* 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>
Enable intrange linter to enforce modern Go range syntax over
traditional for loops, by converting:
for i := 0; i < n; i++
to:
for i := range n
Adding type conversions where needed for compatibility
with existing uint64 parameters.
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.
* update docs
* plugins: use plugin specific logging
Hooking up pkg/log also changed NewWithPlugin to just take a string
instead of a plugin.Handler as that is more flexible and for instance
the Root "plugin" doesn't implement it fully.
Same logging from the reload plugin:
.:1043
2018/04/22 08:56:37 [INFO] CoreDNS-1.1.1
2018/04/22 08:56:37 [INFO] linux/amd64, go1.10.1,
CoreDNS-1.1.1
linux/amd64, go1.10.1,
2018/04/22 08:56:37 [INFO] plugin/reload: Running configuration MD5 = ec4c9c55cd19759ea1c46b8c45742b06
2018/04/22 08:56:54 [INFO] Reloading
2018/04/22 08:56:54 [INFO] plugin/reload: Running configuration MD5 = 9e2bfdd85bdc9cceb740ba9c80f34c1a
2018/04/22 08:56:54 [INFO] Reloading complete
* update docs
* better doc
* Update all plugins to use plugin/pkg/log
I wish this could have been done with sed. Alas manually changed all
callers to use the new plugin/pkg/log package.
* Error -> Info
* Add docs to debug plugin as well
* 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
