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We Built HANA Multitarget to be a Game-changer

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HANA Multi-target to be a Game-changer

We Built HANA Multitarget to be a Game-changer

On behalf of the SIOS engineering team that created the new HANA Multitarget feature in SIOS LifeKeeper for Linux v. 9.7.0, we are proud and excited of our accomplishment. It took an experienced team of software developers months of planning before we even started the implementation. We worked through a number of customer use cases, technical requirements, and an impossible list of interdependencies to create a feature that is both unique and powerful.

An Engineer’s Perspective on the HANA Multitarget Feature

HANA clustering environments are intrinsically complicated. That’s why customers who want to add a third node to their HANA cluster using competing clustering software have to use some pretty complex scripting and continue to script any changes to the cluster in the event of a failover or failback. With these products, after a failover occurs you have to do a lot of manual verification steps to be sure it’s ok to perform a takeover. Unlike those products, LifeKeeper 9.7.0 accesses detailed information about all the HANA nodes in your cluster that make it a much more stable and reliable HA environment. For example, it can determine which nodes are available and capable of a takeover and can also see if there was data loss after the failover occurred. This is very important, especially if multiple nodes have failed.

The complexity of managing both failover and replication reliably in a multinode environment increases exponentially with every added node. For example, how will the clustering software choose which node to failover to? With data stored in three nearly identical locations, which storage is most current and accurate? How do you guard against a “split brain” scenario where data on different nodes diverge? What should the failover and replication steps be if two nodes fail? Three? We faced the challenge of thinking through the various combinations of failure scenarios and ensuring that SIOS maintained data protection and a reliably failover in each of them.

LifeKeeper monitors the environment at a deeper level than competing products and has stringent requirements for managing failovers. The new 9.7.0 version of LifeKeeper has an enhanced ability to keep track of the HSR hierarchy, and to manage failovers of complex three and four-node HSR clusters to ensure they are fast and highly reliable.

We set out to create the most automated and reliable multitarget clustering environment for HANA in the industry and I believe we succeeded.

Why HANA Multitaget Provides the Most Reliable Clustering Environment

  • We put just as much time into rigorous testing as we put into development to make sure the systems would be as predictable and stable as possible.
    We eliminated an amazing amount of manual steps. There is no comparison to other clustering software. SIOS LifeKeeper is by far the most automated and reliable solution for multitarget clustering.
  • Extensive effort went into research and development. The team worked on multiple design options before settling on the final implementation.
  • After we developed and tested the third-node functionality, we continued our development efforts to support a fourth DR node to give our customers disaster recovery with even more reliability and stability.
  • The entire team really took testing as seriously as possible, and continuously tested the HANA failover and recovery processes themselves during development.
  • Our documentation team also worked hard to create detailed, easy-to-use documentation about the implementation, operation, and management of a HANA multitarget system controlled by LifeKeeper.

We believe the new LifeKeeper HANA Multitarget is a game-changer that gives customers the most automated, reliable failover clustering solution in the industry. Watch a demo of the new feature to see its capabilities.

Contact SIOS today for more information on the HANA Multitarget feature for LifeKeeper.

Reproduced with permission from SIOS

Minimizing Downtime with High Availability

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Minimizing Downtime with High Availability

Minimizing Downtime with High Availability

Downtime has become more costly than ever before for modern businesses. The ITIC 2021 Hourly Cost of Downtime Survey found that in 91% of organizations, one hour of downtime in a business-critical system, database, or application costs an average of more than $300,000, and for 18% of large enterprises, the cost of an hour of downtime exceeds $5 million.

High availability (HA) is an attribute of a system, database, or application that’s designed to operate continuously and reliably for extended periods. The goal of HA is to reduce or eliminate unplanned downtime for critical applications. This is achieved by eliminating single points of failure by incorporating redundant components and other technologies in the design of a business-critical system, database, or application.

SLAs and HA Metrics

Service-level agreements (SLAs) are used by service providers to guarantee that a customer’s business-critical systems, databases, or applications are up and running when the business needs them.

