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Webinar: Optimizing SQL Server Costs in Azure HA/DR Deployments

June 28, 2024 by Jason Aw Leave a Comment

Webinar Optimizing SQL Server Costs in Azure HADR Deployments (1)

Webinar: Optimizing SQL Server Costs in Azure HA/DR Deployments

Register for the On-Demand Webinar

One of the challenges with moving to Azure is keeping monthly costs in check. Several Azure services are offered for SQL Server, but you need to be aware of what services you really need and how these fit into your SQL Server cloud strategy.

In this webinar, we delve into High Availability (HA) and Disaster Recovery (DR) for SQL Server deployments in Azure, focusing on cost-efficient methodologies. The session aims to provide a comprehensive understanding and practical demonstrations of three key technologies: Basic Availability Groups, SQL Server Failover Cluster Instances (FCI) with Azure Shared Disks, and Azure Site Recovery. You will gain insights into each method’s architecture, setup, and operational nuances.

We will specifically emphasize optimizing costs without compromising reliability and performance. The session is structured to benefit both newcomers and seasoned professionals in the field of cloud-based SQL Server deployments. By the end of this session, participants will be equipped with the knowledge to make informed decisions about HA/DR strategies in Azure, ensuring both economic efficiency and robustness in their SQL Server environments.

Reproduced with permission from SIOS

Filed Under: Clustering Simplified Tagged With: disaster recovery, High Availability, SQL

Webinar: Thinking Outside the SAN(Box)

May 14, 2019 by Jason Aw Leave a Comment

Thinking Outside the SAN (Box)

Webinar: Thinking Outside the SAN(Box)

SAN-based clusters can bring SQL performance to its knees. Understand why this happens and how to maintain blazing SQL response times in a high availability cluster environment. Microsoft MVP, Geoff Hiten provides expert advice that could save you time and money in this informative 45 minute recorded webinar.

Register for Webinar: Thinking Outside the SAN(Box)

Filed Under: News and Events Tagged With: High Availability, SQL

Managing a Real-Time Recovery in a Major Cloud Outage

January 19, 2019 by Jason Aw Leave a Comment

Managing a Real-Time Recovery in a Major Cloud Outage

Managing A Real-Time Recovery In A Major Cloud Outage

Disasters happen, making sudden downtime reality. But there are things all customers can do to survive virtually any cloud outage.

Stuff happens. Failures—both large and small—are inevitable. What is not inevitable is extended periods of downtime.

Consider the day the South Central US Region of Microsoft’s Azure cloud experienced a catastrophic failure. A severe thunderstorm led to a cascading series of problems that eventually knocked out an entire data center. In what some have called “The Day the Azure Cloud Fell from the Sky,” most customers were offline, not just for a few seconds or minutes, but for a full day. Some were offline for over two days. While Microsoft has since addressed the many issues that led to the outage, the incident will long be remembered by IT professionals.

That’s the bad news. The good news is: There are things all Azure customers can do to survive virtually any outage. It can be from a single server failing to an entire data center going offline. In fact, Azure customers who implement robust high-availability and/or disaster recovery provisions, complete with real-time data replication and rapid, automatic failover, can expect to experience no data loss, and little or no downtime whenever catastrophe strikes.

See also: Nutanix sees enterprise cloud winning the cloud race

Managing The Cloud Outage

This article examines four options for providing disaster recovery (DR) and high availability (HA) protections in hybrid and purely Azure cloud configurations. Two of the options are specific to the Microsoft SQL Server database, which is a popular application in the Azure cloud; the other two options are application-agnostic. The four options, which can also be used in various combinations, are compared in the table and include:

  • The Azure Site Recovery (ASR) Service
  • SQL Server Failover Cluster Instances with Storage Spaces Direct
  • SQL Server Always On Availability Groups
  • Third-party Failover Clustering Software

RT Insights SIOS_Real-timeRecovery for Cloud Outage_181119

RTO and RPO 101

Before describing the four options, it is necessary to have a basic understanding of the two metrics used to assess the effectiveness of DR and HA provisions: Recovery Time Objective and Recovery Point Objective. Those familiar with RTO and RPO can skip this section.

RTO is the maximum tolerable duration of an outage. Online transaction processing applications generally have the lowest RTOs, and those that are mission-critical often have an RTO of only a few seconds. RPO is the maximum period during which data loss can be tolerated. If no data loss is tolerable, then the RPO is zero.

The RTO will normally determine the type of HA and/or DR protection needed. Low recovery times usually demand robust HA provisions that protect against routine system and software failures, while longer RTOs can be satisfied with basic DR provisions designed to protect against more widespread, but far less frequent disasters.

