Clustering Archives - SIOS SANless clusters

How to Protect Applications in Windows Operating System

September 7, 2023 by Jason Aw Leave a Comment

How to Protect Applications in Windows Operating System

To mitigate system downtime and ensure high availability for Windows, IT best practice recommends that you connect two or more servers (or nodes) and use clustering software. High availability clustering software monitors the health of the primary node and initiates recovery actions if it detects an issue. In the event of a failure, the secondary node needs to access the most current versions of data in storage. In traditional clusters, this is achieved by connecting all nodes of the clusters to the same shared storage or by using efficient, cluster-aware replication software to synchronize local storage on all cluster nodes.

The cluster nodes should be separated geographically to protect applications from sitewide and regional disasters.

You have several Windows clustering software options, including Microsoft Windows Server Failover Clustering, SIOS LifeKeeper for Windows, and others.

What is Window Clustering?

In a Windows environment, two or more nodes and shares the same storage. A third node is often configured as a “witness” server that designates the primary server if the connection between nodes is lost. In addition to monitoring the health of the cluster, the nodes work together to collectively provide:[1]

Resource management – Individual nodes provide physical resources such as SAN and network interfaces. The hosted applications are registered as a cluster resource and can configure startup and health dependencies upon other resources.
Failover coordination – Each resource is hosted on a primary node and can be automatically or manually transferred to one or more secondary nodes. Nodes and hosted applications are notified when failover occurs so that they can appropriately react. WSFC works with Microsoft Always On Availability Groups and Always On Failover Clustering to coordinate failover In Microsoft SQL Server environments.

How SIOS DataKeeper Complements WSFC

WSFC requires shared storage to ensure all cluster nodes are accessing the most up-to-date data in the event of a failover. Often, companies use expensive SAN hardware to assure data redundancy. SANs represent a single point of failure risk. And, if you want to run your application in the cloud with the same Windows Server Failover clustering protection, there is no SAN available.

SIOS DataKeeper Cluster Edition seamlessly integrates with and extends WSFC and SQL Server Always On Failover clustering by eliminating the need for shared storage. It provides performance-optimized, host-based replication to synchronize local storage in all cluster nodes, creating a SANless cluster. While WSFC manages the cluster, SIOS DataKeeper performs synchronous or asynchronous replication of the storage giving the standby nodes immediate access to the most current data in the event of a failover. SIOS DataKeeper not only eliminates the cost, complexity, and single-point-of-failure risk of a SAN, but also allows you to use the latest in fast PCIe Flash and SSD in your local storage for performance and protection in a single cost-efficient solution.

With SIOS DataKeeper, you can also balance network bandwidth and CPU utilization for each application.

If fast replication is critical, SIOS DataKeeper can achieve more than 90 percent bandwidth utilization to accelerate data synchronization.
If minimizing network impact is your top priority, SIOS DataKeeper offers integrated compression and bandwidth throttling.

In addition, SIOS DataKeeper’s Target Snapshots feature lets you run point-in-time reports from a secondary node to offload workloads that can impact performance on the primary node. This lets you query and run reports faster and make faster decisions.

Working with WSFC, SIOS DataKeeper Cluster Edition protects business-critical Windows environments, including Microsoft SQL Server, SAP, SharePoint, Lync, Dynamics, and Hyper-V using your choice of industry-standard hardware and local attached storage in a “shared-nothing” or SANless configuration.[2] SIOS DataKeeper also provides high availability and disaster recovery protection for your business-critical applications in cloud environments, such as Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Services without sacrificing performance.

SIOS LifeKeeper for Windows – Protecting Windows Applications Without WSFC

SIOS LifeKeeper for Windows is a tightly integrated clustering solution that combines high availability failover clustering, continuous application monitoring, data replication, and configurable recovery policies to protect your business-critical applications and data from downtime and disasters.

Distributed metadata and notifications

The WSFC service and node’s metadata/status are hosted on each node in the cluster. When changes occur on any node, updated information is automatically replicated to all other nodes.

