E-mail is one of the most popular communication mediums in the world. It has become a necessity for many organizations and businesses, as it is a cost-effective way to communicate with customers, suppliers, and partners. It is even more important that mail servers are reliable to deliver messages to their recipients successfully.
High-availability mail servers are characterized by their ability to provide continuous service even if there are hardware or software failures within the server environment. They provide redundancy so that if there were an issue with one server, another server would take over its load automatically.
With high-availability mail servers, organizations can ensure that their e-mail service is always available and accessible.
What Is Meant by High Availability?
High availability (HA) is a term used to describe the system’s ability to maintain its availability in the event of a failure. A highly available mail server ensures that it can continue to provide mail service even if one or more components fail.
High availability guarantees a specific availability level for a certain period (e.g., uptime of at least 99.99% in a year which means 4 minutes of downtime per month).
High availability frequently includes redundancy, but the terms have different meanings. High availability means that a system will be available no matter what. In contrast, redundancy means that several components can be replaced to keep things functioning in the event of failure.
High-availability systems are often made up of a group of loosely coupled servers with failover capabilities. This method is not flawless in any way; for instance, its high cost, which will be discussed next.
What Are the Benefits of High-availability Infrastructure?
There are many benefits to high availability. For example, it helps organizations avoid downtime by ensuring that the mail server is always online, and it also reduces the time required for recovery in case of a failure.
- The high availability of mail servers helps companies save money and time in the long run by providing a stable environment for their employees to work in, without worrying about e-mails not getting delivered on time or at all.
- High-availability infrastructure provides a reliable system that is able to keep functioning in the event of a hardware failure.
- High-availability infrastructure means that servers are able to automatically fail over to a secondary set of servers.
- The high-availability infrastructure allows for the load balancing of different workloads across multiple servers.
However, there are some disadvantages. High availability, for example, comes at a high cost because it necessitates more hardware resources and configurations than servers with lower levels of availability.
Do you need an HA infrastructure?
Whether you are a service provider offering mail server solutions to customers or an organization in need of a private collaboration platform, there are several instances where you might need high availability on your server.
For instance, if you are a service provider, part of your job is about assuring the high performance of the service you offer, and simply put, you can’t do that without a reliable HA system. Another example is the significance of “prime time” or other time-sensitive factors where the service’s availability is crucial. In the business world, your customers are only available during specific hours. Losing this potential can have serious financial consequences. Let’s say a large international company has one of its most lucrative selling points in the early morning hours, but if there is a system failure during that time, the business may lose an entire day’s revenue.
Whether the availability of your services is essential in running your business or potential downtime somehow damages your income, a high level of availability makes a significant difference.
What is the Obstacle to Achieving High Availability?
As previously said, obtaining high availability is costly because it necessitates more system resources for greater levels of availability unless smart optimization and approaches are used to achieve the same availability without duplicating the entire infrastructure.
Assume you’re evaluating various HA solutions for your infrastructure. Depending on the extent of your infrastructure, replicating all of it can be incredibly expensive. Consequently, different strategies are employed to achieve the same result with fewer resources, resulting in significant cost savings. A highly efficient HA solution addresses these shortcomings by using new approaches.
The answer to how much it costs to make a mail server highly available depends on many factors. The first factor is the hardware and software requirements. The second factor is the organization’s size and budget. The third factor is your tolerance against downtime, and finally, your IT skillset will also influence how much it will cost you to recover from failures quickly.
How Carbonio’s HA System Is So Cost-effective?
Zextras Carbonio HA system uses an account-based replication technology with a mesh structure. To better understand, consider the following example.
Let’s say you have three servers and four accounts. As the table shows, a working server is specified as active. Standby means that the account is replicated on that server. Considering this method, you can at least lose half of the servers without impacting the infrastructure.
| Account 1 | Account 2 | Account 3 | Account 4 | |
|---|---|---|---|---|
| Server 1 | Active | Active | Standby | Active |
| Server 2 | Standby | Standby | Active | |
| Server 3 | Standby |
The most noteworthy benefit of this technology is that it eliminates the need for replication of the entire infrastructure, resulting in significant cost savings.
The beautiful thing with Zextras Carbonio HA is that, depending on the size of your infrastructure and the capabilities of your stores, you may be able to bear losing several stores before considering the entire system to be at fault.
The infrastructure will be unaffected even if half of the servers are lost.
This also allows you to choose which accounts to be replicated based on their importance. Note that this method is not the same as having a backup; it seeks to have many copies on other servers which already exist.
Another important piece of Carbonio’s high availability system is its heartbeat monitoring system (which is still under development). The server uses the heartbeat to determine if the application is having problems. This technology predicts the server’s failure before it goes down and spreads CPU-intensive or disk-intensive loads, eliminating the need to rely on more resources by optimizing your usage.
Consider simply employing the replication technology explained before; if a server fails, everything will continue to function normally to avoid a halt. Even though the server is still up and running, it may not be available at times. For example, it replies too slowly or responds with metadata because of corruption in the data. As a result, having a component that tracks how quickly the server responds based on CPU or memory loads can assist prevent such delays, saving a lot of time, effort, and money in the long run!
Disclaimer: The heartbeat monitoring system is still under development to bring the best out of the Zextras HA system.