Using SIOS to Protect your Critical Core on AWS

Using SIOS to protect your SAP Critical Core on AWS

The customer challenge

As an enterprise customer you may have to provide a highly available system for more than one application. Each of these applications may have different supported operating systems and databases and therefore dictate which options you can choose for HA. As a result, you as a customer may end-up supporting multiple HA solutions, adding significant complexity and cost.

Consider databases like Microsoft SQL Server, Oracle, IBM DB2, SAP HANA and MaxDB. Each of these databases requires a different high availability method requiring you to invest time and resources to set them up and maintain them properly.

In this blog you will read about the flexibility that SIOS Protection Suite can provide to you to minimize this complexity.

Introduction to SIOS

AWS has been working with SIOS Technology since 2014. They’ re an APN Technology Partner and hold the APN Microsoft Workload Competency as well.

SIOS Protection Suite Software is an out-of-the-box, SAP-certified high availability solution that provides a tightly integrated combination of:

  • Failover clustering,
  • Continuous application monitoring, and
  • Efficient, block-level data replication.

SIOS Protection Suite monitors the entire infrastructure stack and uniquely includes application-specific recovery kits for highly automated configuration and orchestration of failover for business-critical applications including SAP S/4HANA, SAP HANA, SAP Central Services and a variety of infrastructure services. SIOS clusters also provide the flexibility to protect applications in any configuration (or combination) of virtual, physical, private data centers, Amazon Elastic Compute Cloud (Amazon EC2), or a hybrid form of the latter two.

The latest version of SIOS Protection Suite includes intelligent SAP application availability tools and utilities that automate configuration, validate user input, provide application monitoring and ensure that failover automatically complies with application best-practices throughout failover processes.

What SIOS Offers

SIOS provides SAP-certified high availability for SAP S/4 HANA and supports all of the major databases that can be used for SAP, including SAP HANA, Oracle and Microsoft SQL Server. On top of that it also supports SAP NetWeaver application server components such as Enqueue Replication Service that is used in HA configurations.

The SIOS Protection Suite for Linux includes three main components;

  • SIOS LifeKeeper software that manages and monitors all cluster resources and orchestrates switchover or automatic failover if needed.
  • SIOS DataKeeper provides host-based, block-level replication, enabling customers to synchronize local storage on different cluster nodes for SAN-less clustering configuration
  • SIOS Application Recovery Kits (ARKs) which provide application-specific intelligence and automation for SAP HANA and a wide range of other applications, infrastructure components and cloud platforms.
SIOS Architecture overview

The picture shows the key SIOS components such as Lifekeeper, Application Recovery Kits and Datakeeper and how it interacts to provide and application level of awareness.


What are your HA Options?

Since we started this blog with the new HANA Application Recovery Kit let’s look at the options for using SIOS on SUSE and Red Hat Enterprise Linux. On these operating systems SIOS supports the complete SAP stack as depicted in the diagram below. In this scenario, SIOS would manage the S/4 HANA application piece, as well as the HANA System Replication (HSR) at the database level.

HA Overview for SAP on AWS

The picture shows how you can do HA for SAP application servers as well as databases using multiple AWS availabillity zones.

It’s important to note that SIOS supports both SAP Enqueue Replication Server V1 and V2 starting with SIOS Protection Suite for Linux 9.4.0. The following diagram shows a typical HA scenario for ERS V2 — or ENSA2 as it is commonly called.

SIOS HA Scenario

The picture shows the failover process for an SAP central services instance using SIOS Protection Suite.

A 3-Node Cluster configured as follows:

  • SAP ABAP Central Services instance (ASCS) in-service on Node 1
  • SAP Enqueue Replication Service (ERS) in-service on Node 2
  • Lock table replication is in-sync

Process flow:

  1. Node 1 fails.
  2. LifeKeeper starts ASCS instance on Node 3.
  3. ENSAv2 process sends connection request to ERSv2 process and obtains the backup lock table over the network.
  4. Once ENSAv2 rebuilds the lock table, it sends a connection request to the ERSv2 process and resumes lock table replication.
  5. Node 2 fails.
  6. LifeKeeper starts ERSv2 instance on Node 3 and lock table replication resumes; At this point there is no lock table redundancy across cluster nodes. The cluster will remain in this state until one of the two failed nodes comes back online.
  7. Node 2 comes back online.
  8. LifeKeeper automatically relocates ERSv2 to Node 2 and lock table replication resumes.


SIOS also has support for SAP’s MaxDB database as part of its SIOS Protection Suite for Linux (SPS-L). The SIOS MaxDB ARK (sometimes known as the SAP DB Recovery Kit) provides a mechanism for fault resilient protection for MaxDB databases in a Linux environment.

The approach here is to take the MaxDB software, SIOS Protection Suite software and the MaxDB Recovery Kit and install them on two or more servers in a cluster. Once the MaxDB database instance is under SIOS Protection Suite protection, clients connect to the database using an SPS-L protected IP address. The SPS-L protected IP address is usually created separately and a dependency is made between the parent MaxDB resource instance and the child IP address resource. In the event that the MaxDB server fails, SPS-L (in conjunction with the MaxDB Recovery Kit) will first attempt to recover it on the local server. If the local recovery fails, then SPS-L will fail over to the next available node in the cluster.

Oracle Linux

Moving on to another Linux flavor which is of particular interest to Oracle customers is Oracle Enterprise Linux. SIOS also supports this distribution and as SIOS supports both Oracle Database Standard Edition and Enterprise Edition it gives customers the flexibility to choose the distribution that best suits their needs.

SIOS SAP on Oracle HA on AWS

The picture shows how SIOS can deliver an HA capabillity for Oracle without the customer needing to use Oracle’s enterprise edition database software.

Microsoft SQL server

Last but not least SIOS helps Windows users as well with full support for Microsoft SQL Server via SIOS DataKeeper Cluster Edition. DataKeeper can be used with SQL Server Standard Edition to create a SANless HA clustering environment without the need for more costly Microsoft SQL Server Enterprise Edition or Always On Availability Groups.

SIOS and Microsoft SQL Server

The picture shows how SIOS can create a SANLESS HA cluster for Microsoft SQL server running in two AWS Availabillity zones.


Deploying SIOS Protection Suite for Linux into Amazon EC2 can be a partly automated process. For example, the core SIOS Protection Suite software can be deployed into Amazon EC2 using the AWS Quick start for it.

This Quick Start uses AWS CloudFormation templates to deploy SIOS Protection Suite into a Amazon Virtual Private Cloud (Amazon VPC) within a single AWS Region across two Availability Zones. In addition to the core SIOS Protection Suite software, it automates a variety of deployment aspects such as Amazon VPCs, public and private subnets, security groups across AZ’s, internet gateways, and so on.

Additional ARKs can be used to automate the configuration of the protection environment. These ARKs are included in the SIOS Protection Suite and can be chosen, individually installed, and initiated according to the needs of the specific environment. Each environment could differ in the types of resources that require protection and therefore, the specific ARKs required also differ from landscape to landscape. The ARKS are designed to be modular and fully compatible with one another, enabling you to customize the configuration to each environment. Differing elements could include operating systems and databases. After selecting a few options via a wizard-based GUI, the ARKs then deploy themselves automatically, and set-up the protection for the required resources.


If you already are running SAP workloads on AWS or are thinking about moving them to AWS and you have to manage high availability solutions in a heterogeneous environment then the solution that SIOS offers can be worthwhile looking into. It can simplify your administrative procedures and reduce the required skillset of your team thereby saving costs.

You can find SIOS AWS offerings on our marketplace at SIOS.