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What is High Availability and Why Do You Need it?

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high availability

High availability describes systems or networks that can operate continuously, with minimal downtime, even during peak usage. The advent of 5G has made high availability more important than ever as it has significantly increased the volume, variety, and velocity of data flowing into systems. 


The goal of high availability is to provide continuous service with minimal downtime (The only devices that truly have ‘zero’ downtime are pacemakers and security devices built into nuclear weapons.) This means that if one component fails, another can immediately take over its function without materially interrupting service to users of the system. High availability also requires the ability to detect when one or more components have failed, and then take corrective action to get them back into service.


The level of high availability to be provided to customers is defined in SLAs (“Service Level Agreements”) in quantifiable terms, including allowable downtime, which in the 5G world is virtually none. 5G networks—including the business support systems (BSS) providing such critical functions as charging and policy—must provide 99.999%, or “five nines,” of data availability annually. This equates to just six minutes of unscheduled downtime per year. 

Two things you should know:

  1. Most internet companies measure it per user, per year. So a company with a million users could have a single user down for a year and still claim to be ‘five nines’ compliant.
  2. Almost all vendors pretend the stack below them is 100% reliable when you ask them what their SLAs are.


High availability is critically important for businesses because it ensures that they are always able to provide services and products without any disruption, leading to better customer retention and reducing churn. 

As more and more things we use become more and more dependent on continuously being connected to something somewhere else, high availability becomes ever more important. As we get more and more connected, the costs of downtime become higher and higher. 

The business stakes get even higher when considering the vast new business opportunities and new enterprise applications that 5G makes possible. The more data there is to lose, the more important it is to keep your systems up and running. 

Seizing the full business potential of 5G requires data to be immediately available, resilient, and consistent, regardless of a user’s geographic location. Data center failure and data loss caused by unresolved data conflicts and cyber attacks simply can’t happen because they are too costly. 

In short, being able to provide high availability positively impacts:

  • SLAs
  • Customer relationships
  • Data security
  • Brand reputation

All of those combined have the potential to sink or save a business. 


Achieving high availability requires both local redundancy and geo-replication. Local redundancy means there are backup components in case one breaks down, while geo-replication duplicates data across multiple physical locations so the data can survive the loss of a geographical location.

However, achieving high availability in a 5G-enabled world isn’t easy. Failover solutions, redundancy, and network load balancing require a certain level of internal expertise and resources to execute correctly, and if your data platform doesn’t support high availability, you will soon find your TCO soaring as you add-on tech stack components to meet increasingly stringent availability SLAs. 


The Volt Active Data Platform was designed to ensure high availability that allows business continuity even in the face of hardware failures. 

Volt Active Data achieves high availability for 24x7x365 operations very simply and economically through automatic intra-cluster and inter-cluster replication. Incoming requests are stored on multiple physical disks on different servers before the requests are processed, which means that the loss of a single server will have minimal impact, as the survivors will be fully up-to-date. If needed, these writes can be synchronous. This provides durability against single-node failures.

Volt has customers in production with triple-active cross data center replication for geographically distributed resiliency to support 5G-grade quality of service, and Volt will soon be certifying four-way replication. While many data platforms and database technology companies offer some form of cross data center replication, not many offer true active-active cross data center replication, which means using two copies of a database at different physical locations, both of which can be changed in real time and both of which propagate their changes to each other. 

The nature of active-active systems allows the same piece of data to be changed in two or more places at once, but it’s how the resulting conflicts get resolved that determines the practicality and effectiveness of a given active-active solution. The naive solution is to let the most recent change win, but this means that the slightly-earlier completed transaction will vanish from the perspective of the outside world. Volt is the only data platform that captures conflict resolution events and makes them accessible, thus mitigating the negative side effects of conflict resolution.

With its patented Active(N) Lossless Cross Data Center Replication, Volt also adds the potential for a third data center to the equation, meaning that even if a data center goes down unexpectedly while another data center is undergoing planned maintenance, your apps will keep running and your system will stay up. 

Competent customer management, BSS, and revenue assurance in the age of 5G means no service failures. Your customers stay happy and loyal, and you head off fraudsters before they have a chance to wreak havoc inside your networks. With high availability, you reduce the negative impacts of downtime and implement automatic recovery from system failures, translating into better ROI and ultimately a more robust bottom line. 

David Rolfe