Reliability counts: Why availability zones in the STACKIT Cloud are crucial
Whether administration, healthcare or industry – digital applications must be available around the clock in real time. At the same time, processes must continue to run stably even in the event of technical faults, as reliably and securely as possible and within the EU. But what happens if a data center is suddenly unavailable?
The answer lies in the architecture of modern cloud infrastructures. Stable services require more than powerful servers: they need systems that react automatically in the event of failures and intelligently distribute resources across multiple server locations. This is where availability zones come into play.
STACKIT relies on a regional model with maximum reliability, data availability and digital sovereignty: 100% European, highly scalable and technically sophisticated. A real alternative to international hyperscalers.
Key terms relating to availability zones
- Availability zone (AZ): An independent data center network with a separate power supply, cooling and network connection. An AZ can consist of one or more data centers and is part of a region. The aim is to isolate local failures from each other and thus increase reliability.
- Region: A geographically defined unit, which at STACKIT consists of at least three availability zones. Regions enable a geo-redundant distribution of cloud resources across multiple locations.
- Metro setup: An operating model in which virtual machines and data are automatically mirrored across multiple AZs within a region. Even if one zone fails, the service remains available – a central element of highly available cloud solutions.
- Single availability zone: In this setup, a resource is assigned to a single availability zone. If this zone fails, this affects all applications operated there. This model is suitable for less critical workloads with a short service life.
- Cloud resources: Virtual machines, storage solutions, networks and services that are provided and operated within an AZ or distributed across multiple zones.
- Data availability: The ability of a system to access data at all times – even if individual components or entire availability zones fail.
- Availability Zone Services: Special STACKIT services that are specifically designed for use in multiple AZs – such as block storage with mirroring or zone-redundant network concepts.
- Multi-region architecture: A cloud architecture distributed across several regions that is designed for international scaling, regulatory requirements and additional redundancy. This architecture complements the zone concept on a global level and offers customers maximum flexibility.
- API solutions: Programming interfaces that can be used to automatically create, manage and monitor cloud resources – including targeted allocation to specific availability zones.
STACKIT availability zones: Advantages at a glance
Availability zones are the safety net of modern cloud infrastructures. At STACKIT, they go far beyond technical redundancy: they create the basis for maximum availability, secure data storage and digital sovereignty. Below you will find the most important advantages from which you can also benefit:
1. reliability through physical separation
Each availability zone consists of an independent location with its own power supply, cooling and network connection. If a zone fails temporarily – for example due to a power failure or a local event – instances and information in the other zones remain accessible. This avoids single points of failure and reliably secures business-critical processes.
2. maximum data availability and fast recovery
Cloud resources can be created and replicated synchronously across multiple zones. In the event of a failure, affected instances are automatically restarted in another zone. This significantly shortens both the recovery time objective (RTO) and the recovery point objective (RPO) – a key advantage for digital services in the public sector, healthcare or retail.
3. low latency – even with distributed architecture
STACKIT positions its data centers so that they are geographically close to each other but physically separated. This enables very low latencies between the zones. For latency-critical processes, this results in an optimal user experience with high resilience.
4. scalability through flexible resource distribution
Applications can be distributed across multiple infrastructure units in a targeted manner. In the event of peak loads or outages, traffic is automatically redirected – without any manual intervention. The infrastructure scales dynamically and keeps performance stable even when requirements fluctuate greatly.
5. sovereignty, data protection and compliance – 100% EU-based
All STACKIT availability zones are located in Germany and Austria. This means that all data, services and cloud resources are subject exclusively to European law. Our data centers have various certifications such as ISO 27001 and C5. They therefore guarantee the highest security standards – essential for anyone working with sensitive information.
6. full control and individual zone selection
You can use the STACKIT portal or the API to precisely control the availability zone in which instances, storage or networks are created. This enables tailor-made architectures – for example to comply with local specifications, to optimize latencies or for resilient multi-zone deployments.
7. plannable maintenance without service interruption
Updates and maintenance work can be carried out on a zone-specific basis. Applications remain active in at least one other zone – and your services remain available throughout. This not only increases operational reliability, but also reduces downtimes to a minimum.
How do STACKIT availability zones work in detail?
While international providers operate availability zones worldwide, STACKIT focuses on locations in Germany and Austria. As a result, customers benefit from maximum data sovereignty and GDPR compliance without having to forego the technical advantages of globally proven zone architectures.
STACKIT availability zones are physically separate locations, each with its own power supply, cooling and network connection. This isolation ensures that a failure in one zone has no impact on other zones within the same region. A STACKIT region usually consists of three or more such zones, positioned to operate geo-redundantly: far enough apart to decouple local risks such as power outages, natural disasters or network disruptions – and close enough to allow very low latency between the zones.
