# Health check¶

This extension may be referenced by the qualified name envoy.filters.http.health_check

Note

This extension is intended to be robust against untrusted downstream traffic. It assumes that the upstream is trusted.

Health check configuration overview.

## config.filter.http.health_check.v2.HealthCheck¶

[config.filter.http.health_check.v2.HealthCheck proto]

{
"pass_through_mode": "{...}",
"cache_time": "{...}",
"cluster_min_healthy_percentages": "{...}",
}

pass_through_mode

(BoolValue, REQUIRED) Specifies whether the filter operates in pass through mode or not.

cache_time

(Duration) If operating in pass through mode, the amount of time in milliseconds that the filter should cache the upstream response.

cluster_min_healthy_percentages

(map<string, type.Percent>) If operating in non-pass-through mode, specifies a set of upstream cluster names and the minimum percentage of servers in each of those clusters that must be healthy or degraded in order for the filter to return a 200.

(route.HeaderMatcher) Specifies a set of health check request headers to match on. The health check filter will check a request’s headers against all the specified headers. To specify the health check endpoint, set the :path header to match on.