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Expand Your High Availability Metrics

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Expand Your High Availability Metrics

In the technology field, we love data. We love data about data and all the metrics and measures that our tools can bring. We’ve created industries around analytics, products that capture every detail from thousands of connected devices. We love metrics and measures. In many instances within the higher availability space, we love the high availability metrics that tell us how quickly a system recovered from the failure. We calculate and track the time between detection and remediation, and we obsess over knowing and measuring how much transactional data would be lost in a disaster, system failure, or disk crash.

Ironically, in high availability and disaster recovery (HA/DR) systems, there are some metrics that don’t get enough attention.

Here are eight other high availability metrics you should be watching to manage your environment:

1.  Security alerts

Availability isn’t just about application monitoring and recovery.  Systems that are publicly available are always under attack.  If you aren’t monitoring security alerts and warnings, your applications may be running flawlessly, while your intellectual property is being funneled flawlessly out the door.

2. Idle connections

Idle connections sound harmless, but they are about as harmless as the green leafy kudzu on a southern lawn.  Idle connections take up resources and threaten to fill database pools, congest networks, and stifle performance.  Furthermore, idle connections can indicate a problem in the application layer or database configuration.

3. Long-running queries, commands, or jobs

This applies not just to database queries or jobs, but also to commands and backups.  Long running queries, commands and jobs can be an indicator of poor system health, slow disk speeds, CPU or other resource contention, or deeper systematic, application compatibility or OS problems.

4. Disk IO

Disk IO typically refers to the input/output operations of the system related to disk activity. Measuring disk I/O can help identify bottlenecks, poor hardware configurations, improperly sized disk or poorly tuned disk layouts for a given workload.  Monitoring disk I/O can help tell you if the long running queries are a function of poor sql syntax, poorly coded applications, or latency and access problems.

5. Memory

We all think about how much memory is being used, but memory monitoring goes beyond measuring and looking at free versus used.  Monitoring memory helps you look into bottlenecks, leaks, identify improperly sized systems, understand load, load average, and spikes.  In addition, knowing about memory intensive patterns can help you tune your availability suite to avoid false failures.

6. Disk Space

As VP of Customer Experience I once had the unfortunate experience of waking up early in the morning for an emergency call.  The customer was facing a down production system after a power outage.  When they tried to restart their system their protected applications failed to start.  After a quick check of the error logs it was clear that the root drive was 100% full.  The application could not write to any of the file systems.  Disk space monitoring is available in many forms and ways and having it as a metric can prevent unnecessary problems and costly last-minute scrambles to add more. .

7. Errors and alerts

Errors, alerts, and recovery messages in the logs are another good metric to consider.  Your availability solution may be keeping your clients online and happy, but it may also be masking an issue that will need your attention soon.  Adding log monitoring for FATAL, PANIC, and key ERROR messages can help you identify issues that your availability solution is frequently recovering from, such as database crashes, application panics or core dumps, or fatal errors requiring a cold restart.

8. Recovery numbers

Similar to monitoring errors and alerts, the recovery numbers can tell you a lot about the health of your system’s availability.  If you are averaging more than one application recovery per week, you’re likely experiencing something more than your normal availability protection.  And while the recovery was successful in restarting your application or system, too many of these false or even real recoveries isn’t healthy.

The list of HA/DR metrics that we can monitor and the tools to monitor them are growing by leaps and bounds.  Be sure that you and your team consider expanding your current data capture and analysis to include those that make for the best higher availability system possible.

— Cassius Rhue, VP, Customer Experience

Reproduced with permission from SIOS

How to Deliver High Availability for SQL Server in Linux Environments

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How to Deliver High Availability for SQL Server in Linux Environments

How to Deliver High Availability For SQL Server in Linux Environments

If your organization is running business-critical Microsoft SQL Server on Linux, your IT team undoubtedly knows how challenging continually maintaining high availability, performance and security can be. Particularly difficult is how to ensure high availability with robust replication and automatic failover. Using open-source software and an easily configured HA SANless cluster solution can offer a simpler maintenance approach without sacrificing the safety and performance your organization requires.

