SPOF: What Is a Single Point of Failure?

Here’s what a single point of failure (SPOF) is:

A single point of failure stops the entire system from working.

SPOF in IT is when a single component of a system causes the entire system to fail.

It can expose your personal data and what’s worst is can be costly to repair.

If you want to learn all about what a single point of failure is and how to recognize one, then this article is for you.

Let’s get started!

SPOF: What Is a Single Point of Failure? (All the Info)

What Happens to Your PC During Single Point of Failure?

A single point of failure (SPOF) in IT causes an entire system to crash.

It can expose private data and, in many cases, is costly to repair.

If you’ve stumbled upon this article because you’re experiencing an IT-related SPOF, know you’re not alone.

In 2015 Amazon’s DynamoDB database malfunctioned for multiple days across the east coast due to a SPOF.

Amazon is one of the countless big companies that have had to tackle SPOFs.

By the time you finish this article, you’ll have a solid understanding of SPOF triggers, identification, and prevention.

What Does Single Point of Failure Mean?

Before we take a closer look at what is a single point of failure, let’s start with the basics.

A definition of single point of failure in IT is when a single component of a system causes the entire system to fail.

To help you better grasp this concept, let’s assume you build a tower out of a stack of cards.

Now, once your tower is complete, remove a card—any card will do.

What happens?

The cards fall, right?

That’s precisely how SPOFs work.

Single point of failure happens when one malfunctioning element causes the “tower” (and in the case of IT, the system) to crash.

Here’s an interesting fact: the concept of a single point of failure has expanded outside the IT and engineering world.

For example, architects may refer to a SPOF if a bridge falls down due to a single component.

What Are Examples of a Single Point of Failure?

Now that we’ve simplified a SPOF using a deck of cards let’s look at some examples of SPOFs in the IT industry.

When identifying a single point of failure system in IT, there are three broad categories to consider:

  • Hardware failures
  • Software failures
  • Database corruption

SPOFs in hardware can include power supply issues, network failures, and malfunctioning of the storage subsystem.

On the other hand, software failures involve issues with the Directory Server or Proxy Server.

Examples are problems with the cache, replication overload or synchronicity, and CPU constraints.

Regardless of the SPOF instigator, the risk of a single point of failure is that your system will crash.

For this reason, you must secure your data with a data center or online cloud.

SPOF is so common in IT that larger companies often have a single point of failure person in charge of assessing risks. 

SPOF is on The National Center for Biotechnology Information’s mind, too; they state that SPOFs are something Smart Cities must avoid. 

The Case of Delta Airlines

Flights cancelled displayed on an information board.

If the information above sounds too technical, let’s bring it back to a real-world example—Delta Airlines.

In 2016, a power failure occurred at Delta’s data center in Atlanta.

The issue forced over 700 flight cancellations across the globe.

Delta had redundancies in place in the form of backup servers, but the power failure was so extreme that some of their systems didn’t switch to the backups.

Now, had Delta used an online cloud server rather than a private data center, this issue wouldn’t have happened.

Or, at the very least, it would have offset the chances of it happening.

But the single point of failure in this data center case study proves how even large companies can struggle with SPOF.

It also highlights cloud servers’ benefits since their data most likely would have been spread out among various vendors.

Therefore, a power outage in one area wouldn’t affect all of the cloud servers.

How Cloud-Based Servers Can Help With SPOFs

It’s undeniable—the cloud could have prevented Delta’s power outage situation.

But you may be wondering: what exactly is the cloud?

The cloud is a powerful online storage facility that both individuals and businesses use.

You can store and access data on the cloud, from laptops to tablets to smartphones.

A variety of businesses have their own cloud.

But as beneficial as it can be, like any piece of technology, it opens the opportunity for a single point of failure cloud computing issues.

For example, many video games, such as Sony’s PlayStation Network, offer their services on the cloud.

The benefits of this to both company and users are numerous, including instant updates.

However, by purchasing a video game or service connected to the cloud, users will be impacted if a SPOF occurs.

The International Journal of Science and Research (IJSR) recommends implementing a single point of failure process that includes redundancy and high-availability clusters.

High-availability clusters are a series of computers that work together for the benefit of server applications running smoothly.

In fact, IJSR’s research shows that 99.99% of outages are minimized with high-availability clusters.

How Do You Identify a Single Point of Failure?

Pensive colleagues reading business information on the computer.

Now that you know what a single point of failure is, you must be wondering how to assess a SPOF so that you can start fixing it.

