3. Orchestration (Infrastructure Scaling) : 3.1 Scaling Localization
   
3.1 Scaling Localization
Depending on the complexity and architecture of the application service, there are several approaches to scaling.
*Fixed scaling – Scale where the bottlenecks typically occur.
*Scale everything – Scale out the entire environment with each scale event.
*Intelligent scaling – Scale where the resources are needed.
Table 2. Scaling Modality Benefits and Drawbacks
Scaling Mode
Benefits
Drawbacks
Fixed Scaling.
Simplicity.
*Can create bottlenecks in other areas of the service.
*Bottlenecks not within the fixed scaling components are not addressed.
*Scaling might not address the problem, and if not managed properly, this can result in a runaway scaling event.
Scale Everything.
Simplicity.
*Can result in over-provisioning in some tiers of the service.
*Can be far more time consuming during the orchestration phase of scaling out.
*Can be more complicated than a fixed scaling approach due to database configuration and synchronization challenges.
Intelligent Scaling.
*Adds capacity where it is needed every time.
*Scaling out across tiers and components dynamically avoids creating new bottlenecks.
*Excess capacity is not added where it is not required.
Complexity.
 
In the context of scaling, the scale remediation can scale out, scale up, or a combination of both depending on the level of complexity within the system. Make scaling design decisions based on prior knowledge of the application or services scaling characteristics.