Limited High Availability Options for Linux

Most Linux distributions give IT departments two inferior choices for high availability: either pay more for the SQL Server Enterprise Edition to implement Always On Availability Groups, or struggle to make complex do-it-yourself HA Linux configurations work well—something that can be extraordinarily difficult to do.

The problem with using the Enterprise Edition is that it undermines the cost-saving strategy for using an open-source operating system on commodity hardware. For a limited number of small SQL Server applications, it might be possible to justify the additional cost. But it’s too expensive for many database applications and will do nothing to provide general-purpose HA for Linux.

Providing HA across all applications running in a Linux environment is possible using open-source software, such as Pacemaker and Corosync, or SUSE Linux Enterprise High Availability Extension. But getting the full software stack to work as desired requires creating (and testing) custom scripts for each application, and these scripts often need to be retested and updated after even minor changes are made to any of the software or hardware being used. Availability-related capabilities that are unsupported in both SQL Server Standard Edition and Linux can make this effort more challenging.

Finding an Alternative High Availability Solution for SQL Server in Linux

To make HA both cost-effective and easy to implement, you may want to consider two different, general-purpose approaches.

One is using storage-based systems that protect data by replicating it within a redundant and resilient storage area networks (SANs). This approach is agnostic with respect to the host operating system, but it requires that the entire SAN infrastructure be acquired from a single vendor and relies on separate failover provisions to deliver high availability.

The other approach is host-based and involves creating a storage-agnostic SANless cluster across Linux server instances. As an HA overlay, these clusters are capable of operating across both the LAN and WAN in private, public and hybrid clouds. The overlay is also application-agnostic, enabling organizations to have a single, universal HA solution across all applications. While this approach does consume host resources, these are relatively inexpensive and easy to scale in a Linux environment.

Most HA SANless cluster options provide a combination of real-time block-level data replication, continuous application monitoring, and configurable failover/failback recovery policies to protect all business-critical applications, including those using Always On Failover Cluster Instances available in the Standard Edition of SQL Server.

SIOS Technology Corp. offers more robust HA SANless cluster solutions for Linux with advanced capabilities that are designed to free IT from the complexity and daily challenges of supporting and optimizing computing infrastructures. The SIOS Protection Suite solution with LifeKeeper provides:

  • Continuous monitoring of the entire Linux application stack
  • Complete Application-Aware Protection with its application recovery kits (ARK) for fast, safe recovery or failover of complex applications and databases
  • Wizard-driven setup for Linux clustering
  • Configuration flexibility, such as using a traditional shared-storage cluster or software to synchronize local storage in a SANless cluster configuration

For example, a SANless cluster can handle two concurrent failures. The basic operation is the same in the LAN and WAN, as well as across private, public, and hybrid clouds.

In a typical two-node cluster server #1 is initially the primary that replicates data to servers #. It experiences a problem, automatically triggering a failover to server #2, which now becomes the primary.

In this situation, the IT department would likely begin diagnosing and repairing whatever problem caused server #1 to fail. Once fixed, it could take over as the primary or server #2 could continue in that capacity replicating data to servers #1.

With most HA SANless clustering configurations, failovers are automatic, and both failovers and failbacks can be controlled by a browser-based console.

For further information about SIOS LifeKeeper and Protection Suite solutions, visit SIOS SAN and SANless High Availability Clusters for Cluster Server Environments.

Reproduced with permission from SIOS

Lessons in Cloud High Availability from the Movies

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Lessons in Cloud High Availability from the Movies

Lessons in Cloud High Availability from the Movies

Joseph Lalonde of jmlalonde.com  has a blog highlighting the leadership lessons from popular movies such as Hancock, The Greatest Showman, and Frozen II.  In credit to Joseph’s inspiring leadership lessons, here are four high availability lessons on cloud migration from Disney’s Frozen II.

Disney’s Frozen II and Cloud Migration Lessons

In Disney’s animated adventure Frozen II the characters Anna, Elsa, Kristoff, Olaf and Sven leave Arendelle to travel to an ancient, autumn-bound forest of an enchanted land. In the adventure, they set out to find the origin of Elsa’s powers in order to save their kingdom.  Aside from being fun for a father of six girls, the movie is also ripe with leadership, life, and high availability lessons.

