Bloodhound – Backends – Load balancing
Bloodhound has a simple load balancing capability we are going to discuss now. Before moving forward, make sure you have read the basic configuration guide.
The backends in the
backends.yml can alternatively be expressed as follows:
- prefix: '[^/]*/upstreams' upstreams: urls: - 'https://server-1/endpoint' - 'https://server-2/endpoint' probe: count_up: 2 count_down: 2 method: GET timeout: 2 seconds path: '' status: 200 interval: 10 seconds flow_id: default
In this configuration,
upstream is replaced by the
urls: a list of URLs that will be used as upstreams
probe: the system will probe each URL periodically to make sure they are available. The probe is optional and, if omitted, Bloodhound will always considers URLs as functional.
path: an extra path segment to be appeneded to the URL when probing
count_up: how many times a probe should be successful before the URL can be considered as working
count_down: how many times a probe should fail before the URL can be considered as non working
method: which method, among GET/POST/PUT/PATCH needs to be used by the probe
timeout: how long should a probe wait for a reply before it considers the URL as non responsive and therefore call it a failure
status: the expected status code
interval: how frequently should the probe run
The system will look for a
probe thread pool in the
implementers.yml file. If no
probe thread pool is defined, default will be used. Please refer to the fine tuning guide to learn more.