Running a single point of failure analysis is the first step you should take when a SPOF occurs.

The analysis should be conducted by your IT team, as they know your system best.

They should start by documenting individual technical components of the system.

In other words, anything connected to your network should be noted.

Items that should be on this list include:

  • Service providers such as for your email and cloud storage
  • Network Infrastructure
  • Any storage devices and local servers you may use
  • The ISP

Ideally, this list should be prepared before a single point of failure happens.

But if you don’t have one in advance, then know that you should note each technical component’s age and status.

You’ll then want to assess which of the components don’t have redundancy.

Work through them until you find the culprit of your SPOF.

The best part?

You may find opportunities for improvements with other components that haven’t yet undergone a SPOF.

That may not sound like such a great thing to you now, but we’re sure that your future self will thank you.

Can People Cause a Single Point of Failure?

You may not want to read this, but people are some of the most common instigators of causing a SPOF.

Now, it’s not to say that your employees are intentionally programming a single point of failure.

It could simply be that a person made an innocent input mistake.

But there’s no doubt about it—disgruntled employees could have malicious intent.

You may think that this could more commonly happen at larger companies.

But in fact, employees at small companies often have access to passwords and systems that larger companies would have separate employees managing.

So, what’s one of the best ways to prevent a human-caused SPOF?

You should develop a single point of failure company policy that involves password changes.

Did your employee quit or get fired?

Change the passwords they had access to.

How about an employee promotion or demotion?

Change the passwords for anything they no longer have access to.

Changing passwords offers businesses a wealth of benefits, so you’ll be promoting a more secure company environment, SPOFs aside. 

How Do You Overcome a Single Point of Failure?

Now: You’re probably already wondering how to overcome the problem of a single point of failure.

The answer is in the concept of redundancy.

Redundancy is the act of duplicating hardware and software components—making them redundant—so that you always have a replicated version.

Doing so with directory servers is the most effective use of redundancy.

There are advantages and disadvantages to implementing redundancy. Let’s take a look at both.

Advantages of Implementing Redundancy

  • Typically more economical than fixing a SPOF without a redundancy
  • Implementation is easy
  • Requires little management

Disadvantages of Implementing Redundancy

  • May offer poor Availability during a failure
  • Can have slow response times

What’s the bottom line here?

There’s no single point of failure software or redundancy that can guarantee a SPOF won’t happen.

However, implementing redundancy strategies in your business can help mitigate the impact of a SPOF.  

How Can Redundancy Help With a Single Point of Failure?

You already know that the three broad categories a single point of failure can affect are hardware, software, and database corruption.

Now, you might be wondering: how exactly does redundancy fit into this?

Hardware is the most labor-intensive SPOF.

Since you’re dealing with a physical mechanism that’s malfunctioning, you’ll need someone to repair the part with the redundant piece you have on hand.

The good news?

It gets easier after that.

If you have a software-related SPOF, typically in the form of a directory server or directory proxy server failure, the server should restart automatically. That’s it.

No other intervention is needed on your part.

When it comes to database corruption, redundancy is often able to overcome this on its own.

However, it depends on the architecture and is something that should be managed by an IT professional. 

Bottlenecks and Redundancy

A bottleneck is a concept that’s linked to redundancy in an attempt to avoid a single point of failure.

How does this work, you ask?

Let’s say you’ve done your homework and have redundancies in place.

No doubt, you should feel good about this.

However, if the redundancies have to kick in, a process might become too slow (or “bottlenecked”), assuming that those redundancies require processing a lot of data.

You want to avoid bottlenecks because they can negatively impact the entire operational system.

Before you worry too much, know that fearing bottlenecks isn’t a reason to avoid putting redundancies in place.

Instead, it’s something to discuss with your IT team.

They’ll be able to tell you if your redundancy requires a high level of data processing.

When Security Doesn’t Work With Avoiding SPOFs

Here’s some surprising news: single point of failures in servers can happen with security software too.

That’s right—the very tool that’s supposed to aid you in avoiding a SPOF can cause it.

The reason?

Security tools rely on the internet, and anything connected to the internet is susceptible to attacks and power outages.

Additionally, they can undergo NIC failure, meaning that they may get confused about blocking good traffic and permitting bad traffic.

To safeguard yourself from a SPOF as a result of a security threat, you should aim for redundancies in your security software.

You might be wondering: what kind of security software should you purchase?

Intrusion prevention systems, web application firewalls, and advanced threat protection are all variations of security software.

Do your research, read reviews, and pick the one you feel most comfortable with that fits within your budget.  