SIOS LifeKeeper for Windows monitors the health of the application environment, including servers, operating systems, and databases. It can stop and restart an application both locally and on another cluster server at the same site or in another location. When a problem is detected, SIOS LifeKeeper automatically performs the recovery actions and automatically manages cascading and prioritized failovers.

With SIOS LifeKeeper, you can use your choice of SAN or SANless clusters using a wide array of storage devices, including direct-attached storage, iSCSI, Fibre Channel, and more.

Protecting the Widest Range of Applications in the Industry

SIOS provides offerings that support a breadth of applications, operating systems, and infrastructure environments, providing a single solution that can handle all your high availability needs. Here are just a few examples that demonstrate the power of SIOS.

Perth Stadium in Western Australia implemented SIOS DataKeeper with WSFC to provide high availability for their Hyper-V virtual machines.
PayGo (paygoutilities.com), based in the U.S., implemented SIOS DataKeeper with WSFC to provide high availability for SQL Server on AWS.
Toyo Gosei, based in Japan, implemented SIOS DataKeeper with WSFC to provide high availability and disaster recovery for their SAP application on Azure.

For more information on high availability/disaster recovery solutions to support your Windows environment click here [TM(1] .

References

https://www.techopedia.com/definition/24358/windows-clustering

https://searchwindowsserver.techtarget.com/definition/Windows-Server-failover-clustering

https://docs.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/windows-server-failover-clustering-wsfc-with-sql-server?view=sql-server-ver15

[1] https://docs.microsoft.com/en-us/sql/sql-server/failover-clusters/windows/windows-server-failover-clustering-wsfc-with-sql-server?view=sql-server-ver15[2] A shared-nothing architecture (SN) is a distributed-computing architecture in which each update request is satisfied by a single node (processor/memory/storage unit). https://en.wikipedia.org/wiki/Shared-nothing_architecture

Reproduced with permission from SIOS

Clusters for Microsoft Azure High Availability

August 15, 2023 by Jason Aw Leave a Comment

Clusters for Microsoft Azure High Availability

High Availability Clustering Solutions for Microsoft Azure

What is Microsoft Azure Clustering?

Microsoft Azure clustering ensures high availability protection for critical applications running in Azure environments by eliminating single points of failure. In an Azure cluster environment, two or more nodes in Azure are configured in a failover cluster using clustering software. The critical application is run on a primary node in the cluster. If clustering software detects an application operation failure, it orchestrates a failover of the application operation to secondary node(s) in the cluster.

Microsoft Azure High Availability with SIOS DataKeeper

For customers running critical Windows applications in Windows Server Failover Clustering (WSFC) environments, SIOS DataKeeper Cluster Edition is the first Azure certified high availability and disaster recovery solution in the Azure Marketplace. It provides efficient data replication and seamless integration into Windows Server Failover Clustering environments for high availability clusters without the need for costly shared storage. Simply add SIOS DataKeeper to a WSFC environment and it synchronizes local storage using highly efficient block-level replication, making it appear to WSFC as traditional shared storage. IT teams use SIOS DataKeeper to continue to use familiar WSFC in the cloud without the cost and complexity of a SAN or other shared storage.

SIOS LifeKeeper

While cloud providers offer high availability service levels for their hardware, they do not cover software-related downtime. Critical critical applications, databases, and ERPS, such as SQL Server, Oracle Database, SAP, HANA companies need 99.99% uptime at the application and data level using SIOS LifeKeeper. SIOS LifeKeeper for Linux and SIOS LifeKeeper for Windows provide application-aware HA/DR for complex, critical applications in Azure for reliable easy-to-manage clustering environment.

SIOS LifeKeeper for Linux is the only solution that provides a comprehensive range of Linux clustering, protecting applications in SUSE Linux, Red Hat Linux, Oracle Linux, and Rocky Linux clustering environments. SIOS LifeKeeper for Windows provides reliable failover clustering for applications in Windows environments. SIOS LifeKeeper comes with unique SIOS application recovery kits that provide application-specific intelligence to automate configuration and management steps and ensure failovers happen in compliance with application-vendor best practices for maximum efficiency and reliability.

