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plugin/pkg/up: make default intervals shorter (#3651)

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* plugin/pkg/up: make default intervals shorter

I think 15 min is too high, make this lower to react faster.

Signed-off-by: Miek Gieben <miek@miek.nl>

* Update README

Signed-off-by: Miek Gieben <miek@miek.nl>
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Miek Gieben 2020-02-06 19:28:53 +01:00 • committed by GitHub
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2 changed files with 10 additions and 10 deletions
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16
plugin/forward/README.md
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@ -9,14 +9,14 @@
The *forward* plugin re-uses already opened sockets to the upstreams. It supports UDP, TCP and The *forward* plugin re-uses already opened sockets to the upstreams. It supports UDP, TCP and
DNS-over-TLS and uses in band health checking. DNS-over-TLS and uses in band health checking.
When it detects an error a health check is performed. This checks runs in a loop, When it detects an error a health check is performed. This checks runs in a loop, starting with
starting with a *0.5s* interval and exponentially backing off with randomized intervals a *0.5s* interval and exponentially backing off with randomized intervals up to *15s* for as long
up to *60s* for as long as the upstream reports unhealthy. The exponential backoff as the upstream reports unhealthy. The exponential backoff will reset to *0.5s* after 2 minutes.
will reset to *0.5s* after 15 minutes. Once healthy we stop health checking (until the next Once healthy we stop health checking (until the next error). The health checks use a recursive
error). The health checks use a recursive DNS query (`. IN NS`) to get upstream health. Any response DNS query (`. IN NS`) to get upstream health. Any response that is not a network error (REFUSED,
that is not a network error (REFUSED, NOTIMPL, SERVFAIL, etc) is taken as a healthy upstream. The NOTIMPL, SERVFAIL, etc) is taken as a healthy upstream. The health check uses the same protocol as
health check uses the same protocol as specified in **TO**. If `max_fails` is set to 0, no checking specified in **TO**. If `max_fails` is set to 0, no checking is performed and upstreams will always
is performed and upstreams will always be considered healthy. be considered healthy.
When *all* upstreams are down it assumes health checking as a mechanism has failed and will try to When *all* upstreams are down it assumes health checking as a mechanism has failed and will try to
connect to a random upstream (which may or may not work). connect to a random upstream (which may or may not work).

4
plugin/pkg/up/up.go
View file

@ -79,8 +79,8 @@ func (p *Probe) Start(interval time.Duration) {
InitialInterval: interval, InitialInterval: interval,
RandomizationFactor: backoff.DefaultRandomizationFactor, RandomizationFactor: backoff.DefaultRandomizationFactor,
Multiplier: backoff.DefaultMultiplier, Multiplier: backoff.DefaultMultiplier,
MaxInterval: backoff.DefaultMaxInterval, MaxInterval: 15 * time.Second,
MaxElapsedTime: backoff.DefaultMaxElapsedTime, MaxElapsedTime: 2 * time.Minute,
Stop: backoff.Stop, Stop: backoff.Stop,
Clock: backoff.SystemClock, Clock: backoff.SystemClock,
} }