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B4HANA HA

ARCHITECTURE

 

ASCS HA Auto Failover – Clustering

 

ASCS                                                                                        ERS

ascsserver – 10.0.1.106                                                        ersserver – 10.0.1.229

VIP – 10.2.0.1                                                                     VIP   – 10.2.0.1

Virtual hostname – haascs                                                    Virtual hostname – haers

 

HANA HA Auto Failover – Clustering

 

HANA NODE1                                                                      HANA NODE2

Hanaha1 – 10.0.1.78                                                              Hanaha2 – 10.0.1.225

VIP – 10.2.0.3

Virtual hostname – hanaha

 

Amazon EC2 – Amazon Elastic Compute Cloud (Amazon EC2) provides scalable computing capacity in the Amazon Web Services (AWS) cloud. Using Amazon EC2 eliminates your need to invest in hardware up front, so you can develop and deploy applications faster. You can use Amazon EC2 to launch as many or as few virtual servers as you need, configure security and networking, and manage storage. Amazon EC2 enables you to scale up or down to handle changes in requirements or spikes in popularity, reducing your need to forecast traffic.

SUSE LINUX Community AMI, Launch 5 instances – PAS, ASCS and ERS and 2 HANA instances.

suse-sles-sap-12-sp3-byos-v20180706-hvm-ssd-x86_64 – ami-2c693f54

 

SUSE Linux Enterprise Server for SAP Applications 12 SP3 for BYOS (HVM, 64-bit, SSD-Backed)

 

Creation of EC2 instances

 

Amazon EFS – Amazon Elastic File System (Amazon EFS) provides simple, scalable file storage for use with Amazon EC2 instances in the AWS Cloud. Amazon EFS is easy to use and offers a simple interface that allows you to create and configure file systems quickly and easily. With Amazon EFS, storage capacity is elastic, growing and shrinking automatically as we add and remove files, so our applications have the storage they need, when they need it. As EFS is a file storage it can be mounted across several EC2 instances.

 

Creation of Elastic file system

Amazon Elastic File System (Amazon EFS) provides simple, scalable file storage for use with Amazon EC2 instances in the AWS Cloud. Amazon EFS is easy to use and offers a simple interface that allows you to create and configure file systems quickly and easily. With Amazon EFS, storage capacity is elastic, growing and shrinking automatically as we add and remove files, so our applications have the storage they need, when they need it. As EFS is a file storage it can be mounted across several EC2 instances.

Mounting EFS to EC2 Instances

 

Create Directory on the EC2 instances

Create /etc/fstab entry

ASCS/ERS filesystem

PAS filesystem

HANAHA1 filesystem

HANAHA2

 

Change the hostname of the EC2 Instances

ASCS

sudo hostnamectl set-hostname ascsserver

ERS

Sudo hostnamectl set-hostname ersserver

HANAHA1

Sudo hostnamectl set-hostname hanaha1

HANAHA2

Sudo hostnamectl set-hostname hanaha2

PAS

Sudo hostnamectl set-hostname passerver

Tagging the EC2 instances

Amazon Web Services (AWS) allows customers to assign metadata to their AWS resources in the form of tags. Each tag is a simple label consisting of a customer-defined key and an optional value that can make it easier to manage, search for, and filter resources.

The EC2 instances will have host names which are automatically generated.

The SLES agents will have to be able to identify the EC2 instances in the correct way.

ASCS

 

In the same way do it for ERS,PAS,HANAHA1 and HANAHA2

Creating an AWS CLI Profile on EC2 Instances

The SLES agents use the AWS Command Line Interface (CLI). They will use an AWS CLI profile which needs to be created for the root account root on both instances. The SUSE resources require a profile which creates output in the text format. The name of the profile is arbitrary.

ASCS

In the same way do it for ERS,PAS,HANAHA1 and HANAHA2

Disable the Source/Destination Check for the Cluster Instances

** Do this on all the server**

The following command needs to be executed one time for both EC2 instances, which are supposed to receive traffic from the Overlay IP address.

