Sampler
See also Sampler reference
The Sampler component in Aperture is designed to manage the load at a Control Point by allowing only a specified percentage of flows at random or by sticky sessions. This is useful for controlling the load at a feature inside your service for performing controlled tests. It achieves this by either acting as a stateless filter or a sticky filter, depending on the provided configuration.
Stateless Filter
When the label key is not specified, the Sampler acts as a stateless filter. In this mode, it selects a percentage of flows randomly. This is useful when you want to control the overall load on a control point without focusing on specific sessions or users.
Sticky Filter
If a label key is specified, the Sampler acts as a sticky filter. In this mode, it ensures that a series of flows with the same value of the label key get the same decision, provided the accept percentage remains the same or higher. This is useful when you want to maintain consistent behavior for specific sessions or users.
Dynamic Configuration
The Sampler supports dynamic configuration by specifying certain label values to be accepted by the flow filter, regardless of the accept percentage. This allows you to make exceptions for specific sessions or users, granting them unhindered access to a control point.
Flow Selector
The Flow Selector is responsible for determining the service and flows at which the Sampler is applied. By configuring the Flow Selector, you can control which parts of your service are affected by the Sampler.
Accept Percentage Signal
The Sampler component takes an accept-percentage input signal, based on which it decides the percentage of flows to accept. This gives you fine-grained control over the flow of requests to a control point, enabling you to achieve the desired balance between load and performance.