Logging Into Company Systems and SPOF

Nowadays, it’s common for businesses to allow their users to login onto their company system through Google or Facebook.

Here’s the truth—using Google and Facebook logins to set up profiles on other company websites is an attractive option for new users.

Let’s face it: none of us need yet another password to add to our already hefty list.

But there’s a downside to this convenience. 

If Google, Facebook, or any other provider faces a SPOF, your users will be subject to the issue. 

As a best-case scenario, they won’t be able to access your system until the SPOF is resolved.

In a worst-case scenario, their private information could be compromised.  

If you’re concerned about logins with other providers, you may want to encourage your users to establish a two-factor authentication.

Two-factor authentication is an option offered by companies like Google.

This way, should a SPOF affect a login provider you use, your users with two-factor authentication may have less of a chance of their information being compromised. 

Single Point of Failure Business Outcome

SPOF is something you want to avoid, but it’s not an excuse to avoid technology dependent on systems that can result in SPOFs.

According to Medium, businesses like Google, Instagram, and the Internet as a whole are managed in full or part by single systems without an alternate option like redundancy.

So, while you should actively implement SPOF risk management strategies, know that in some instances, for certain systems, even the big guys aren’t too concerned about it.

Intentional SPOF

Up until now, we’ve cast SPOF in a bad light—and for a good reason, wouldn’t you say?

But here’s the thing: occasionally, a SPOF is intentional.

How so?

Take, for instance, passwords to log into a laptop.

Passwords are designed to allow the right user(s) into it.

Or, to look at it another way, passwords are a single point of failure network for people who shouldn’t be accessing the system.

When it comes to personal laptops, you naturally want to keep the wandering eyes of your family off your screen.

But think about the implications of intentional SPOFs for high-security jobs.

Intentional SPOFs are essential to them keeping information classified.

How Do You Prevent a Single Point of Failure? (3 Things)

We’ve already covered redundancy, so you might be wondering: how else can you prevent a SPOF?

According to research conducted at Southeastern Oklahoma State University, three factors go into preventing a SPOF.

They include:

  • Risk management
  • Effective response
  • Prevention 

Let’s take a look at each in more detail.

#1 Risk Management

The idea behind risk management is that you identify possible IT SPOFs.

Risk management is an active role, looking for issues before they result in a system shutdown.

We’ll talk in detail about this in the next section.

#2 Effective Response

People on a SPOF team should practice flexibility and adaptation.

How a business responds to SPOF impacts how quickly it’ll be successful and helps them minimize lost profit.

#3 Prevention 

The concept of prevention differs from risk management because it’s the study and implementation of lessons learned.

It assesses everything from a single point of failure in project management to why the SPOF occurred.

Together, risk management, effective response, and prevention knowledge support business continuity without a single point of failure.

It results in higher profits and better quality IT systems.

What Are Risk Management Steps to Take To Minimize SPOF Risk?

When it comes to a single point of failure risk management, there are some steps you can take to minimize SPOF risk.

They include the following:

  • Install a secondary firewall or switch
  • Observe your network
  • Secure your data

These strategies are designed to protect your business’ data should a SPOF occur. 

When it comes to an IT single point of failure, a common instigator is network architecture.

In other words, your business is connected online via a solo router, firewall, or switch.

You’ll be happy to hear this: modern-day firewalls come with a High Availability option.

High Availability means that if your primary firewall malfunctions, the secondary firewall will automatically kick in.

Another SPOF risk management strategy is monitoring your network.

The concept behind observing your network is simple, including concepts such as checking the strength of passwords, how often passwords are updated, and identifying any equipment an unauthorized user could access.

Finally, in the event of a SPOF, you’ll want to know that your data is secured. Let’s take a closer look at this.

Microservices Architecture

When assessing how to reduce the chances of a SPOF, it’s a good idea to consider microservices architecture.

Essentially, microservices architecture distributes parts of systems in different places.

As you work with your IT team or consultant, they may recommend the following network options:

  • Open Shortest Path First (OSPF)
  • Shortest Path Bridging (SPB)
  • Intermediate System to Intermediate System (IS-IS)

Regardless of the system you choose, multipath routing is an excellent option for quickly moving information around within a computer network and safeguarding your company from SPOF.

Is SPOF Prevention Necessary for Small Businesses?

If you’re reading this article as a small business owner, you may be thinking: is it worth it to spend time and money on SPOF risk management?

Here’s the truth: multi-million-dollar companies will implement more SPOF prevention than small businesses, and businesses of any size with a 100% online business model will want more SPOF prevention than a business that doesn’t.

