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Think Before You Script: Best Practices for Gen/App Recovery

September 20, 2025 by Jason Aw Leave a Comment

Think Before You Script Best Practices for GenApp Recovery

Think Before You Script: Best Practices for Gen/App Recovery

SIOS Recovery Kits provide a wealth of best practices for application-aware monitoring and recovery.  In general, each SIOS recovery kit provides a step-by-step programmatic approach to restoring the application, database, or service in accordance with High Availability (HA) best practices.  The SIOS Recovery Kits provide the intelligence needed to restore operation after a normal system shutdown, after an unexpected system failure or crash, and even in the case where the application, database, or service itself crashes or becomes unavailable.   In addition, each recovery includes experiential wisdom and improvements from over two decades in the field.

However, if a customer still needs to roll their own script for providing HA, SIOS LifeKeeper for Windows and SIOS LifeKeeper for Linux include an option for script integration via the Generic Application (Gen/App) Recovery Kit.

Best Practices for Writing Gen/App Recovery Scripts

1. Use Modern, Supported Scripting Languages for Gen/App Recovery

A common practice with existing solutions is to use the old existing scripts on new systems and architecture.  However, it is essential to make sure you are using a modern, supported scripting language.

2. Avoid Hardcoded Values in Gen/App Scripts

Using hardcoded values can cause portability issues, as well as challenges with long-term maintenance.  Avoid using hard-coded values that are subject to change in future deployments, for example, directory paths, user names, or similar.

3. Practice Code Reuse to Improve Gen/App Script Quality

Duplicate code is a common problem in customer-developed scripts.  Duplicate code creates quality, maintenance, and troubleshooting problems.  Practice code reuse, such as inheritance, functions, and subroutines.

4. Choose Meaningful Names for Functions and Variables

Descriptive variables are more helpful than single-character variables such as ‘n’ or ‘i.  When looking at code months or years later, will the variable ‘n’ mean as much as iReturnCode?

5. Remove Unused Functions and Variables to Prevent Code Bloat

While meaningful names for functions and variables are important, avoid cluttering the code with unused variables and functions.  Declaring variables and not using them can create confusion during future updates and troubleshooting.  While the days of 8 MB of memory are long gone, additional variables or functions that provided limited reuse or no additional value are still burdensome and create code bloat.

6. Verify All Input Parameters for Reliable Gen/App Execution

In the rush to get something working, don’t ignore input variable validation.  Verify all input to the script and to functions.  Don’t assume that if “we got here,” all of our inputs are valid.

7. Log Helpful and Actionable Messages

Consider what output needs to be logged for status/progress, error conditions, or troubleshooting.  Each message should be thoughtfully considered and appropriately worded to provide helpful feedback to operators and future developers.

8. Check Return Codes on All Method/Function/API Calls and Take Defensive Action

Commands that are executed within the body of the script or function will have return codes, explicitly pass, fail, or other.  Be sure to check, log, and properly handle both expected and unexpected return codes from methods, functions, and API calls.

9. Use Defensive Programming Techniques

Apply best practices for defensive programming, including least privilege access, input validation, error handling, etc.

10. Test Gen/App Recovery Scripts Beyond the Happy Path

Working code is not enough.  Develop a robust validation plan and test the code extensively, especially beyond the happy path when everything is expected to work.

11. Use Version Control for Script Management and Troubleshooting

Use version control and code management tools.  Version control is essential for troubleshooting, management, and tracking the inevitable fixes required for your scripts.

12. Catch Errors Early with Code Inspections and Peer Reviews

Use code inspections and peer reviews to increase the resilience and robustness of the code.  Code reviews help find problems early and reduce the cost, risk, and burden of late-stage failures and bugs.

13. Verify Permissions Required for Execution in Gen/App Recovery

Having well-organized, modern, reviewed, inspected, tested, and controlled code is an essential part of a well-crafted gen/app script.  However, the best-coded script will fail to execute if it does not have the right permissions.  Ensure that the script has the correct permissions to execute standalone as well as under the service/user accounts of the HA solution.

14. Comment Code Clearly to Explain Logic and Business Use Cases

Provide comments that help explain the business logic and use case, describe expected function inputs and returns, and contribute to overall understanding.  Well-written code still needs comments, especially if it is not obvious what business logic or requirement is being addressed.  An example comment block could look like:
Name:

Purpose:

Preconditions:

Postconditions:

Returns:

Ready to Simplify Gen/App Recovery with Confidence?

