High availability, thought through
From redundant data centres to clusters and replication to failover in seconds: this is how centron keeps your services running. Most businesses have a backup – far fewer can say how long it would take to be operational again. Anyone who has to rebuild servers, network, access and applications by hand after a total failure needs days, even if all the data is there.
- Four levels, one decision – from a simple backup to a cluster that never makes the outage visible in the first place.
- Distributed operation since 2016 – backups and systems across several locations in Germany, by default in Hallstadt near Bamberg.
- A tested restart – test environments for recovery, billed by the minute.
- Certified to the BSI standard – ISO 27001 based on IT-Grundschutz and BSI C5 attestation.
Availability is built up in layers
True high availability is not a single product, but rather the interplay between infrastructure, architecture and processes.
Redundant infrastructure
UPS, emergency power systems, separate fire compartments and multiple redundant power connections – the physical infrastructure at our data centre in Hallstadt near Bamberg.
Highly available architecture
Managed clusters with load balancing, real-time replication and automatic failover keep applications online – even if individual components fail.
Contingency planning
cProtect replicates data every 15 minutes to a separate fire compartment within the Hallstadt data centre – with immutable data states and failover within seconds, even in the event of a ransomware attack.
Vigilant processes
24/7 monitoring with alerts and – in the case of managed services – proactive fault resolution by centron experts before users even notice anything is wrong.
Four levels of resilience
The difference between backup and restart only becomes visible in an emergency – and then it is too late to clarify it. The permissible downtime and permissible data loss per system determine which of the four levels is required.
1. Backup
The data is there, the restart is done by hand. Downtime: hours to days. Suitable for systems whose failure is bearable, such as test environments or archives. Implemented via cBacks.
2. Backup at a second location
The same backup, additionally at another location. Protects against events that affect the entire site: fire, flooding, prolonged power failure. Implemented via managed backup or S3 Object Storage.
3. Failover
A second system stands ready and takes over in the event of failure. Downtime: minutes. The switch-over can happen automatically or on instruction. Suitable for systems whose standstill noticeably disrupts operations – implemented with cProtect.
4. High availability
Several systems run in parallel; the failure of a single one goes unnoticed by users. Downtime: close to zero. The most elaborate and expensive level, sensible for systems without which no work is possible – as a managed cluster in the High Availability Pool.
How much uptime does your system require?
Not every application requires geographical redundancy – but every one requires a well-thought-out plan. During the high-availability consultation, we analyse the costs of downtime, define RPO and RTO targets, and design the appropriate architecture: from a pair of load balancers to cross-site replication.
- Needs analysis – Clarify downtime costs and objectives
- Definition of RPO/RTO as a basis for architecture
- A tailor-made solution From clusters to geographical redundancy
- Contractual SLAs to give you certainty in your planning
What belongs in a plan – and who is responsible for what
Test recovery without spare hardware: you restore a backup into a new ccloud³ instance, check that the application starts and the data is correct, measure the time actually needed and delete the instance again afterwards – only the time it exists is billed. The measured time almost always deviates from the planned time, usually upwards; that is precisely the value of the test. What is documented: date, restored system, time needed, problems encountered and the resulting changes to the plan – exactly what auditors and insurers want to see. The evidence is provided by the Trust Center.
| Item | Content |
|---|---|
| Prioritisation of systems | An order by importance for business operations. Without it, the restart follows technical effort rather than need. |
| Recovery objectives | For each system, the permissible downtime and permissible data loss. Both values determine which of the four levels is required and at what interval backups are made. |
| Responsibilities | Named persons responsible with deputies, plus availability outside working hours, including that of the service provider. |
| Restart procedure | The individual steps, documented in a form that can also be carried out by people who do not look after the system daily. |
| Test cycle | A fixed schedule for rehearsal. A plan without a documented recovery is no evidence in an audit; at least one recovery per year per critical system is customary. |
| Task | You | centron |
|---|---|---|
| Classification of systems and recovery objectives | entirely | advice on technical feasibility |
| Disaster recovery plan | creation and maintenance | provision of operational details |
| Applications and operating systems | configuration, application restart | managed service on request |
| Backup and recovery | definition of interval and retention | execution and provision |
| Platform and data centres | — | redundancy, monitoring, emergency management of operations |
| Recovery test | planning, execution, documentation | provision of the test environment |
| Evidence for auditors and insurers | inclusion in your own documentation | certificates with scope, BSI C5 attestation and TOM in the Trust Center |
The right centron products
High availability emerges from the interplay of these modules – combinable and extensible at any time. We work out the right configuration together with you.
- Replication every 15 minutes
- Failover in seconds
- Separate fire compartment
- Design and operation by centron
- Retention as defined
- Restores tested regularly
- Load balancing and real-time replication
- Automatic failover
- Operation and updates by centron
Availability, in black and white
These values are laid down in the service specifications and apply per calendar month. cProtect has no availability commitment of its own; the service follows the SLA of the infrastructure on which the failover system runs. For a highly available system, the High Availability Pool is therefore the foundation.
| Service | Value | Scope |
|---|---|---|
| ccloud³ VMs in the High Availability Pool | 99.8 % | per month · ccloud³ service specification |
| ccloud³ VMs in the Worker and Power Pool | 99.5 % | per month · ccloud³ service specification |
| Managed Server | 99.5 % / 99.8 % | Worker/Power Pool or HA Pool |
| Volumes and S3 Object Storage | 99.9 % | per month · service specification |
| Colocation network | 99.9 % | annual average · Colocation service specification |
| cProtect replication interval | approx. 15 minutes | cProtect service specification |
| Customised SLAs | by arrangement | Managed Cluster and Full Managing |
Frequently asked questions on high availability and disaster recovery
What do 99.5%, 99.8% and 99.9% availability mean in concrete terms?
Isn’t a backup enough?
What belongs in a disaster recovery plan?
What is disaster recovery as a service?
What is the difference between high availability and failover?
How do I achieve high availability for my application?
How much resilience does a medium-sized company need?
What happens if the production system fails?
How does cProtect work?
How far back in time can I go with cProtect?
Does a backup protect against ransomware?
Does cProtect protect me against cyber attacks?
How can I protect myself even better against cyber attacks?
What alternative to cProtect is there?
What does a geo-backup offer?
How often should a recovery be tested?
Where are our backups located?
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