The data replication used with HA and DR provisions can create the need for a potential tradeoff between RTO and RPO. In a low-latency LAN environment, where replication can be synchronous, the primary and secondary datasets can be updated concurrently. This enables full recoveries to occur automatically and in real-time, making it possible to satisfy the most demanding recovery time and recovery point objectives (a few seconds and zero, respectively) with no tradeoff necessary.

Across the WAN, by contrast, forcing the primary to wait for the secondary to confirm the completion of updates for every transaction would adversely impact on performance. For this reason, data replication in the WAN is usually asynchronous. This can create a tradeoff between accommodating RTO and RPO that normally results in an increase in recovery times. Here’s why: To satisfy an RPO of zero, manual processes are needed to ensure all data (e.g. from a transaction log) has been fully replicated on the secondary before the failover can occur This extra effort lengthens the recovery time, which is why such configurations are often used for DR and not HA.

Azure Site Recovery (ASR) Service

ASR is Azure’s DR-as-a-service (DRaaS) offering. ASR replicates both physical and virtual machines to other Azure sites, potentially in other regions, or from on-premises instances to the Azure cloud. The service delivers a reasonably rapid recovery from system and site outages, and also facilitates planned maintenance by eliminating downtime during rolling software upgrades.

Like all DRaaS offerings, ASR has some limitations, the most serious being the inability to automatically detect and failover from many failures that cause application-level downtime. Of course, this is why the service is characterized as being for DR and not for HA.

With ASR, recovery times are typically 3-4 minutes depending, of course, on how quickly administrators are able to manually detect and respond to a problem. As described above, the need for asynchronous data replication across the WAN can further increase recovery times for applications with an RPO of zero.

SQL Server Failover Cluster Instance with Storage Spaces Direct

SQL Server offers two of its own HA/DR options: Failover Cluster Instances (discussed here) and Always On Availability Groups (discussed next).

FCIs afford two advantages: The feature is available in the less expensive Standard Edition of SQL Server, and it does not depend on having shared storage like traditional HA clusters do. This latter advantage is important because shared storage is simply not available in the cloud—from Microsoft or any other cloud service provider.

A popular choice for storage in the Azure cloud is Storage Spaces Direct (S2D), which supports a wide range of applications, and its support for SQL Server protects the entire instance and not just the database. A major disadvantage of S2D is that the servers must reside within a single data center, making this option suitable for some HA needs but not for DR. For multi-site HA and DR protections, the requisite data replication will need to be provided by either log shipping or a third-party failover clustering solution.

SQL Server Always On Availability Groups

While Always On Availability Groups is SQL Server’s most capable offering for both HA and DR, it requires licensing the more expensive Enterprise Edition. This option is able to deliver a recovery time of 5-10 seconds and a recovery point of seconds or less. It also offers readable secondaries for querying the databases (with appropriate licensing), and places no restrictions on the size of the database or the number of secondary instances.

An Always On Availability Groups configuration that provides both HA and DR protections consists of a three-node arrangement with two nodes in a single Availability Set or Zone, and the third in a separate Azure Region. One notable limitation is that only the database is replicated and not the entire SQL instance, which must be protected by some other means.

In addition to being cost-prohibitive for some database applications, this approach has another disadvantage. Being application-specific requires IT departments to implement other HA and DR provisions for all other applications. The use of multiple HA/DR solutions can substantially increase complexity and costs (for licensing, training, implementation and ongoing operations), making this another reason why organizations increasingly prefer using application-agnostic third-party solutions.

Third-party Failover Clustering Software

With its application-agnostic and platform-agnostic design, failover clustering software is able to provide a complete HA and DR solution for virtually all applications in private, public and hybrid cloud environments. This includes for both Windows and Linux.

Being application-agnostic eliminates the need for having different HA/DR provisions for different applications. Being platform-agnostic makes it possible to leverage various capabilities and services in the Azure cloud, including Fault Domains, Availability Sets and Zones, Region Pairs, and Azure Site Recovery.

As complete solutions, the software includes, at a minimum, real-time data replication, continuous monitoring capable of detecting failures at the application level, and configurable policies for failover and failback. Most solutions also offer a variety of value-added capabilities that enable failover clusters to deliver recovery times below 20 seconds with minimal or no data loss to satisfy virtually all HA/DR needs.

Making It Real

All four options, whether operating separately or in concert, can have roles to play in making the continuum of DR and HA protections more effective and affordable for the full spectrum of enterprise applications. This includes from those that can tolerate some data loss and extended periods of downtime, to those that require real-time recovery to achieve five-9’s of uptime with minimal or no data loss.

