The key features in any data centre are redundancy and security.
Data centre network hardware / Redundancy
The network infrastructure is in most cases fully redundant. The data centre has multiple routers and multiple switches. Should hardware fail the built in redundancy ensures that any potential downtime is mitigated.
The data centre electricity supply is physically protected. In the event of power supply failure, UPS (Uninterruptible Power Supply) units automatically provide power. The UPS units provide power supply to racks until such time as the diesel generator takes over the supply of electricity.
The facility is multihomed. Meaning that the core network infrastructure and connectivity is supplied by multiple providers.
Access to the facility is controlled and monitored.
The data center is an extremely robust structure.
The building as a whole is alarmed. The data centre itself is also alarmed. The data centre is permanently locked, including when work is being undertaken inside.
The area is temperature controlled to provide the optimum environment for computer equipment.