Create plugin/pkg/transport that holds the transport related functions.
This needed to be a new pkg to prevent cyclic import errors.
This cleans up a bunch of duplicated code in core/dnsserver that also
tried to parse a transport (now all done in transport.Parse).
Signed-off-by: Miek Gieben <miek@miek.nl>
Every plugin needs to deal with EDNS0 and should call Scrub to make a
message fit the client's buffer. Move this functionality into the server
and wrapping the ResponseWriter into a ScrubWriter that handles these
bits for us. Result:
Less code and faster, because multiple chained plugins could all be
calling scrub and SizeAndDo - now there is just one place.
Most tests in file/* and dnssec/* needed adjusting because in those unit
tests you don't see OPT RRs anymore. The DNSSEC signer was also looking
at the returned OPT RR to see if it needed to sign - as those are now
added by the server (and thus later), this needed to change slightly.
Scrub itself still exist (for backward compat reasons), but has been
made a noop. Scrub has been renamed to scrub as it should not be used by
external plugins.
Fixes: #2010
Signed-off-by: Miek Gieben <miek@miek.nl>
* Clean up tests logging
This cleans up the travis logs so you can see the failures better.
Older tests in tests/ would call log.SetOutput(ioutil.Discard) in
a haphazard way. This add log.Discard and put an `init` function in each
package's dir (no way to do this globally). The cleanup in tests/ is
clear.
All plugins also got this init function to have some uniformity and kill
any (future) logging there in the tests as well.
There is a one-off in pkg/healthcheck because that does log.
Signed-off-by: Miek Gieben <miek@miek.nl>
* bring back original log_test.go
Signed-off-by: Miek Gieben <miek@miek.nl>
* suppress logging here as well
Signed-off-by: Miek Gieben <miek@miek.nl>
* plugin/forward: add HealthChecker interface
Make the HealthChecker interface and morph the current DNS health
checker into that interface.
Remove all whole bunch of method on Forward that didn't make sense.
This is done in preparation of adding a DoH client to forward - which
requires a completely different healthcheck implementation (and more,
but lets start here)
Signed-off-by: Miek Gieben <miek@miek.nl>
* Use protocol
Signed-off-by: Miek Gieben <miek@miek.nl>
* Dial doesnt need to be method an Forward either
Signed-off-by: Miek Gieben <miek@miek.nl>
* Address comments
Address various comments on the PR.
Signed-off-by: Miek Gieben <miek@miek.nl>
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.
add a test to see if we copy the rcode correctly. Some minor cleanup in
import ordering and renaming NewUpstream to New as we already are in the
upstream package.
* plugin/forward: erase expired connection by timer
- in previous implementation, the expired connections resided in
cache until new request to the same upstream/protocol came. In
case if the upstream was unhealthy new request may come long time
later or may not come at all. All this time expired connections
held system resources (file descriptors, ephemeral ports). In my
fix the expired connections and related resources are released
by timer
- decreased the complexity of taking connection from cache. The list
of connections is treated as stack (LIFO queue), i.e. the connection
is taken from the end of queue (the most fresh connection) and
returned to the end (as it was implemented before). The remarkable
thing is that all connections in the stack appear to be ordered by
'used' field
- the cleanup() method finds the first good (not expired) connection
in stack with binary search, since all connections are ordered by
'used' field
* fix race conditions
* minor enhancement
* add comments
- connManager() goroutine will stop when Proxy is about to be
garbage collected. This means that no queries are in progress,
and no queries are going to come
* 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
With this change the original truncated message returned by requested
server is returned to the client, instead of returning an empty dummy
message with only the truncation bit set.
- each proxy stores average RTT (round trip time) of last rttCount queries.
For now, I assigned the value 4 to rttCount
- the read timeout is calculated as doubled average RTT, but it cannot
exceed default timeout
- initial avg RTT is set to a half of default timeout, so initial timeout
is equal to default timeout
- the RTT for failed read is considered equal to default timeout, so any
failed read will lead to increasing average RTT (up to default timeout)
- dynamic timeouts will let us react faster on lost UDP packets
- in future, we may develop a low-latency forward policy based on
collected RTT values of proxies
* 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
* plugins: Return error for multiple use of some
Return plugin.ErrOnce when a plugin that doesn't support it, is called
mutliple times.
This now adds it for: cache, dnssec, errors, forward, hosts, nsid.
And changes it slightly in kubernetes, pprof, reload, root.
* more tests
