Allow plugins to dump messages in text pcap to the log. The forward
plugin does this when a reply does not much the query.
If the debug plugin isn't loaded Hexdump and Hexdumpf are noop.
Signed-off-by: Miek Gieben <miek@miek.nl>
After several experiments at SoundCloud we found that the current
minimum read timeout of 10ms is too low. A single request against a
slow/unavailable authoritative server can cause all TCP connections to
get closed. We record a 50th percentile forward/proxy latency of <5ms,
and a 99th percentile latency of 60ms. Using a minimum timeout of 200ms
seems to be a fair trade-off between avoiding unnecessary high
connection churn and reacting to upstream failures in a timely manner.
This change also renames hcDuration to hcInterval to reflect its usage,
and removes the duplicated timeout constant to make code comprehension
easier.
* Remove Compress by default
Set Compress = true in Scrub only when the message doesn not fit the
advertized buffer. Doing compression is expensive, so try to avoid it.
Master vs this branch
pkg: github.com/coredns/coredns/plugin/cache
BenchmarkCacheResponse-2 50000 24774 ns/op
pkg: github.com/coredns/coredns/plugin/cache
BenchmarkCacheResponse-2 100000 21960 ns/op
* and make it compile
Rework the TestProxyClose - close the proxy in the *same* goroutine
as where we started it. Close channels as long as we don't get dataraces
(this may need another fix).
Move the Dial goroutine out of the connManager - this simplifies things
*and* makes another goroutine go away and removes the need for connErr
channels - can now just be dns.Conn.
Also:
Revert "plugin/forward: gracefull stop (#1701)"
This reverts commit 135377bf77.
Revert "rework TestProxyClose (#1735)"
This reverts commit 9e8893a0b5.
* plugin/forward: gracefull stop
- stop connection manager only when no queries in progress
* minor improvement
* prevent healthcheck on stopped proxy
* revert closing channels
* use standard context
* global: move to context
Move from golang.org/x/net/context to std lib's context.
Change done with:
for i in $(grep -l '/context' **/*.go); do sed -e 's|golang.org/x/net/context|context|' -i $i; echo $i; done
for i in **/*.go; do goimports -w $i; done
* drop from dns.pb.go as well
* plugin/forward: TCP conns can be closed
Only when we read and get a io.EOF we know the conn is closed (for TCP).
If this is the case Dial (again) and retry. Note that this new
connection can also be closed by the upstream, we may want to add a
DialForceNew or something to get a new TCP connection..
Simular to #1624, *but* this is by (TCP) design. We also don't have to
wait for a timeout which makes it easier to reason about.
* Move to forward.go
* doesnt need changing
* plugin/{cache,forward,proxy}: don't allow responses that are bogus
Responses that are not matching what we've been querying for should be
dropped. They are converted into FormErrs by forward and proxy; as a 2nd
backstop cache will also not cache these.
* plug
* add explicit test
* plugin/forward: on demand healtchecking
Only start doing health checks when we encouner an error (any error).
This uses the new pluing/pkg/up package to abstract away the actual
checking. This reduces the LOC quite a bit; does need more testing, unit
testing and tcpdumping a bit.
* fix tests
* Fix readme
* Use pkg/up for healthchecks
* remove unused channel
* more cleanups
* update readme
* * Again do go generate and go build; still referencing the wrong forward
repo? Anyway fixed.
* Use pkg/up for doing the healtchecks to cut back on unwanted queries
* Change up.Func to return an error instead of a boolean.
* Drop the string target argument as it doesn't make sense.
* Add healthcheck test on failing to get an upstream answer.
TODO(miek): double check Forward and Lookup and how they interact with
HC, and if we correctly call close() on those
* actual test
* Tests here
* more tests
* try getting rid of host
* Get rid of the host indirection
* Finish removing hosts
* moar testing
* import fmt
* field is not used
* docs
* move some stuff
* bring back health_check
* maxfails=0 test
* git and merging, bah
* review
* plugin/forward: add it
This moves coredns/forward into CoreDNS. Fixes as a few bugs, adds a
policy option and more tests to the plugin.
Update the documentation, test IPv6 address and add persistent tests.
* Always use random policy when spraying
* include scrub fix here as well
* use correct var name
* Code review
* go vet
* Move logging to metrcs
* Small readme updates
* Fix readme