1.    You can’t go into cloud migration without the proper help.

When Elsa, Anna, Kristoff, Olaf and Sven arrive at the place where the mysterious voice has been calling them, they stand outside an enormous cloud.  When Olaf and Kristoff attempt to enter, they are bounced back and repelled.  It is only when Elsa approaches the cloud with her magic that the portal opens and they enter.

When migrating to the cloud, there will be a lot of voices calling you.  Some will beckon you to AWS, or Azure or GCP, or a myriad of others.  But, no matter which you intend to go with, know that you will need the proper help for a successful entry.  This help should include:

  • Architects knowledgeable of the platform, especially the networking aspects
  • Application administrators who understand the applications installation, configuration, operation and maintenance characteristics
  • Security and OS administrators
  • A cloud partner representative
  • A knowledgeable availability expert for deploying critical applications in highly available architecture

2.    Things will not make sense when you are older, so document and iterate.

While walking through the enchanted forest, Olaf begins experiencing the strange phenomenon and magic of the forest.  As he does, he begins to sing:

  • This will all make sense when I am older
    Someday I will see that this makes sense
  • One day, when I’m old and wise
  • I’ll think back and realize
  • That these were all completely normal events
  • I’ll have all the answers when I’m older

The song concludes with the rousing finish of:

  • ‘Cause when you’re older
  • Absolutely everything makes sense
  • This is fine

Stop.  If things don’t make sense to you when you are starting out in your cloud journey, take the time to make them make sense.  If you are using an agile mindset, launch an investigation spike on the singular topic or topics of confusion.  For example, if you don’t understand the magic of the VPC, Security Group, Availability Zone or Set, Region, or Region to Region concepts today, they will make even less sense later down the road when you return to this configuration months later.  If the test results don’t make sense, don’t move on, run them again.  Also, remember to document the architecture, not just the details you think are important, but the details that the older you who have moved through six other projects and is facing a deadline would want to know to make it all make sense.

3.    Don’t go running into the fire. Choose the right cloud high availability solution.

After a brush with the wind spirit, the enchanted forest is set ablaze by the fire spirit.  As the fire spirit spreads chaos, and fire, Elsa charges off with icy blasts to cool the fire and calm this spirit.  In her zeal, Anna runs into the fire behind her sister and has to be saved.  When at last the two are reunited, Elsa admonishes her sister- “You can’t just follow me into fire”.  The feisty Anna replies, “You don’t want me following you into fire?  Then don’t run into fire!”

Migrating to the cloud and choosing the right availability solution for you can be stressful enough without complicating it by making unrealistic schedules with untested theories and scenarios.  No leader of a deployment team wants his or her team in a fire drill, so don’t knowingly run into one.  Create a plan.  Establish checkpoints and milestones.  Include realistic risk and risk management strategies.  Communicate frequently with vendors and partners, and especially with your team.  Test well, and understand backup and backout plans.

4.    Don’t get stuck in the past re: what you bring in your cloud migration.

There is a song woven throughout the movie, “All is Found”  with the chilling chorus – “Dive down deep into her sound / But not too far or you’ll be drowned.”  Elsa dives down into the deep as the movie peaks and her search and exploration of the past leave her Frozen, her last gasp a burst of flurries to warn and inform her sister.

As one of the heads of our Customer Experience Team at SIOS Technology Corp., I have witnessed too many deployments and migrations get stuck in a comparison trap.  The phrase goes like this, “In our old data center, we” or “The old system could do that.”  It may be true that your old system of fixed systems, dedicated resources, large teams, specific networking, and high cost, high feature SAN storage could do that.  (Although, truthfully, sometimes I’ve seen the curtain peeled back and on-premise didn’t really do that either).  As you migrate to the cloud, understand what makes sense to mimic in the cloud and what doesn’t.  Understand why the system was architected that way on-premises and using the help, “lesson 1, and the learning of lesson 2, make decisions that make sense.

