DynamicHourlyLoadBalancer
The code provided defines three different 'director' configurations for handling load balancing across a three-hour tour. Each director is responsible for managing backend servers during a specific hour, and their configuration is structured using a random selection strategy. The purpose of these directors is to balance traffic across three backend servers (F_backend1, F_backend2, and F_backend3) by adjusting their weights for each hour.
### High-Level Purpose:
- **Load balancing:** The primary purpose is to distribute incoming requests to different backend servers, ensuring no single backend is overwhelmed during any phase of the three-hour tour.
### Functionalities:
1. **Directors:** There are three directors defined, each handling a separate hour of the tour. Each director operates with a random load balancing strategy.
- **First Hour:** F_backend1 is favored with a weight of 2, meaning it is selected twice as often as F_backend2 and F_backend3, which have a weight of 1 each.
- **Second Hour:** F_backend2 is favored with a weight of 2.
- **Third Hour:** F_backend3 is favored with a weight of 2.
2. **Common Settings:**
- **Quorum:** Each director has a quorum setting of 50%, requiring at least half of the available backends to be healthy or reachable for the director to consider its operations valid.
- **Retries:** Each director is configured to retry three times if a backend selection fails.
### Noteworthy Details:
- **Dynamic Load Shifting:** By altering the backend weights for each hour, the system dynamically shifts the load preference, potentially aligning with expected traffic patterns or backend capabilities at different times.
- **Scalability:** While the code sets up three directors, this pattern can naturally scale beyond three hours or adjusted to include more complex balancing logic if needed.
Overall, this configuration provides a flexible approach to distributing traffic efficiently over a period, adjusting preferences dynamically to enhance backend utilization.
To modify the blueprint to create many directors along a three-hour tour, we can create multiple director declarations. Each director can represent a different time interval or phase in the journey. We'll assume we need three directors for this task, each representing one hour of the journey.
```text
// Director for the first hour of the tour
director hour1_director random {
.quorum = 50%;
.retries = 3;
{ .backend = F_backend1; .weight = 2; }
{ .backend = F_backend2; .weight = 1; }
{ .backend = F_backend3; .weight = 1; }
}
// Director for the second hour of the tour
director hour2_director random {
.quorum = 50%;
.retries = 3;
{ .backend = F_backend1; .weight = 1; }
{ .backend = F_backend2; .weight = 2; }
{ .backend = F_backend3; .weight = 1; }
}
// Director for the third hour of the tour
director hour3_director random {
.quorum = 50%;
.retries = 3;
{ .backend = F_backend1; .weight = 1; }
{ .backend = F_backend2; .weight = 1; }
{ .backend = F_backend3; .weight = 2; }
}
```
In this setup, we keep the quorum and retries the same for each director but adjust the weights associating with each backend for load balancing across different hours of the tour. This approach can be expanded further if more detailed splits or more directors would be necessary.