Don’t leave high availability to chance. With SIOS LifeKeeper and the Generic Application (Gen/App) Recovery Kit, you can safeguard critical applications, streamline recovery, and reduce downtime.

Request a demo today to see how SIOS can help you achieve reliable, cost-effective high availability and disaster recovery.

Author: Cassius Rhue, VP, Customer Experience at SIOS

Reproduced with permission from SIOS

Filed Under: Clustering Simplified Tagged With: Application availability, High Availability

High Availability Health-Check Services, Optimization, and Training

August 27, 2025 by Jason Aw Leave a Comment

High Availability Health-Check Services, Optimization, and Training

High Availability Health-Check Services, Optimization, and Training

Customers regularly engage SIOS for consultancy services such as high availability (HA) health check services and training. This helps customers keep their IT infrastructure in good working order and keeps their staff trained to operate it.

High Availability Health-Check Services

Health check services are a Professional Services offering from SIOS that checks the customer’s SIOS server infrastructure and produces a report for the customer. A detailed review of the SIOS HA LifeKeeper environment is performed, as well as a thorough examination of the product logs and customer run logs. During this review, version levels, communication paths, quorum, Application Recovery Kits, and tuning parameters are examined and compared against recommended settings. A report is generated with any potential risks outlined and actionable suggestions for improvements.

High Availability Optimization

Optimization of High Availability services can be broken down into two areas:

  • High availability optimization – this optimization reduces downtime and maintains the operational uptime of a system. This is achieved by the use of system-initiated failovers and user-initiated switchovers to a backup hardware system that can take over when a primary system fails or is manually switched over. A Disaster Recovery (DR) node may be positioned on a WAN so that if the main LAN-based nodes go down, fast recovery can be achieved by failing over to the DR node. Backups may also be routinely made, so that recovery of specific files can be performed if needed.
  • Cost-optimized high availability – this optimization examines a customer’s system to determine the best way to offer redundancy, while keeping costs down. This may involve using cloud services for scaling and utilizing lower-tiered services to reduce cost. Serverless architectures with a pay-per-use model can also be used. All of this reduces hardware costs.

High Availability Training

SIOS offers on-demand high availability product training for LifeKeeper for Linux and DataKeeper for Windows products through the Udemy training platform.

Additionally, SIOS offers remote custom training for organizations via the Professional Services organization for these products, which come with training materials and self-guided exercises. For the DataKeeper course, an Individualized breakout/consultancy session is available.

SIOS Technology Corporation provides high availability cluster software that protects & optimizes IT infrastructures with cluster management for your most important applications. Request a demo today and see how easy clustering can be.

Author: Paul Scrutton, Software System Engineer at SIOS Technology Corp.

Reproduced with permission from SIOS

Filed Under: Clustering Simplified Tagged With: High Availability

Eliminate Shadow IT High Availability Problems

August 20, 2025 by Jason Aw Leave a Comment

Eliminate Shadow IT High Availability Problems

Eliminate Shadow IT High Availability Problems

Many of us are familiar with the term Shadow IT.  Most often, the term is used to refer to technology systems, software, subscriptions, and other services that are used by employees of a particular company without the overall approval, knowledge, or oversight by the company’s official IT department.  Most often, these systems, services, or subscriptions are downloaded and installed, or used and managed by individuals outside of the IT department.

For example, perhaps your company officially uses Windows 365, but others prefer Dropbox, so they configured a Dropbox account to share files instead of OneDrive.  Another example of Shadow IT occurs when a company has settled on one messaging platform, but other teams or departments within the company download and configure Zoom for Slack or WhatsApp.

Common Examples of Shadow IT in the Workplace

Shadow IT occurs in many different areas, from messaging to meetings, coding tools to storage.  While most teams and organizations that have some form of Shadow IT do not deploy them maliciously or with evil intent, the presence of Shadow IT nevertheless introduces risks.

These services, software, systems, and subscriptions introduce potential risks, including:

  • Security issues
  • Data compliance
  • Support challenges
  • Management and maintenance issues (due to sprawl)
  • Additional cost (licensing and manpower)

How Shadow IT Impacts High Availability (HA)

In addition to security and data compliance risks, Shadow IT may also be introducing a significant High Availability (HA) risk.