Which leads me to the final lesson.

5.     There will always be two kingdoms: on-premises and in the cloud.

At the end of the movie, Anna becomes queen of Arendelle once ruled by her sister Elsa, while Elsa stays and leads the people of the Northuldra.  There is one who stays in or near the forest once surrounded by mystery and cloud, while the other returns to the familiar land.

As you consider migration to the cloud and your High Availability strategy, remember there will always be two kingdoms.  Your migration strategy would do well to remember that you will always have a need for an on-premise data center to partner with your cloud deployments.  Perhaps it isn’t as sprawling as it once was, but not every workload or critical infrastructure can be repurposed and packaged for the cloud.  Having an HA solution and strategy that can equip and enable both “kingdoms” is essential.

Going to the cloud takes the right team, the right tools and the right solutions, and a strategy and plan to get there, without going through fire.  As you migrate to the cloud, be willing to confront the past, understand it, and remember not to get stuck there.  And, like the two sisters of Disney’s Frozen II, you’ll do well to remember every beautiful enterprise story has two sides, on-premise and cloud just might be yours.

— Cassius Rhue, VP, Customer Experience

Reproduced with permission from SIOS

 

Planning is Key to Enterprise Availability (and to a Happy Marriage)

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Planning is Key to Enterprise Availability (and to a Happy Marriage)

Planning is Key to Enterprise Availability (and to a Happy Marriage)

Planning dates and getaways, fabulously romantic dinners are a great part of loving your spouse well.  Seminars and workshops overflowing with tips for improving your relationship abound in nearly every area of the world.

But, listen in on the training session provided by SIOS Technology Corp. Project Manager for Professional Services, Edmond Melkomian, and you’ll quickly learn that planning dinners and anniversary retreats aren’t the only way to love your spouse well.

In a recent class on SIOS Protection Suite for Linux, Edmond shared three tips that help you love your spouse well in an enterprise world: plan, plan, plan.

1.   “Plan to plan” your enterprise availability solution

1. “Plan to plan” your enterprise availability solution

In his course, Edmond Melkomian asked students to name the first thing you should do when deploying an enterprise solution.  His answer, “Plan, plan, plan.”  It seems obvious, but the first step is to start making the plan.  A fairly decent start for a plan includes developing the details for each of the project phases, such as milestones, checkpoints, risks, risk mitigation and strategies, stakeholders, timelines, stakeholder communication plans.  A decent plan will also include details about kickoff, sign-off and closure, and resources (staffing, management, legal/contracts).

Plan to create, review, modify, and update your plan throughout the solution lifecycle.

2.   Plan what to deploy for enterprise availability

Plan what to deploy.  It is likely that a large portion of your enterprise infrastructure exists beyond the realm of the current team’s lifespan with your company.  As you migrate to the cloud, or update your availability strategy, it is worth the time and effort to make a plan regarding what to deploy.  Focus your plan on ensuring that you deploy redundancy at all critical components, network, compute, storage, power, cooling, and applications.  All data centers and cloud providers typically ensure cooling, power, and network redundancy to start.

A number of firms offer architectural teams, cloud solution providers, availability experts, application architects, and migration specialists who help teams discover critical and sometimes hidden dependencies as well as high risk areas vulnerable to Single Points of Failure (SPOF’s).  This investigative work will feed into your plan of what to deploy and/or update in your availability strategy.

Plan on reviewing what you need to deploy.

3.   Plan to keep a QA/pre-production cluster for reliable availability

When I was in the SIOS Technology Corp. development team, I’ll never forget a Friday night call with a long time, but frantic customer.  Earlier in the month a frequent customer unsuccessfully deployed a new software solution into a production environment.  The result was a massive failure.  He called our 800 number at 4:30pm (EST) on Friday.  Why do I recall that exact time?  Friday was date night.  My wife and I had dinner plans, a babysitter for the six girls on standby (by the hour), and hopes for a romantic and relaxing evening.  I was just about to head out for the day when the phone rang.  After a tense first hour, we were back up and running.  This unfortunate episode could have been avoided or mitigated by keeping a UAT or QA system on hand.

