loadBalancer

This router middleware needs to receive an options object containing the possible targets for the routed API. This object contains the following properties.

Property	Type	Description	Required
destinations	TrafficDestination[]	A list with possible destinations for the API request.	true
database	DatabaseConfig	Provide a database configuration to the balancer looks for changes in the targets configurations.	false
strategy	round-robin or random or weight	The balancer strategy to be used. The dafilt value is random.	false
healthCheckOptions	HealthCheckOptions	Configure the health checkers.	false

TrafficDestination

Configure a single destination for the balancer. Can contain the following properties:

Property	Type	Description	Required
target	string	A target destination.	true
weight	number	A weight to distribute the load to this target.	true
healthCheck	string	An URL to be used to check the health of this target. It must return a 200 status code, or the balancer will supose that the target is down. If not provided, no health checking will be performed.	false

DatabaseConfig

Configure a database to be used to store configuration for the filter. Is the configuration changes on the database, the filter will be updated. Support the following properties:

Property	Type	Description	Required
key	string	The configuration key to be used in database config table. Defaults to ipFilter:whitelist or ipFilter:blacklist	false
checkInterval	string or number	The interval between database checks for changes in the configurations. You can inform the amount of milisencods, or use a human-interval string. Defaults to '30 seconds'.	false

HealthCheckOptions

Configure how the gateway will perform checks for services health. Support the following properties:

Property	Type	Description	Required
checkInterval	string or number	The interval between healthchecks. You can inform the amount of milisencods, or use a human-interval string. Defaults to '30 seconds'.	false
waitTimeout	string or number	The amount of time to wait for healthcheck requests before fail with a tiemout. You can inform the amount of milisencods, or use a human-interval string. Defaults to '2 seconds'.	false
failCount	number	The number of healthcheck failures before remove the server from the available list. Defaults to 2.	false

Example:

---
name: TestLoadBalancerAPI
version: 1.0.0
path: "/loadBalancer"
proxy:
  target:
    router:
      middleware:
        name: loadBalancer
        options:
          destinations: 
            - target: http://httpbin.org
              weight: 75
              healthCheck: http://httpbin.org/get
            - target: http://httpbin.org/anything
              weight: 25
              healthCheck: http://httpbin.org/anything/get
          database:
            checkInterval: 5 minutes
          strategy: weight
          healthCheckOptions:
            checkInterval: 5 seconds
            failCount: 3
            waitTimeout: 5 seconds
  timeout: 5000

This configuration will route requests to http://httpbin.org and to http://httpbin.org/anything. The first target will receive a bigger load (3 times greater than the second one). It will use a database to be able to change the configuration dynamically and a health check will be performed to avoid traffic redirection to unavailable servers.

Round-robin example:

---
name: TestLoadBalancerAPI
version: 1.0.0
path: "/loadBalancer"
proxy:
  target:
    router:
      middleware:
        name: loadBalancer
        options:
          destinations: 
            - target: http://httpbin.org
              healthCheck: http://httpbin.org/get
            - target: http://httpbin.org/anything
              healthCheck: http://httpbin.org/anything/get
          database:
            checkInterval: 5 minutes
          strategy: round-robin
  timeout: 5000