Messages with nothing in them are considered OtherError, they can not
serve any purpose for normal clients (i.e. dyn update or notifies might
have a use for them).
Also update a test in the cache plugin, so that we explicitaly test for
this case.
* Improve plugin/cache metrics
* Add coredns_cache_prefetch_total metric to track number of prefetches.
* Remove unnecessary Cache.get() call which would incorrectly increment
cache counters.
* Initialize all counters and gauges at zero.
* Allow prefetching of a single request per ttl
The original implementation didn't allow prefetching queries which are
only requested once during the duration of a TTL. The minimum amount of
queries which had to be seen was therefore capped at 2.
This change also implements a real prefetch test. The existing test was
a noop and always passed regardless of any prefetch implementation.
* Fix prefetching for items with a short TTL
The default prefetch threshold (percentage) is 10% of the lifetime of a
cache item. With the previous implementation, this disabled prefetching
for all items with a TTL < 10s (the resulting percentage would be 0, at
which point a cached item is already discarded).
This change uses a time based threshold calculation and ensures that
a prefetch is triggered at a TTL of 1 at the latest.
* Fix wrong duration reporting of cached responses
The logging and metrics plugins (among others) included the duration of
a cache prefetch in the request latency of client request. This change
fixes this wrong reporting and executes the prefetch request in a
goroutine in the background.
* 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
2017-09-14 09:36:06 +01:00
Renamed from middleware/cache/cache_test.go (Browse further)
