* perf(loadbalance): fast-path zero-allocation roundRobin for homogeneous record sets
Signed-off-by: Manuel Rüger <manuel@rueg.eu>
* plugin/loadbalance: copy before shuffling in the fast path
The fast path shuffled the caller's slice in place, which is not safe.
roundRobin must not modify its input: a backend may hand back a slice it
owns rather than one built for the response. plugin/file does exactly that
- Lookup returns elem.Type(qtype), which is the zone tree's own []dns.RR -
so an in-place shuffle reorders the zone itself, visible to every other
query and racing with the ones running concurrently.
Copy the records into a fresh slice and shuffle that instead. This is still
a single allocation rather than the four slices the partitioning path builds,
so most of the gain is kept:
name old time/op new time/op delta
RoundRobin 353 ns 244 ns -31%
name old alloc/op new alloc/op delta
RoundRobin 118 B 54 B -54%
name old allocs/op new allocs/op delta
RoundRobin 5 4 -20%
Also reorder the type check so a response led by a CNAME is rejected on the
first record instead of scanning the whole answer section first.
TestRoundRobinDoesNotMutateInput pins the contract; it fails against the
in-place version.
Signed-off-by: Manuel Rüger <manuel@rueg.eu>
---------
Signed-off-by: Manuel Rüger <manuel@rueg.eu>
Replace naked returns with explicit return values to satisfy nakedret
linter and improve readability.
Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>
The loadbalancer plugin reorders records. It was doing this for zone
transfers - if you had a CNAME in the zone then your transfer would
be broken because it would get put before the SOA record.
* 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
Add a full test server impl in this new package + tests. Move
dnsrecorder into this package as well and finish up the commented out
tests that were left in the old dnsrecorder package.
Update all callers and tests.
* Rename middleware to plugin
first pass; mostly used 'sed', few spots where I manually changed
text.
This still builds a coredns binary.
* fmt error
* Rename AddMiddleware to AddPlugin
* Readd AddMiddleware to remain backwards compat