IDC has created an SLA model that defines uptime requirements at five levels as follows:

  • AL4 (Continuous Availability – System Fault Tolerance): No more than 5 minutes and 15 seconds of planned and unplanned downtime per year (99.999% or “five-nines” availability)
  • AL3 (High Availability – Traditional Clustering): No more than 52 minutes and 35 seconds of planned and unplanned downtime per year (99.99% or “four-nines” availability)
  • AL2 (Recovery – Data Replication and Backup): No more than 8 hours, 45 minutes, and 56 seconds of planned and unplanned downtime per year (99.9% or “three-nines” availability)
  • AL1 (Reliability – Hot Swappable Components): No more than 87 hours, 39 minutes, and 29 seconds of planned and unplanned downtime per year (99% or “two-nines” availability)
  • AL0 (Unprotected Servers): No availability or uptime guarantee

 According to ITIC, 89% of surveyed organizations now require “four-nines” availability for their business-critical systems, databases, and applications, and 35% of those organizations further endeavor to achieve “five-nines” availability.

In addition to uptime and availability, two other important HA metrics are Recovery Time Objectives (RTOs) and Recovery Point Objectives (RPOs). RTO is the maximum tolerable duration of any outage and RPO is the maximum amount of data loss that can be tolerated when a failure happens. Unlike RTO and RPO metrics for disaster recovery which are typically defined in hours and days, RTO and RPO metrics for business-critical systems, databases, and applications are often only a few seconds (RTO) and zero (RPO).

HA Clustering

HA clustering typically consists of server nodes, storage, and clustering software.

Traditional Clustering

A traditional, on-premises HA cluster is a group of two or more server nodes connected to shared storage (typically, a storage area network, or SAN) that are configured with the same operating system, databases, and applications (see Figure 1).

Traditional server clustering with shared storage
Figure 1: Traditional server clustering with shared storage

One of the nodes is designated as the primary (or active) node and the other(s) are designated as secondary (or standby) nodes. If the primary node fails, clustering allows a system, database, or application to automatically fail over to one or more secondary nodes and continue operating with minimal disruption. Since the secondary node is connected to the same storage, operation continues with zero data loss.

However, the use of shared storage in the traditional clustering model creates several challenges, including:

  • The shared storage itself is a single point of failure that can potentially take all of the connected nodes in the cluster offline.
  • SAN storage can also be costly and complex to own and manage.
  • Shared storage in the cloud can add significant, unnecessary cost and complexity and some cloud providers don’t even offer a shared storage option.

SANless Clustering

SANless or “shared nothing” clusters (see Figure 2) address the challenges associated with shared storage. In these configurations, every cluster node has its own local storage. Efficient host-based, block-level replication is used to synchronize storage on the cluster nodes, keeping them identical. In the event of a failover, secondary nodes access an identical copy of the storage used by the primary node.

HA clustering with SANless or “shared-nothing” storage
Figure 2: HA clustering with SANless or “shared-nothing” storage

Clustering Software

Clustering software lets you configure your servers as a cluster so that multiple servers can work together to provide HA and prevent data loss. A variety of clustering software solutions are available for Windows, Linux distributions, and various virtual machine hypervisors. However, each of these solutions limits your flexibility and deployment options and introduces various challenges such as technical complexity and expensive licensing.

Don’t Wait for Disaster to Strike

HA is crucial for business-critical systems, databases, and applications. But with the myriad platforms available, complexity ramps up significantly. That’s why an application-aware solution makes so much sense. What you need is a trusted partner who has extensive expertise in high availability—a partner like SIOS, which has the technological know-how to ensure that your business stays up and running.

Don’t wait for an outage or disaster to find out if you have the resiliency your business needs. Schedule a personalized demo today at https://us.sios.com to see what SIOS can do for your business.

Reproduced from SIOS

Introduction To Clusters – Part 1

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Introduction To Clusters – Part 1

Introduction To Clusters – Part 1

What is clustering in the first place?

Clustering technology is a technology that allows you to connect multiple servers to act as a single functional unit.

Types of clustering

You can cluster servers for several purposes. For example, you can combine the processing power of multiple small servers for high performance. You can also distribute processing work to multiple nodes using a load balancer for added efficiency.

