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 upstreams
object.
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 probingcount_up
: how many times a probe should be successful before the URL can be considered as workingcount_down
: how many times a probe should fail before the URL can be considered as non workingmethod
: which method, among GET/POST/PUT/PATCH needs to be used by the probetimeout
: how long should a probe wait for a reply before it considers the URL as non responsive and therefore call it a failurestatus
: the expected status codeinterval
: how frequently should the probe run
Notes
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.