 

Overlay IP Addresses

Add VIP on Route table

add the virtual ip to the network interface of ASCS, ERS and HANAHA1

Add the Service IP Address for your ASCS Service

add the overlay ip to ascs, ers and hanaha1

 

 

Configure http Proxies

** Do this on all the server**

 

export http_proxy=10.*.*.*:80

export https_proxy=10.*.*.*:443

export NO_PROXY=169.254.169.254

Permit Root Login in SSH and Change Root Password

 

SAP Installation

 

 

ASCS INSTALLATION

 

./sapinst   SAPINST_USE_HOSTNAME=haascsIS_HOST_LOCAL_USING_STRING_COMPARE=true

 

 

 

 

ASCS installation got Completed.

ERS INSTALLATION

./sapinst  SAPINST_USE_HOSTNAME=haers IS_HOST_LOCAL_USING_STRING_COMPARE=true

ERS Installation got completed

Post steps for ASCS and ERS

 

Stopping ASCS and ERS

 

Maintaining sapservices

Ensure that the file /usr/sap/sapservices holds both entries (ASCS+ERS) on both cluster nodes.

Integrating the Cluster Framework using the sap_suse_cluster_connector Package

For the ERS and ASCS instance edit the instance profile files B4H_ASCS10_haascs and B4H_ERS20_haers in the profile directory /usr/sap/B4H/SYS/profile/

 ASCS profile

 

ERS profile

 

Start ASCS and ERS

 

Add the user b4hadm to the Unix user group haclient

 

DB INSTANCE INSTALLATION

 

INSTALL DB INSTANCE ON HANAHA1

 

./sapinst  SAPINST_USE_HOSTNAME=hanaha

IS_HOST_LOCAL_USING_STRING_COMPARE=true

 

 

DB Instance Installation Completed.

 

PAS INSTALLATION

 

./sapinst

PAS installation completed.

 

ASCS/ERS CLUSTER CREATION

ASCS

 

ERS

ssh ersserver from ascsserver

ssh ascsserver from ersserver

ASCS

 ha-cluster-init

ERS

 

Preparing the Cluster for adding the Resources

Put cluster on maintenance

As user root

crm configure property maintenance-mode=”true”

 

**NOTE**

Stop all SAP instances

Remove the (manual added) IP addresses on the cluster nodes

Unmount the file systems which will be controlled by the cluster

 

Configure AWS specific Settings

 

Configuration of AWS specific Stonith Resource

The EC2 tag pacemaker entry needs to match the tag chosen for the EC2 instances. The value for this tag will contain the host name.

Configure the Resources for the ASCS

Filesystem Primitives

VIP Primitives

SAP instance

The name of the AWS CLI profile will have to match the previously configured AWS profile.

 

Group the resources for ASCS

 

Configure the Resources for the ERS

Filesystem Primitives

VIP Primitives

SAP Instance

The name of the AWS CLI profile will have to match the previously configured AWS profile.

 

Group the resources for ERS

Configure the Colocation Constraints between ASCS and ERS

The constraints between the ASCS and ERS instance are needed to define that the ASCS instance should start-up exactly on the cluster node running the ERS instance after a failure.

crm configure property maintenance-mode=”false”

 

SAP HANA SYSTEM REPLICATION CONFIGURATION

 

HANAHA1(primary)                                                                HANAHA2(secondary)

 

Hana System Replication is configured.

 

HANA CLUSTER CONFIGURATION

 

HANAHA1

HANAHA2

ssh hanaha2 from hanaha1

ssh hanaha1 from hanaha2

 

 

 

HANAHA1

ha-cluster-init -u

HANAHA2

Preparing the Cluster for adding the Resources

Put cluster on maintenance

As user root

crm configure property maintenance-mode=”true”

Configure AWS specific Settings

Configuration of AWS specific Stonith Resource

The EC2 tag pacemaker entry needs to match the tag chosen for the EC2 instances. The value for this tag will contain the host name.

 

The name of the AWS CLI profile will have to match the previously configured AWS profile.

 

Configure the Resources for HANA

VIP Primitives

HANA instance

HANA topology

Configure the Colocation Constraints for HANA

crm configure property maintenance-mode=”false”

 

 

 

This completes the BW4HANA Application in which ASCS/ERS is on HA and Database Hana is also highly available with hana system replication configured.

 

 

 

 

 

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