance procedures do not break the Cluster kernel Switch (RKS) S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup GuideStandard SAP installation to improve support of automated HA maintenance mode for SAP resources by implementing supportof SAP HACheckMaintenanceMode and of more than two Cluster nodes for ASCS and ERS instances updated certification SAP S/4-HA-CLU redefines some of the test procedures and de-scribes new expectations how the Cluster should behave in special conditions.

8 These changesallowed to improve the Cluster architecture and to design it for easier usage and SAP resources are located on a central NFS SAP instances themselves are installed on a shared disk to allow for switching over the lesystems for proper functionality. A shared disk Setup also allows using the SBD for the clusterfencing mechanism to Previous Cluster ArchitecturesThe described new concept differs from the old stack that used a multi-state the new certification there is a switch to a simpler model with primitives. This means:on one machine there is the ASCS instance with its own resources and on the other machinethere is the ERS instance with its own SAP S/4 HANA the new concept implies that, after a resource failure, the ASCS doesnot need to be started at the ERS side. The new enqueue architecture is also named Systems or More for ASCS, ERS, Database and AdditionalSAP InstancesThis document describes the installation of a distributed SAP system on three and more this Setup , only two systems reside inside the Cluster .

9 The database and SAP dialog instancescan be added to the Cluster either by adding more nodes to the Cluster or by installing thedatabase on either of the existing nodes. However, it is recommended to install the database ona separate Cluster . The Cluster configuration for three and more nodes is described at the end ofthis document. The number of nodes within one Cluster should be either two or an odd : Because the Setup at hand focuses on the SAP S/4-HA-CLU certification, the clusterdetailed in this Guide only manages the SAP instances ASCS and S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup GuideIf your database is SAP HANA, we recommend setting up the performance-optimized systemreplication scenario using the automation solution SAPHanaSR. The SAPHanaSR automationshould be set up in an own two-node Cluster . The Setup is described in a separate best practicesdocument available from the SUSE Best Practices Web ANode BenqueuereplicationVIPascspacemakeractiv e/activeNode CSAP (HA1)DatabasePAS, AASSAP (HA1)ERSSAP (HA1)ASCSVIPersVIPdbVIPaasAASVIPpasASCSE RSDBPASFIGURE 1: THREE SYSTEMS FOR THE CERTIFICATION SETUPCLUSTERED MACHINES TWO-NODE SCENARIOone machine (valuga11) for ASCSH ostname: sapen2asone machine (valuga12) for ERSH ostname: sapen2erNON-CLUSTERED MACHINEone machine (valuga01) for DB and as application serverHostname: sapen2dbHostname: sapen2d1 Hostname.

10 Sapen2d28 SAP S/4 HANA - Enqueue Replication 2 High Availability Cluster - Setup Availability for the DatabaseDepending on your needs, you can increase the Availability of the database, if your database isnot already highly available by HANA System ReplicationA perfect enhancement of the three-node scenario described in this document is to implementan SAP HANA system replication (SR) ANode BenqueuereplicationVIPascspacemakeractiv e/activeNode CSAP (HA1)HANA primaryPASSAP (HA1)ERSSAP (HA1)ASCSVIPersVIPdbVIPpasASCSERSHANAPAS Node DSAP (HA1)HANA secondaryAASVIPaasAASHANA pacemakeractive/activesystemreplicationF IGURE 2: ONE Cluster FOR CENTRAL SERVICES, ONE FOR SAP HANA SRTABLE 1: THE FOLLOWING OS/DATABASE COMBINATIONS ARE EXAMPLES FOR THIS SCENARIOSUSE linux Enterprise Server for SAP Applications 15 Intel X86_64 SAP HANA DATABASE for SAP S/4 HANA ABAP Platform on linux on AMD64/Intel 64.