As Harrison Howell, the Software Engineer for Customer Experience at SIOS Technology Corp. noted in his blog 6-common-cloud-migration-challenges the limits of on-prem are no longer the same limits.

Customers coming from an on-prem system need to remember that resources are no longer a limiting factor. In the cloud, systems can be effortlessly copied and run in isolation of production, something not trivial on-premises. On-demand access to IT resources allows UAT of HA and DR to expand beyond “shut down the primary node”. Networks can be sabotaged, kernels can be panicked, even databases can be corrupted and none of this will impact production! Identifying and testing these scenarios improves HA and DR posture.

Plan on deploying and keeping a UAT system for HA and DR testing.  As Harrison mentions, “identifying and testing [issues]” “improves [your overall] HA and DR posture,” and that improves your chances of a successful date night.

4.   Plan regular maintenance and updates (including documentation)

Lastly, plan times for regular maintenance and updates to maintain Enterprise Availability.  Your enterprise needs to remain highly available to remain highly profitable and successful.  Environments don’t remain stagnant, and patches, security updates, expansion, and general maintenance are a regular occurrence from inception to retirement.  Creating a plan for how and when you will incorporate updates and maintenance into your enterprise will ensure that you are not only kept up to date, but that you minimize risks and downtime while doing it.  Be sure to include in your plan the use of a test system.  Develop a planned routine and process for validating patches, kernel and OS updates, and security software, and don’t forget to update the project documentation and future plans as you go and grow.

If you can remember to plan for a highly redundant, highly reliable and highly available system upfront, plan to keep a QA/Pre-production cluster after Go-Live, and plan for regular maintenance and updates you will also be able to keep your plans with your spouse for date night.  And not just date night, but you’ll also be able to keep your night’s free from 3am wake up calls due to down production systems.  This is my tip for loving your spouse well.

I love my wife and so I help customers deploy SIOS Technology Corp.’s DataKeeper Cluster Edition and SIOS Protection Suite for Windows and Linux products as a part of a highly available enterprise protection solution.  Contact SIOS.

— Cassius Rhue, VP, Customer Experience

Article reproduced with permission from SIOS

 

High Availability Software is Insurance Against SAP Downtime

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We all need to buy insurance – for our cars, our houses, our lives. Nobody likes to pay money for a service that we hope we never have to use. But we all know that we should have it just in case. Most people either put off insurance until something awful happens, buy the cheapest, or actually do their homework and buy it from someone they trust.  This last group usually fares the best.

High Availability Software is Insurance Against Downtime

Insurance is often for consumers, but it’s critical to businesses too. You have computer systems and applications that run your business.  If they fail for some reason, you want your business to continue to run or it could cost millions of dollars in lost business through lost transactions and customer data, and irreparable damage to your reputation with your customers. High availability software is your “insurance” against system downtime. This is not something you can ignore. This is not something you can trust that will come along with your hardware or software infrastructure. You want to use high availability solutions from a company that has decades of expertise in high availability and knows how to keep your systems up and running.

A trusted high availability software company should: 

  • Provide a single solution that is platform agnostic – usable on-prem, in the cloud, and on all of your hardware and software platforms
  • Have a product that is easy to configure and set up without having considerable application expertise
  • Know your applications and when your applications are having a problem
  • Take the proper action to attempt to restart or failover applications
  • Fail over the application to a secondary server, maintaining application best practices, and bringing the application back up in the proper order

One of the key applications used in enterprises today is SAP S/4HANA, based on the HANA in-memory database.  Most SAP customers will be required to run the HANA database with SAP by 2025.  You want to find an intelligent HANA availability solution from a company that knows high availability, that knows SAP, knows HANA, and knows what to do to ensure that your critical SAP applications, and your business, continue to run smoothly.

SIOS Technology is the company you can trust for a reliable High Availability Software. The 9.5 release of the LifeKeeper for Linux product contains a new HANA Application Recovery Kit. This will provide you with all you need to keep your SAP and HANA environment running.  Want more information about this release? Watch this interview.

Reproduced with permission from SIOS