48059a6c3e
* plugin/health: add 'overloaded metrics' Query our on health endpoint and record (and export as a metric) the time it takes. The Get has a 5s timeout, that, when reached, will set the metric duration to 5s. The actually call "I'm I overloaded" is left to an external entity. * README * golint and govet * and the tests |
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|---|---|---|
| .. | ||
| health.go | ||
| health_test.go | ||
| healther.go | ||
| overloaded.go | ||
| README.md | ||
| setup.go | ||
| setup_test.go | ||
health
Name
health - enables a health check endpoint.
Description
By enabling health any plugin that implements it will be queried for it's health. The combined health is exported, by default, on port 8080/health .
Syntax
health [ADDRESS]
Optionally takes an address; the default is :8080. The health path is fixed to /health. The
health endpoint returns a 200 response code and the word "OK" when CoreDNS is healthy. It returns
a 503. health periodically (1s) polls plugin that exports health information. If any of the
plugin signals that it is unhealthy, the server will go unhealthy too. Each plugin that
supports health checks has a section "Health" in their README.
Plugins
Any plugin that implements the Healther interface will be used to report health.
Metrics
If monitoring is enabled (via the prometheus directive) then the following metric is exported:
coredns_health_request_duration_seconds{}- duration to process a /health query. As this should be a local operation it should be fast. A (large) increases in this duration indicates the CoreDNS process is having trouble keeping up.
Examples
Run another health endpoint on http://localhost:8091.
. {
health localhost:8091
}