This architecture allows two basic operating models. In the so-called single setup, applications or virtual machines (VMs) are assigned to a specific zone. If this zone fails, the assigned resources are no longer available. The metro setup is different: Here, applications and information are automatically mirrored across multiple zones. If there is a fault or maintenance in a zone, the service remains online – without any intervention by the user. The metro setup significantly increases reliability and is particularly suitable for business-critical applications with high availability and business continuity requirements.
STACKIT availability zones in practice
Administration: Resilient citizen services in the metro setup
Digital administrative services such as appointment systems or online applications must be permanently available. In a metro setup with STACKIT Compute Engine, these services run in parallel in several availability zones. This ensures stable operation – even in the event of maintenance or the failure of an entire site. Citizens benefit from continuous availability, while the administration benefits from greater planning security.
Digital Health: High-availability diagnostic services with cross-zone storage
In the field of telemedicine, availability and data protection are equally important. STACKIT Block Storage with automatic zone mirroring enables continuous access to patient data, even in the event of technical faults. Data processing takes place exclusively in certified data centers within the EU and meets all relevant compliance requirements in the healthcare sector.
E-commerce: Scale dynamically during traffic peaks
When the web store is under high load, everything has to run smoothly. With an architecture based on multiple STACKIT availability zones, data traffic can be distributed automatically as required. Latency remains low and the shopping experience stable – even under high load. Scaling and reliability go hand in hand.
Practical tips for your entry into availability zones with STACKIT
Availability zones are used in many areas: from fail-safe processes to flexible scaling. To get the full benefit from the STACKIT architecture, it is worth planning carefully in advance. The following practical tips will show you what is important for implementation.
Define a zone strategy at an early stage: At the outset, consider which of your applications actually require high availability and whether a single or metro setup is suitable. For latency-critical services in particular, it can make sense to provide resources locally and distribute them in a targeted manner. A clear zone strategy creates the basis for stable services and efficient management.
Allocate cloud resources in a targeted manner: Use the STACKIT self-service portal or the API to provision instances, network and storage directly in the desired availability zone. This gives you control over your infrastructure and allows you to customize automated deployments to your exact requirements.
Think about redundancy and monitoring: plan for failure scenarios from the outset. Rely on automatic mirroring and monitoring that works across zones. This allows you to identify problems at an early stage, narrow them down and resolve them with minimal effort – regardless of whether they are technical faults or planned maintenance.
Keeping performance and costs in balance: STACKIT’s pay-as-you-go model allows for flexible cost control. Always select performance classes and setups based on actual requirements and optimize your infrastructure step by step. This ensures you have a powerful and economical cloud environment.
Prepare migration and integration carefully: If you want to transfer existing workloads to a setup, a staggered migration with prior testing is recommended. Check the reliability, analyze the latencies and simulate live operation to ensure a seamless transition and a stable environment later on.
Availability, sovereignty, foresight: Prepared for anything with STACKIT
Whether power failure, network disruption or maintenance window – those who rely on STACKIT availability zones remain capable of acting. The combination of geo-redundant regions, certified data centers and flexible setup options reliably protects your processes against outages.
Unlike global hyperscalers such as AWS or Microsoft Azure, STACKIT processes all information exclusively in Germany and Austria. This gives you full control over your data – sovereign, GDPR-compliant and 100% EU-based. This guarantees maximum sovereignty and legal certainty, without compromising on performance or scalability.
Whether you want to create a new instance, expand your infrastructure or secure critical applications: With STACKIT, you can lay the foundations for a cloud infrastructure that not only works today – but will continue to do so tomorrow.
FAQ – frequently asked questions about STACKIT availability zones
What is the difference between a single and a metro setup with STACKIT?
In a single setup, a resource is permanently assigned to a specific availability zone. If an outage occurs there, the resource is no longer accessible. With a metro setup, on the other hand, applications and data are automatically mirrored across at least two availability zones. This significantly increases reliability and ensures genuine high availability.
Can I specifically select an availability zone with STACKIT?
When using instances, volumes or a network, you select the desired availability zone in the STACKIT self-service portal or via API. This allows you to tailor your cloud resources precisely to your requirements – whether for performance, compliance or latency reasons.
How do latency-critical applications benefit from availability zones?
STACKIT regions are structured in such a way that the availability zones are geographically close to each other. This ensures extremely low latency with physical separation. Ideal for applications where response speed counts, without compromising on reliability.
