BP_088_en.md

Adapt quality of service and availability level

Identifiers

GreenIT	V2	V3	V4
501	86	88

Categories

Life cycle	Tiers	Responsible
4. Production	Datacenter	System Administrator

Indications

Priority	Implementation difficulty	Ecological impact
3	2	4

Saved resources
Power Consumption

Description

Quality of service (QoS) and service level agreement (SLA) must be determined with the users of the digital service. For example, it is unnecessary to host services in a very high availability data center (Tier IV) if users accept an availability rate lower or equal to 99% for a non-critical service. With equivalent energy efficiency, the higher the availability of the data center hosting the website or online service, the higher its overall environmental footprint. Notably because everything is redundant and active: two power supply chains, two cold production and distribution chains, etc. It is essential to avoid overqualification. It is recommended to apply a quality of service based on the sufficient availability level instead.

Example

Despite having hundreds of millions of users, Web giants do not offer very high availability level of Tier IV type. Data is redundant on at least one other server in another data center. If a server fails, users will be automatically routed to the backup server. This action may take a few seconds, which is acceptable and almost imperceptible for end-users.

Validation rule

The number of ...	is equal to or less than
increases in the availability level while the current level is sufficient	0