A potential failure and the resulting business downtime is a real nightmare for business. Is there any way to ensure the systems are as reliable as possible? The solution may be the use of the cloud, especially high-availability services. One of the key aspects of IT disaster recovery is ensuring operational performance in case of major unwelcome events. It is done by providing the system with sufficiently redundant components, such as multiple servers, network connections and storage systems. The solutions labeled as High Availability (HA for short). High availability refers to those systems that offer a high level of operational performance, including load balancing, high availability clusters and fault tolerance. Let’s take a closer look.
High Availability – what is it?
In some industries, disruptions in access to services may prove catastrophic, not only for financial reasons. Ensuring business continuity, requires reliable systems. High-availability infrastructure is configured to deliver quality performance of critical systems and handle different loads and failures with minimal or zero downtime.
The definition of high availability assumes that a given service should operate without interruption for a specified period of time, even in the event of a failure. This will remain unnoticeable to the user because the entire system is well prepared for such events. If a single server or its components go down, another machine in the area automatically takes over. This is the power of distributed cloud services architecture.
Google Cloud zones
Google Cloud Platform (GCP) is spread across the globe. It has been divided into 32 geographical areas (regions), within which there are a total of 97 availability zones. Each region has at least three zones that house the cloud service provider’s data centers.
Machines often work together as a cluster. This means that the servers share the load between themselves (via load balancing) and constantly synchronize data, behaving as one server. When one instance or data center is unavailable, another immediately takes over the traffic and service provision. Instances can also auto-diagnose and self-heal.
It is worth noting the recent launch of the first Google Cloud region in Central and Eastern Europe. The Warsaw region shortens not only the access time to cloud services. Increases the level of awareness and availability of cloud services for local businesses.
High Availability and virtualization
High availability is relatively easy to achieve using virtualization. We connect virtual machines running in the cloud into clusters (just like physical devices, but this operation reduces costs, increases the pace of implementation and makes better use of available resources).
High availability clusters
High availability clusters are groups of servers that support applications that are critical for business operations. In the event of a failure of one of the machines, another one takes over its operation immediately. This way it ensures the system will operate continuously, increasing its operational performance.
HA cluster implementations attempt to build redundancy into a cluster to eliminate single points of failure, They include multiple network connections and data storage, connected redundantly via storage area networks.
High Availability software – databases
One example of a Google Cloud Platform service where there is a need to ensure high availability is the Cloud SQL database, which allows to set up the so-called regional instance. This means that the database is available in two zones, and any change in content is accompanied by immediate synchronization.
Cloud SQL databases
In Google Cloud Platform, the Cloud SQL database has support for external physical data carriers (so-called Persistent Disks). This way, critical data will remain available in the event of a failure of the virtual machine or even the entire physical server.