SIOS LifeKeeper is sold as part of the SIOS Protection Suite (for Windows and for Linux), a tightly integrated combination of high availability failover clustering, continuous application monitoring, data replication, and configurable recovery policies. SIOS Protection Suite includes SIOS LifeKeeper clustering software, SIOS DataKeeper replications software, and multiple Application Recovery Kits (ARKs) to protect your business-critical applications and data from downtime and disasters.

Azure Site Recovery Compatibility for High Availability and Disaster Protection

SIOS DataKeeper Cluster Edition is the only high availability solution certified for use with Microsoft Azure Site Recovery for cost-efficient high availability and disaster recovery protection for business-critical applications in Azure.

SIOS DataKeeper provides broad compatibility, enabling customers to protect important applications, including SAP, SQL Server, and Oracle, on Azure. SIOS DataKeeper Cluster Edition provides a simple way to use Windows Server Failover Clustering – including SQL Server Always On Failover Clustering – in a cloud environment. Customers can replicate the cluster to a geographically separated location using Azure Site Recovery for cost-efficient, robust disaster protection. Learn more about SQL Server High Availability in Azure.

Together SIOS DataKeeper and Microsoft Azure Site Recovery enable the only option for local high availability protection along with disaster recovery in a highly flexible and on-demand solution.

Protect Linux Applications in Azure

SIOS Protection Suite for Linux lets you run your business-critical applications in Azure or Azure Stack without sacrificing performance, high availability or disaster protection.

Learn more about SIOS SANless Software for Cloud High Availability.

SIOS is SAP Certified

SIOS Protection Suite is fully SAP-certified for your SAP NetWeaver and SAP HANA, including high availability, data replication, and disaster recovery in an easy, cost-efficient solution that can operate in the cloud, on-premises or in hybrid cloud configurations.

Learn more about SIOS High Availability for SAP on Azure

Read the White Paper: High Performance and High Availability for SAP on Azure
Read the Microsoft White Paper: Microsoft High Availability for SAP HANA database on Azure using SIOS Protection Suite
Learn how Zespri International Protects SAP and SQL Server on Azure using SIOS DataKeeper Cluster Edition

Reproduced with permission from SIOS

High Availability Clustering Software for SAP and SAP HANA

July 31, 2023 by Jason Aw Leave a Comment

High Availability Clustering Software for SAP and SAP HANA

SAP S/4HANA High Availability and Disaster Recovery Solutions

SAP-Certified High Availability for SAP and HANA in Physical, Virtual or Cloud Environments

SIOS LifeKeeper for Linux provides intelligent HA protection for mission-critical SAP S/4HANA environments – on-premises or in the cloud – without the need for specialized skills or the risk inherent in complex, manual scripting. Application-aware availability ensures cluster failover automatically adheres to S/4HANA best practices for fast, reliable continued operation.

System cloning capabilities enable easy deployment of SIOS clusters to protect any application using consistent, predefined settings and integrated best practices.

SIOS LifeKeeper for Linux delivers:

Out-of-the-box high availability for SAP HANA – Meet SLAs for >99.99% availability without specialized expertise
5X faster configuration. Wizard-driven, highly automated configuration and management removes time-consuming, error-prone manual steps.
No specialized knowledge of clustering or underlying application technology required
Validation of user input ensures error-free configuration and management settings
Application hooks provide deep monitoring of SAP S/4HANA services and performance
CLI Cloning (Import/Export configuration) enables easy configuration, and operation of new systems with predefined settings and integrated best practices.

