health checks

Summary

Example object

{
  "timeout_msec": 1000,
  "interval_msec": 60000,
  "interval_jitter_msec": 1000,
  "unhealthy_threshold": 3,
  "healthy_threshold": 3
}

Fields

timeout_msec

TimeoutMsec is the time to wait for a health check response. If the timeout is reached without a response, the health check attempt will be considered a failure. This is a required field and must be greater than 0.

interval_msec

IntervalMsec is the interval between health checks. Note that the first round of health checks will occur during startup before any traffic is routed to a cluster. This means that the no_traffic_interval_msec value will be used as the first interval of health checks.

interval_jitter_msec

IntervalJitterMsec is an optional jitter amount that is added to each interval value calculated by the proxy. If not specified, defaults to 0.

unhealthy_threshold

UnhealthyThreshold is the number of unhealthy health checks required before a host is marked unhealthy. Note that for http health checking if a host responds with 503 this threshold is ignored and the host is considered unhealthy immediately.

healthy_threshold

HealthyThreshold is the number of healthy health checks required before a host is marked healthy. Note that during startup, only a single successful health check is required to mark a host healthy.

reuse_connection

ReuseConnection determines whether to reuse a health check connection between health checks. Default is true.

no_traffic_interval_msec

NoTrafficIntervalMsec is a special health check interval that is used when a cluster has never had traffic routed to it. This lower interval allows cluster information to be kept up to date, without sending a potentially large amount of active health checking traffic or no reason. Once a cluster has been used for traffic routing, The proxy will shift back to using the standard health check interval that is defined. Note that this interval takes precedence over any other. Defaults to 60s.

unhealthy_interval_msec

UnhealthyIntervalMsec is a health check interval that is used for hosts that are marked as unhealthy. As soon as the host is marked as healthy, the proxy will shift back to using the standard health check interval that is defined. This defaults to the same value as IntervalMsec if not specified.

unhealthy_edge_interval_msec

UnhealthyEdgeIntervalMsec is a special health check interval that is used for the first health check right after a host is marked as unhealthy. For subsequent health checks the proxy will shift back to using either "unhealthy interval" if present or the standard health check interval that is defined. Defaults to the same value as UnhealthIntervalMsec if not specified.

healthy_edge_interval_msec

HealthyEdgeIntervalMsec is a special health check interval that is used for the first health check right after a host is marked as healthy. For subsequent health checks the proxy will shift back to using the standard health check interval that is defined. Defaults to the same value as IntervalMsec if not specified

health_checker

Defines the types of health checking to use, options : http_health_check and tcp_health_check. An example of an http health check could be:

{
  ...,
  "health_checker": {
    "http_health_check": {
      "path": "/health"
    }
  }
}