High availability (HA) clustering is a process of combining server nodes to protect important applications from downtime and data loss.

Introduction To Clusters
In a traditional shared storage failover cluster, a primary node and secondary or remote node share the same storage.

HA Clustering

High availability (HA) clustering is a mechanism that reduces downtime by eliminating single points of failure (SPOF). In an HA cluster, important applications are run on a primary node which is connected to one or more secondary or remote nodes in a cluster. Clustering software monitors the health of the application, server, and network. In the event of a failure on the primary node, it moves application operations over to a secondary node in a process called a failover, where operation continues.

High Availability

Application high availability is a measure of how much time in a given year an application is available and operational. In general, HA clusters provide 99.99% (Four nines) availability or a little more than 52 minutes of downtime over the course of a given year.

It is important to note that in a traditional HA cluster, all of the cluster nodes are connected to the same shared storage – typically a SAN. In this way, after a failover, the secondary node is accessing the same data as the primary node and operation can continue.

Introduction To Clusters
SANless cluster synchronizes local storage using host-based block level replication.

SANless Clusters

However, many companies prefer to use a SANless cluster for several reasons. First, shared storage represents a critical single point of failure. Second, shared storage is often not an option in public cloud environments. Third, SANs can sometimes impede performance of database applications, such as SQL Server, Oracle, and SAP.

Instead of shared storage, these companies use efficient, host-based, block-level replication to synchronize local storage on all cluster nodes. In the event of a failover, the secondary node is connected to local storage with an identical copy of the primary storage. This not only eliminates the SAN SPOF risk but also enables the addition of fast disk (SSD) to local on-premises storage for cost-efficient high performance. SANless clustering also enables companies to migrate on-premises HA environments to the cloud with minimal effort or disruption of ongoing business processes.

Reproduced from SIOS

Clustering Software for High Availability and Disaster Recovery

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Clustering Software for High Availability and Disaster Recovery

Clustering Software

Clustering Software for High Availability and Disaster Recovery

What is Clustering Software?

Clustering software lets you configure your servers as a grouping or cluster so that multiple servers can work together to provide availability and prevent data loss. Each server maintains the same information – operating systems, applications, and data. If one server fails, another server immediately picks up the workload. IT professionals rely on clustering to eliminate a single point of failure and minimize the risk of downtime. In fact, 86 percent of all organizations are operating their HA applications with some kind of clustering or high availability mechanism in place.[1]

Types of Cluster Management Software

There are a variety of cluster management software solutions available for Windows and Linux distributions. Examples include:

  • Windows Server Failover Clustering (WSFC),
  • SUSE Linux Enterprise High Availability Extension,
  • Red Hat Cluster Suite,
  • Oracle Real Application Clusters (RAC), and
  • SIOS software.

Except for SIOS, these products support a single operating system or require expensive SAN hardware, constraining flexibility and deployment options. Moreover, Linux open-source HA extensions require a high degree of technical skill, creating complexity and reliability issues that challenge most operators.

SIOS products uniquely protect any Windows- or Linux-based application operating in physical, virtual, cloud or hybrid cloud environments and in any combination of site or disaster recovery scenarios. Applications such as SAP and databases, including Oracle, SQL Server, DB2, SAP HANA and many others, benefit from SIOS software. The “out-of-the-box” simplicity, configuration flexibility, reliability, performance, and cost-effectiveness of SIOS products set them apart from other clustering software.

How SIOS Clustering Software Provides High Availability for Windows and Linux Clusters

If you are running a critical application in a Windows or Linux environment, you may want to consider SIOS Technology Corporation’s high availability software clustering products.

In a Windows environment, SIOS DataKeeper Cluster Edition seamlessly integrates with and extends Windows Server Failover Clustering (WSFC) by providing a performance-optimized, host-based data replication mechanism. While WSFC manages the software cluster, SIOS performs the replication to enable disaster protection and ensure zero data loss in cases where shared storage clusters are impossible or impractical, such as in cloud, virtual, and high-performance storage environments.