Continuous Monitoring of the Entire SAP Environment

Unlike traditional SAP clustering software that only checks that the server is operational, SIOS software monitors the health of the entire application environment and verifies that SAP and/or HANA is running, file shares and provides superior protection:

Protect your entire SAP stack with high availability clustering, continuous data replication, and disaster recovery functionality
Supports both JAVA and ABAP versions of SAP servers running on Red Hat Enterprise Linux, SUSE Linux Enterprise Server, and other Linux OS environments and accommodates a wide range of storage architectures.
Compatible with your local SSD storage for high performance for a fraction of the cost of traditional clusters
Efficient replication engine minimizes network traffic–without hardware accelerators or compression devices
Saves labor cost by automating data replication tasks using an intuitive management console
AS Application Server or NFS exports are available, databases are mounted and available, and clients are able to connect

Monitoring the Entire SAP Environment

SIOS software actively monitors: servers, operating systems, SAP Primary Application Server (PAS) Instance, ABAP SAP Central Service (ASCS) instance, back-end databases (Oracle, DB2, MaxDB, MySQL and PostgresSQL), the SAP Central Services Instance (SCS), volumes or file systems, file shares or NFS mounts, IP and virtual IP, Enqueue and message servers, and Logical Volumes (LVM).

SIOS LifeKeeper software to build a traditional SAN-based cluster or a SANless cluster by synchronizing local storage on the active SAP Server node (or cloud instance) with. local storage on a standby node using real-time, block-level replication. Replication can operate in either synchronous or asynchronous mode. SANless clusters can be used to support high availability operations in cloud environments.

Automatic Failover

In the event of a failure on the active cluster node, SIOS software moves SAP and/or S/4HANA operation to the standby node. SIOS software lets you configure standby servers that are either local or remote over a LAN or WAN. Real-time storage replication ensures immediate recovery from a local system failure and allows you to create multiple real-time copies through one-to-many replication.

SIOS LifeKeeper can also stop and restart the application both locally and on another cluster server at either the same site or at another geographic location. When the SIOS software detects a problem, it automatically initiates one of three configurable recovery actions that will maximize uptime and protection for applications and data: it may attempt a restart on the same server; switchover to a standby server; or alert a system administrator. It performs both local recovery or complete failover quickly and easily.

The Industry’s Most Comprehensive Disaster Protection for SAP HANA

SIOS software makes disaster recovery testing easy by allowing administrators to move SAP and/or HANA to the DR site for testing and to move it back to the primary site when testing is done. It also lets you leave SAP in service in the primary site while completing DR testing with no impact to your production network by unlocking the target data, bringing it into service on the backup system to verify recovery.

SIOS LifeKeeper for Linux with HANA Multitarget feature provides automated high availability and disaster recovery (HA/DR) protection for HANA databases. It allows you to extend a traditional two-node failover cluster to include additional nodes in DR location(s) without the need for complex scripting or cumbersome administration tasks. Learn more here

Consistent HA Protection for Windows and Linux

SIOS gives you the flexibility to run SAP on a combination of Windows and Linux environments while maintaining consistent high availability protection. For example, SIOS LifeKeeper for Linux to protect SAP application and pair it with SIOS DataKeeper software to protect SAP services in a Windows environment.

Low Total Cost of Ownership

SIOS engaged an independent organization with many years of experience in deploying, supporting, and designing high availability (HA) solutions for SAP S4/HANA to compare SIOS LifeKeeper for Linux with SUSE HAE in a side-by-side test. Testing revealed that SIOS clusters could be implemented five times faster (less than 2 hours for SIOS vs 12 Hours for HAE). Annual maintenance was also faster for SIOS,

SIOS Delivers Significant Savings

Example: A small sized SAP implementation with three production systems with equivalent test environments that are clustered for a total of six clusters could save 18 business days with SIOS. Here’s how:

SIOS saves two days per cluster of implementation time and one day per cluster per year on testing/maintenance and significantly reduce implementation risk.

6 clusters X 2 days implementation	12 days
+ 6 clusters X 1 day per year testing/maintenance	6 days (annually)
	Save 18 Days of IT Time

Reproduced with permission from SIOS

We Built HANA Multitarget to be a Game-changer

April 15, 2023 by Jason Aw Leave a Comment

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

January 29, 2022 by Jason Aw Leave a Comment

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).

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.

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