While many examples of Shadow IT mentioned online are related to messaging applications, meeting tools, IDEs, and development applications, the breadth of Shadow IT can also impact High Availability (HA).  When Shadow IT includes the deployment of systems that store critical information and data, this creates a High Availability risk.

These systems, because of the nature of the data stored on them, need to be monitored and protected by a commercial HA solution.  In addition, critical data that is essential to business functions needs to be highly available and protected against data loss by a replication solution, backup solution, or both.

Business Risks of Unprotected Shadow IT Critical Applications

Lack of High Availability Protection

Often, when a team has deployed a system without input or authorization from IT, it may not be monitored, protected, backed up, or even paired with a HA system for failover recovery.  This is a significant risk to the organization’s HA strategy.  If the data is critical for an internal organization or project, leaving it unprotected could jeopardize the business.

Financial Losses and Business Disruption from Shadow IT Downtime

Shadow IT risks also arise when essential applications are downloaded, installed, and configured without the official IT department’s oversight.  If essential applications are running on an unprotected system or without HA monitoring and recovery protection, the risks and results can be catastrophic.  Imagine the scenario where an application is essential to the Sales workflow and orders system.  Because the software is a part of Shadow IT Infrastructure, the IT team has no knowledge of its use or its impact on the business.  If the application fails, the business will be impacted. Depending on the type of failure, the impact on operations could cost hundreds of thousands to millions of dollars.

When the critical application fails, without proper HA protection, the manual recovery process can be cumbersome, complex, and prone to errors.  This risk to the operation is due in part to the growing complexity of application environments and technical requirements. Exacerbating the complexity, when an application falls into the category of Shadow IT, the limited knowledge of the application’s existence and recovery procedures can lead to unplanned and unprepared actions to restore full operation.

Steps to Identify and Eliminate Shadow IT HA Problems

Identify All Shadow IT Systems That Impact High Availability

The first step in avoiding HA disasters due to Shadow IT is to identify the subscriptions, services, systems, applications, data, and software that have become a part of the unmanaged IT infrastructure.  Gain visibility into what tools are being used, by whom, and for what purpose.
This can be done by utilizing existing network monitoring, cloud monitoring, or endpoint detection tools.  You can also engage with the IT security and infrastructure analysis service vendors to perform a helpful audit of tools, services, systems, and subscriptions.

Remediate Risks and Remove Unnecessary Shadow IT Assets

Once this identification has been done, the next step is to start with remediation.  Remediation includes eliminating unused and unnecessary systems as well as implementing controls and processes for the administration of each acquired item. Be sure to adjust workflows for eliminated systems, as the removal of systems can impact several teams and activities within the organization.

Protect Critical Applications with High Availability and Replication

For systems, applications, and services that must remain, especially those housing critical data and applications, deploy a commercially available HA and replication solution to protect the business from the key threats of application downtime, data loss, system unavailability, and downtime of the systems hosting the critical data, applications, or tools.

Educate Teams on the Risks of Shadow IT to HA Systems

Lastly, educate the organization about the dangers and risks associated with Shadow IT, including the risks due to dependencies, architecture complexities, data vulnerability, and unexpected downtime of unprotected systems.

Build a Resilient HA Architecture to Eliminate Shadow IT Downtime

Shadow IT is not limited to meeting and messaging tools, development systems and services, nor apps like Dropbox, OneDrive, Box, and online services.  Shadow IT tools often lack proper backup and recovery mechanisms, as well as uptime guarantees.  As a result, critical business processes and data could be inaccessible or even permanently lost due to a failure scenario.  When not officially integrated into HA protection, failures at the system, application, network, or storage layer can lead to broken workflows, inefficiencies in processing, or business downtime and reputational loss.

Eliminate Shadow IT HA problems by creating a well-architected HA environment for the systems, services, applications, and workloads that your company identifies and chooses to incorporate into the official IT department offerings.  This architecture should include a commercially available HA, data replication, and backup solution that is deployed on an enterprise-ready hypervisor.

Ready to strengthen your HA architecture with proven expertise? Request a demo today and see how SIOS can help you design and deploy a high availability solution that protects your business from Shadow IT downtime.

