High Availability in Hosting Online-Shops

Learn in this blog post how to keep your online shop always accessible and performant. Additionally, we share insider tips on how we ensure 99.99% availability.

High Availability in Hosting Online-Shops

The world of e-commerce is highly competitive, and customer expectations are higher than ever. Agencies and online shop operators know that any downtime or delay in online business can directly result in lost revenue and disappointed customers. But how do you ensure that an online shop runs smoothly at all times? This is where our concept of high availability comes into play.

What Does High Availability Mean?

High availability refers to systems designed to remain continuously operational despite failures or downtimes. The goal is to minimize downtime and ensure customers can access the online shop at any time. This is particularly important for e-commerce websites, as any period of downtime can potentially lead to revenue loss and a negative impact on brand image.

Why Is High Availability Important?

For online retailers and agencies, every minute of downtime can mean significant financial losses. A study by Gartner showed that the average cost of IT downtime for large companies can be around $5,600 per minute. Even though these figures vary for smaller companies, the basic message remains the same: downtime costs money and damages customer trust. Additionally, online shop owners should keep the following points in mind:

• Maximum Uptime: A highly available online shop minimizes downtime. Every moment a shop is offline means potential revenue loss.
• Customer Satisfaction: Customers expect a seamless shopping experience. Unexpected downtimes can erode customer trust and drive them to competitors.
• SEO Benefits: Search engines prefer websites that are reliable and load quickly. Downtimes and slow loading times can negatively impact rankings.

Key Questions for Ensuring High Availability

To ensure the high availability of your online shop, you should ask yourself some essential questions:

• How long can my shop be offline before it becomes critical?
• Which components of my system are most prone to failures?
• What technologies and architectures can I use to minimize downtime?
• How can I improve the reliability and redundancy of my hosting?
• What role do regular monitoring and maintenance play in ensuring high availability?

Strategies for Ensuring High Availability

Here are some of the most important strategies for increasing availability:

Redundancy and Failover Mechanisms

A basic strategy for increasing availability is to implement redundancy. This means having multiple copies of critical system components so that if one component fails, another can take over. This can be done at various levels:

• Server Redundancy: Use multiple physical or virtual servers that provide the same services. If one server fails, another can take over.
• Database Redundancy: Use read replication or multi-master replication to ensure continuous access to databases.
• Network Redundancy: Use multiple internet connections and load balancers to avoid network bottlenecks.

Load Balancing

Load balancers distribute traffic evenly across multiple servers. This helps avoid overloads and contributes to redundancy. In case of a server failure, the load balancer can automatically redirect traffic to the remaining servers.

Database Clustering

Database clustering involves multiple database instances working together to increase availability. Requests can be directed to multiple nodes in the cluster, reducing the likelihood of failure.

Geo-Redundancy

Geo-redundancy means hosting data and services at multiple geographic locations. If one location fails (e.g., due to natural disasters), another location can take over operations. This is especially important for internationally operating online shops.

Regular Backups and Disaster Recovery

Regular backups are crucial to prevent data loss. A comprehensive disaster recovery plan ensures that in the event of a major failure, data can be restored and operations resumed quickly. More information on backups can be found in our blog article “A Guide to Backing Up Web Applications”.

Technologies and Tools Supporting High Availability

Various technologies can support high availability:

• Containerization and Orchestration: Containerization allows applications to run in isolated environments, improving portability and scalability. Tools like Docker simplify container management, while orchestration solutions like Kubernetes can automate deployment and management.
• Content Delivery Networks (CDNs): CDNs improve the availability and performance of websites by delivering content through a network of globally distributed servers. This reduces latency and ensures users always have access to the latest content, even if parts of the network fail.
• Monitoring and Automation: Regular monitoring and automation are essential to detect and resolve potential issues early. Tools like Nagios, Prometheus, and Grafana offer comprehensive monitoring and alerting functions. Automation tools like Ansible and Terraform facilitate configuration management and infrastructure deployment.

Implementing a High Availability Setup: An Example

To put theoretical concepts into practice, let's look at an example of implementing a highly available online shop running on a platform like Shopware or Magento.

Step 1: Architecture Design

Design an architecture that considers redundancy and scalability. This includes multiple web servers in a load-balancing configuration, a database cluster with MySQL in a replication configuration, and geo-redundant data centers.

Step 2: Technology Selection

Select technologies such as load balancers for traffic distribution, containerization with Docker and Kubernetes, infrastructure, and the use of CDN services.

Step 3: Implementation

Set up the infrastructure using cloud services and implement Docker containers for the applications. The database is provided in a highly available configuration, and a CDN is configured to improve performance. This includes:

• Implementing the CDN
• Setting up the infrastructure
• Deploying the web servers
• Database setup
• Configuring the load balancer
• Implementing the CDN
• Monitoring and automation

Step 4: Testing and Optimizing

Conduct comprehensive tests, including failure simulations and load tests, to ensure the setup meets requirements. Based on test results, adjustments are made to further optimize performance and availability.

After implementation, it is crucial to conduct thorough tests to ensure the high availability setup works as expected. This includes:

• Failure Simulation: Testing how the system responds to the failure of individual components.
• Load Testing: Checking how the system handles peak loads.
• Monitoring Check: Ensuring all monitoring and alerting systems are functioning correctly.
• Testing and Optimizing: These measures help ensure a robust and highly available infrastructure for operating an online shop without favoring specific providers.

How Does maxcluster Ensure High Availability?

At maxcluster, we guarantee our customers 99.99% availability. High availability means an IT system is available and reliable almost 100% of the time, avoiding or minimizing downtime. To keep complexity manageable for our customers, we implement high availability at the server level rather than the service level. This means that a failure of the underlying hardware of any of our cluster servers is secured by a failover server. This server is synchronized with the live server once a day and can quickly replace it in case of a failure.

However, if an individual service is unavailable, our monitoring detects and corrects it immediately. While daily synchronization is sufficient in most cases, it would lead to significant gaps in the order history for database servers. Therefore, we use a shared file system to ensure the database is synchronized with the failover server in real-time.

Conclusion

High availability is a critical aspect of hosting online shops. By implementing appropriate strategies and technologies, agencies and online retailers can ensure that their online shop is always accessible, thereby avoiding revenue loss and negative impacts on brand image. Whether through redundancy, load balancing, containerization, or the use of cloud services – the possibilities are numerous and should be carefully tailored to the specific requirements of the shop.

By following the best practices described in this article, you can significantly improve the high availability of your online shop and thus secure the long-term success of your e-commerce business. With the managed clusters provided by maxcluster, this work is taken care of for you.

Published on 20.06.2024 | High Availability in Hosting Online-Shops | DW