In a Linux environment, the SIOS Protection Suite for Linux provides a tightly integrated combination of high availability failover clustering, continuous application monitoring, data replication, and configurable recovery policies, protecting your business-critical applications from downtime and disasters.

Whether you are in a Windows or Linux environment, SIOS products free your IT team from the complexity and challenges of computing infrastructures. They provide the intelligence, automation, flexibility, high availability, and ease-of-use IT managers need to protect business-critical applications from downtime or data loss. With over 80,000 licenses sold, SIOS is used by many of the world’s largest companies.

Here is one case study that discusses how a leading Hospital Information Systems (HIS) provider deployed SIOS DataKeeper Cluster Edition to improve high availability and network bandwidth in their Windows cluster environment.

How One HIS Provider Improved RPO and RTO With SIOS DataKeeper Clustering Software

This leading HIS provider has more than 10,000 U.S.-based health care organizations (HCOs) using a variety of its applications, including patient care management, patient self-service, and revenue management. To support these customers, the organization had more than 20 SQL Server clusters located in two geographically dispersed data centers, as well as a few smaller servers and SQL Server log shipping for disaster recovery (DR).

The organization has a large customer base and vast IT infrastructure and needed a solution that could handle heavy network traffic and eliminate network bandwidth problems when replicating data to its DR site. The organization also needed to improve its Recovery Point Objective (RPO) and Recovery Time Objective (RTO) to reduce the volume of data at risk and get IT operations back up and running faster after a disaster or system failure. RPO is the maximum amount of data loss that can be tolerated when a server fails, or a disaster happens. RTO is the maximum tolerable duration of any outage.

To address these challenges, this organization chose SIOS DataKeeper Cluster Edition, which provides seamless integration with WSFC, making it possible to create SANless clusters.

Once SIOS DataKeeper Cluster Edition passed the organization’s stringent POC testing, the IT team deployed the solution in the company’s production environment. The team deployed SIOS across a three-node cluster comprised of two SAN-based nodes in the organization’s primary, on-premises data center and one SANless node in its remote DR site.

The SIOS solution synchronizes replication across the three nodes in the cluster and eliminates the bandwidth issues at the DR site, improving both RPO and RTO and reducing the cost of bandwidth. Today, the organization uses SIOS DataKeeper Cluster Edition to protect their SQL Server environment across more than 18 cluster nodes.

See the full case study to learn more.

How SIOS Clustering Software Works

SIOS software is an essential part of your cluster solution, protecting your choice of Windows or Linux environments in any configuration (or combination) of physical, virtual and cloud (public, private, and hybrid) environments without sacrificing performance or availability.

If you need fast, efficient, replication to transfer data across low-bandwidth local or wide area networks,  SIOS DataKeeper protects business-critical Windows environments, including Microsoft SQL Server, Oracle, SharePoint, Lync, Dynamics, and Hyper-V from downtime and data loss in a physical, virtual, or cloud environment.

SIOS Protection Suite for Linux supports all major Linux distributions, including Red Hat Enterprise Linux, SUSE Linux Enterprise Server, CentOS, and Oracle Linux and accommodates a wide range of storage architectures.

To see how SIOS clustering software works to protect Windows and Linux environments, request a demo or get a free trial.

Learn more about:

SAP clustering
SQL Server clustering
Oracle clustering
Linux clustering

Check out recent blog posts about our clustering products.

References

[1] SIOS in partnership with ActualTech Research, (2018) The State of Application High Availability Survey Report

Reproduced from SIOS

Clustering SAP #ACS And #ERS On #AWS Using Windows Server Failover Clustering

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Clustering SAP #ACS And #ERS On #AWS Using Windows Server Failover Clustering

Clustering SAP #ACS And #ERS On #AWS Using Windows Server Failover Clustering

When ensuring high availability for SAP ASCS and ERS running on Windows Server, the primary cluster solution you will want to use is Windows Server Failover Clustering. However, when doing this in AWS you will quickly discover that there are a few obstacles you need to know how to overcome when deploying this in AWS.

I recently wrote this Step-by-Step guide that was published on the SAP blog that walks you through the entire process. If you have any questions, please leave a comment.