coredns: work on tcp requests concurrently #503
Merged
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Right now for a single network all requests where processed serial and
with tcp a caller is able to block us for a long time if it just opens
the connection but sends very little or no data. To avoid this always
spawn a new task if we accept a new tcp connection.
We could do the same for udp however my testing with contrib/perf/run.sh
has shown that it slows things down as the overhead of spawning a task
is greater than the few quick simple map lookups so we only spawn where
needed. We still have to spawn when forwarding external requests as this
can take a long time.
Fixes #500