Author:Cassius Rhue, VP, Customer Experience

Reproduced with permission from SIOS

Filed Under: Clustering Simplified Tagged With: High Availability

Achieving High Availability Cost-Effectively

August 15, 2025 by Jason Aw Leave a Comment

Achieving High Availability Cost-Effectively

Achieving High Availability Cost-Effectively

These days, applications and data are the lifeblood of most organizations, and everyone expects that the applications and data they need to get their work done will be available. But ensuring true application and data high availability (HA) – by which we mean the assurance that you can interact with them at least 99.99% of the time – can sound like a costly proposition. But a clear understanding of where to apply HA and how to do so cost effectively can more than justify the cost. In fact, it can protect you from the extensive costs and consequences of downtime and disaster. The question is, how can you determine how best to invest in an HA infrastructure?

This Networking Computing article by a SIOS solutions architect looks at the considerations for determining which applications and data justify the investment in an HA infrastructure and suggests cost-effective steps that organizations can take to improve the availability of those systems and data stores that it will opt not to protect with a full HA infrastructure.

Want to take the next step with SIOS? Request a demo today to see how SIOS can help you protect critical workloads, minimize downtime, and ensure seamless high availability.

Author: Beth Winkowski, Public Relations

Reproduced with permission from SIOS

Filed Under: Clustering Simplified Tagged With: High Availability

Why Company History Matters in HA

August 5, 2025 by Jason Aw Leave a Comment

Why Company History Matters in HA

Why Company History Matters in HA

There are many places to start with regarding building the plan, strategy, design, and architecture for a highly available cluster.  Of course, wise builders want to understand the basic requirements: two nodes or three, RTO under 10 minutes or under five minutes, RPO of near zero or absolutely zero.  Architects also want to understand how many nodes, and how the hardware and network can be made resilient.  Will you deploy in the datacenter, on the cloud, or a mixture of both?  In addition to understanding the architecture of the underlying hardware, requirements gathering and design also lead to gaining an understanding of the critical applications, the High Availability (HA) software, processes, and governance procedures that will need to be followed, additional dashboards and integrations required for reporting, monitoring, and alert distribution.  All team members will also want to understand the basics of recovery and failover orchestration, of course.

Why Company and Solution Provider History Matters in High Availability

But one thing that often gets overlooked in the deployment of High Availability is company history.  Of course, if you are going to entrust your enterprise environment to a monitoring, alerting, recovery, and failover orchestration solution, you’d want to know and understand who they are, what they do, and how long they’ve been doing it well. Is this a new startup company located in Buford, Wyoming, a company available in the US only, or a global company that happens to have an HA offering in mothballs that are only trotted out to close other parts of a deal?

As you build your architecture, of course, you need to know that the HA company knows, understands, and does HA well.  But, and this is a big one, the most important history your team needs to know when architecting your HA solution isn’t theirs but yours.

As VP of Customer Experience, I’ve worked with numerous customers, teams, architects, and solution integration teams on deploying HA solutions across on-premise and off.  In many of these discussions, one overlooked factor in deploying a sound infrastructure and HA architecture is the history of the company itself.  So, why does your company, or the company you are architecting HA for, matter?  Five (5) ways in which company history should impact your HA architecture

Five Ways Company History Shapes HA Architecture

Here are Five (5) ways in which company history should impact your HA architecture:

1. Company Size (Too big or too small)

What is your company’s history with regards to the HA team?  Does your company have too many people on the team, with conflicting or overlapping roles and responsibilities?  Or does your company have a team that is undersized, even as it overachieves?  Depending on the history of your company and its size over that time, you may need to make adjustments in your design for additional authentication, more granular permissions and restrictions, etc.  If your team is small, perhaps adding the burden of developing and maintaining a free solution would be too much of a burden.  If your team is large, with many roles and overlaps, and time to develop custom solutions, consider if a commercial solution would be a better fit to free those resources up for new development, additional improvements, or even greater efficiency in the day-to-day operations.