To survive the next cloud outage in the real-world, make certain that whatever DR and/or HA provisions you choose are configured with at least two nodes spread across two sites. Also be sure to understand how well the provisions satisfy each application’s recovery time and recovery point objectives. As well as any limitations that might exist, including the need for manual processes required to detect all possible failures, and trigger failovers in ways that ensure both application continuity and data integrity.

About Jonathan Meltzer

Jonathan Meltzer is Director, Product Management, at SIOS Technology. He has over 20 years of experience in product management and marketing for software and SaaS products that help customers manage, transform, and optimize their human capital and IT resources.

Reproduced from RTinsights

Filed Under: News and Events Tagged With: Azure, Cloud, cloud outage, cybersecurity, microsoft azure, multi-cloud, recovery, server failover, SQL, storage

SQL Server Denali And Hadron

January 24, 2018 by Jason Aw Leave a Comment

Microsoft’s latest version of SQL, code named Denali, is currently in CTP. One of the most anticipated feature is something called HADRON. Basically, it is has been described as mirroring 2.0. The best features of HADRON as I can see compared to mirroring as it is in 2005/2008 are as follows:

  • You can query the mirror (now known as a replica)
  • You can have more than one replica
  • Database are grouped into availability groups to ensure related databases always fail over together
  • Support for replicating more than 10 databases

If you want a great preview, check out fellow MVP Brent Ozar’s post, SQL Server Denali Rocks!

From reading Brent’s post I gather Microsoft only plans to include this in the Enterprise version of SQL. That is too bad for the many customers running SQL Server Standard as traditionally there is a significant price jump to go from Standard to Enterprise. However, that is good news for the 3rd party replication vendors out there who are providing similar functionality today on SQL 2005/2008 on Standard and Enterprise Editions.

SteelEye DataKeeper Cluster Edition for SQL Server

While it is not an exact duplicate of HADRON, a multi-site cluster using SteelEye DataKeeper Cluster Edition for SQL Server gives you a great solution for HA/DR without requiring shared storage. So while we wait for Denali and all the application vendors to start supporting Denali you might want to have a look at what SteelEye DataKeeper Cluster Edition can do for you today!

Reproduced with permission from https://clusteringformeremortals.com/2010/12/10/sql-server-denali-and-hadron/

Filed Under: Clustering Simplified, Datakeeper Tagged With: DataKeeper, DataKeeper Cluster Edition, disaster recovery, Hadron, High Availability, SQL

Expert Advice on High Availability SQL Server and Machine Learning Analytics – Blogs, Webinars and Live Events

November 22, 2016 by sios2017 Leave a Comment

SIOS experts in high availability SQL Server cluster protection routinely share their knowledge and provide expert advice through webinars, blogs, and live events.

Blog Post: Step-by-Step Guide to High Availability SQL Server v.Next Linux High Availability
Click here to learn how to deploy a Linux VM in Azure running SQL Server and how to configure a 2-node failover cluster to make it highly available without the need for shared storage. https://clusteringformeremortals.com/category/high-availability/

Blog Post:  Deploying a Highly Available File Server in Azure IAAS (ARM) with SIOS DataKeeper This blog is a step-by-step guide to deploying a two-node File Server Failover Cluster in a single region of Azure using Azure Resource Manager.

Live Webinar: December 15, 2016 –  Webinar: Keeping the Peace with Your Sys Admins while Providing High Availability SQL Server. Join SQL Server MVP Dave Bermingham as he walks through common use cases that cause conflict between SQL DB Admins and VM Admins when SQL Server HA is involved. He will also describe a simple, conflict-free way for SQL Server admins to get what they need for a successful implementation of SQL Server. Register here.

Live Webinar: December 8, 2016 – Understanding vSphere Analytics: Machine Learning vs Threshold-based. Join David Davis, 8-time vExpert and Partner at ActualTechMedia and Experts from SIOS Technology in this real-world, practical, hands-on webinar! Find out the differences between different vSphere analytics approaches and how to choose a solution that’s best for you. Register here.

Recorded Webinar – VMware Guest Based SQL Server High Availability Clusters – Ways to Protect SQL and Maintain Flexibility. Watch this recorded webinar and hear Dave Bermingham, Microsoft Clustering and Datacenter MVP and Tony Tomarchio, Director of Field Engineering at SIOS discuss ways to create a high availability cluster to protect SQL in a VMware environment without sacrificing IT flexibility or important VMware features, and whether you can have a cluster and multi-site replication with VMware. Register here.

Filed Under: Blog posts, News and Events Tagged With: #high availability SQL Server, #ML, #SANLess, Azure, Machine Learning, SQL

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