Performance benchmarks can be found below. Obviously, a 8 KiB
request/response is tailored to showcase this improvement as this is
where codec buffer reuse shines, but I've run other benchmarks too (like
1-byte requests and responses) and there's no discernable impact on
performance.
We do not allow reuse of buffers when stat handlers or binlogs are
turned on. This is because those two may need access to the data and
payload even after the data has been written to the wire. In such cases,
we never return the data back to the pool.
A buffer reuse threshold of 1 KiB was determined after several
experiments. There's diminished returns when buffer reuse is enabled for
smaller messages (actually, a negative impact).
unary-networkMode_none-bufConn_false-keepalive_false-benchTime_40s-trace_false-latency_0s-kbps_0-MTU_0-maxConcurrentCalls_6-reqSize_8192B-respSize_8192B-compressor_off-channelz_false-preloader_false
Title Before After Percentage
TotalOps 839638 906223 7.93%
SendOps 0 0 NaN%
RecvOps 0 0 NaN%
Bytes/op 103788.29 80592.47 -22.35%
Allocs/op 183.33 189.30 3.27%
ReqT/op 1375662899.20 1484755763.20 7.93%
RespT/op 1375662899.20 1484755763.20 7.93%
50th-Lat 238.746µs 225.019µs -5.75%
90th-Lat 514.253µs 456.439µs -11.24%
99th-Lat 711.083µs 702.466µs -1.21%
Avg-Lat 285.45µs 264.456µs -7.35%
Previously this would fall into returning the same "s.header.Copy(), nil"
condition at the end of the function, returning an empty MD. After a recent
change it would instead check headerValid, which is always false on servers,
and return nil and an error. Callers were ignoring this error so no behavior
change was seen, but there is no need to check s.headers here.
Before this fix, stream is removed from activeStreams in finishStream,
which happens when the service handler returns status, without waiting
for the status to be sent by loopyWriter. If GracefulStop() is called in
between, it will close the connection (because activeStreams is empty),
which causes the RPC to fail with "transport is closing". This change
moves the activeStreams cleanup into loopyWriter, after sending status
on wire.
* Expose a method from the internal package to get to the raw
StatusProto wrapped by the status error, and use it from
http2Server.WriteStatus().
* Add a helper method in internal/testutils to compare two status errors
and update test code to use that instead of reflect.DeepEqual()
* When a RST_STREAM is received by the server transport, a cleanupStream
item is placed into controlbuf no matter what.
* Updates comments.
* Replaces getCleanupStream with inline struct initialization.
feihu-stripe
Doug Fawley
Lidi Zheng
Zach Reyes
idiamond-stripe
Anthonin Bonnefoy
Easwar Swaminathan
Uddeshya Singh
Yury Frolov
James Protzman
Tzu-Chiao Yeh
Garrett Gutierrez
Menghan Li
Bryan Boreham
Matthew Dolan
Adhityaa Chandrasekar
Adhityaa Chandrasekar
Mo Zhonghua
Can Guler
David Zbarsky