2. Company Life Cycle (Every five years or not until it breaks)

What is your company’s life cycle history?  Does your CIO/CTO revamp your entire infrastructure on a fixed cycle, or are they more of an “If it ain’t broke, don’t fix it,” type?  If your company has a long history of trading out and replacing solutions and providers, then your architecture will need to be more robust to handle the swapping in and out of components and pieces. In this case, your HA architecture will also need to factor in offboarding, end of life, and onboarding of a potentially new solution within a short period of time.  A key for this type of high turnover will be to limit custom work and hard dependencies.

On the other hand, if your HA solution will be in place for ten years or more, you’ll want to make sure that your vendors provide maintenance and extended support for the critical components within your infrastructure.  Your architecture will also need to heavily weigh the challenges that might be encountered with various software solutions and interoperability as the solution ages past the standard support lifecycle, and how to mitigate those risks.

3. Company Staffing (The revolving door or the lone ranger)

As VP of Customer Experience, one of my most shocking memories was working with a company to architect a solution for HA.  Within one week of the go-live date, the project manager for that team announced that he and his whole team had been terminated.  The go-live would be transferred to a new team, both new to the company and new to HA.  As I would later learn, company Z had a revolving door policy with IT and the administrators for their HA environment.  Most, if not all, of their resources were contractors.  If your company has a history of high turnover, then your architecture and design must include a runbook, and the process and procedures for maintenance need to also include training; formal product training, procedural testing, administration training, and chaos scenarios.

The revolving door isn’t the only company staffing history to be aware of.  The Lone Ranger is another scenario that is critical to know and understand.  At SIOS, our team joined a bewildered project manager looking for any answers and information regarding their enterprise systems, both involving SIOS and beyond.  The Lone Ranger had left the company due to unspecified reasons, and upon their departure, new members of the team discovered that a lot of tacit knowledge was undocumented and unaccounted for in any documents they could find.  When designing and building your architecture, knowing the type of staffing and history of staffing can help you design solutions properly, and may lead your team to choose a solution that is commercially available and staffed with services for the unfortunate Lone Ranger departures.

4. Company Past Disasters

Company disasters and downtime are another historical point that needs to be understood well by designers of HA solutions.  Typically, company disasters make their way into future architecture designs as requirements.  The past disasters, including their root cause, risk mitigation strategies, detection, prevention, and reporting recommendations, are often added to the deck of initial requirements.  However, digging into the history of the disasters may uncover more requirements and factors that need to be accounted for.  As VP of Customer Experience, our team learned a tremendous amount of data for building a better experience for several of our clients by understanding the company’s disasters.  In one instance, unattended VM maintenance was a big part of the company’s strategy, but also a source of many company availability issues.  While working with architects, our services team not only addressed application availability but helped the design team account for backup and recovery, maintenance and upgrades, and rollback strategies that maintain availability in the event of an automated failure.

5. Company Culture

As VP of Customer Experience, our team works closely with customers and partners who are passionate about application availability, adhering to the most stringent of Service Level Agreements (SLA) and Service Level Objectives.  As we worked with these teams, their designs and architecture specifications reflected a company culture that considered availability (architecture, design, hardware, networking, applications, cluster software, people, and process) as an indispensable part of their business.  Sadly, not all companies have this type of company culture.  Knowing the history of your company’s culture will definitely shape the way you implement HA, bringing out the best in design and architecture, either for adherence to the culture or as a method to improve culture and business success.

Don’t Overlook the Role of Company History in HA Decisions

Yes, the company history of the datacenter or cloud provider is important.  Knowing the history of Lou’s Low Cost Cloud, LLC (no offense to Lou), which has been hemorrhaging equipment, while running from the mostly un-air-conditioned garage of Lou’s parents’ home, is important if you were considering Lou for your datacenter.  Yes, the company history of the application and the HA vendor is also important.  Knowing the history of your ERP, Database, and frontend application provider is key to assessing and mitigating risks, understanding deployment patterns and methodology, and gaining confidence that timely fixes, updates, security, and support will be a cornerstone of your architecture.  But, do not underestimate the importance of knowing your own company history and how the critical failures should shape your new and ongoing HA decisions and infrastructure.

Ready to strengthen your HA architecture with proven expertise? Request a demo today and see how SIOS can help you design and deploy a high availability solution built for your company’s unique history and future needs.

Author: Cassius Rhue, VP, Customer Experience

Reproduced with permission from SIOS

Filed Under: Clustering Simplified Tagged With: High Availability

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