When it comes to SPOF for small businesses, these are the most important—and cheapest—SPOF strategies to keep in mind:

  • Ensure your data is backed up on a different device or cloud software.
  • Have two security programs in case one fails.
  • Ensure you have a quality WiFi provider and a backup modem.

We understand that a single point of failure risk for small businesses isn’t comparable to larger companies.

Your IT guy might also be your receptionist and delivery person, assuming you’re lucky enough to have a tech-savvy employee.

And that’s okay.

Sometimes it just has to be alright to cross bridges when you come to them.

Securing Your Data

SPOFs are stressful enough without the added worry of wondering whether or not your business’ data has been compromised.

You might be wondering: what’s the best single point of failure backup?

The best data backup center varies from company to company as part of their single point of failure management plan, but an essential factor to consider is location.

For example, if you’re in an area prone to hurricanes or tornadoes, you’ll want to make sure the data center you choose is designed to withstand them.

Data centers should be equipped to handle power outages, but it’s important to verify this too.

The bottom line here is that securing your data won’t prevent a SPOF, but it’s a way for you to rest easy at night knowing your company and clients’ information is secure should a SPOF happen.

The Other Side of Risk Management

Remember the Amazon example we gave at the beginning of this article?

At the time, it was devastating for DynamoDB data to malfunction.

But this pushed Amazon to improve its system.

Three years later, Amazon developed an encryption at rest for its DynamoDB database.

What did this mean for users?

That any service with DynamoDB integration instantly benefited from the upgrade.

So, while it’s crucial to eliminate a single point of failure and manage risks, this example proves there can be benefits to keeping technology limited to a single system.

What’s the bottom line here?

You should work with your IT team to develop a risk management plan conducive to your goals and budget.

IT Audits

Ideally, you should aim to audit your IT system once per year to reduce the chance of a SPOF.

You might be wondering: what is a single point of failure in regard to prevention via auditing?

The answer might surprise you.

Below are some key things you should look out for during your annual audit:

  • Ensure your backup power supplies aren’t expired. Do you have a generator? Make sure you have gasoline on hand.
  • Check the physical infrastructure of your hardware. Such a check includes cables and cords to make sure they aren’t frayed.
  • Review your IT point of contact. Ensure they have the resources they need to perform their job as best as possible.
  • Update the records you keep of hardware and software that’ll be your reference if a SPOF happens. At the very least, their age should be increased by a year.
  • Reach out to your internet, Security, and other providers. Educate yourself on any changes they’ve made, and take advantage of any improvements they may be offering to their users.

One of the cheapest ways to approach the potential for a SPOF is to put time and money into avoiding it.

So, start a good habit now by penning annual IT audits into your calendar.

Why Is 100% SPOF Prevention Difficult?

In a perfect world, we’d always have a spare roll of toilet paper on hand, our joints would stay as limber as when we were kids, and planes would never get delayed for mechanical repairs.

But here’s the thing—no matter how much toilet paper you have, how healthy you eat, or how many routine mechanical checks they do on planes, something will always go wrong.

The same goes for SPOF.

You can make plans, have a trained IT team, and have redundancies in place, but someday something bad is bound to happen.

And that’s okay.

It’s so okay, in fact, that it’s standard advice not to go down the rabbit hole of chasing every redundancy you can prepare for.

Doing so can be costly and more time-consuming than fixing a SPOF when it arises.

We’re talking about minor redundancies here, not the big ones like security and data backup. 

What Is the Cost of a Single Point of Failure?

What’s the good in knowing what a single point of failure is without understanding its cost implications?

Unfortunately, you won’t be thrilled with the answer. 

It’s impossible to say how much it can cost to fix your single point of failure.

The reason being is that it depends on what hardware, software, or database corruption has occurred. 

Other factors include your company’s size and whether or not your IT team—if you have one—can fix it without needing outside assistance.

The good news is that prevention is typically less expensive than dealing with a single point of failure database after it’s already occurred.

Therefore, you should focus on developing redundancies.

Also, make sure to keep a list up-to-date with the detail of your technical components and whether or not they have redundancies.

Small preparations like these will go a long way in reducing the stress should a SPOF ever occur in your business.


  • Theresa McDonough

    Tech entrepreneur and founder of Tech Medic, who has become a prominent advocate for the Right to Repair movement. She has testified before the US Federal Trade Commission and been featured on CBS Sunday Morning, helping influence change within the tech industry.

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