Motiviation:
The connection handler stream close operation is unconditionally adding a listener object to a future. We may not have to add a listener at all because the future has already been completed.
Modifications:
- If the future is done, directly invoke the logic without creating/adding a new listener.
Result:
No need to create/add listener if the future is already done in close logic.
Motivation:
We need to ensure we never allow to have null values set on headers, otherwise we will see a NPE during encoding them.
Modifications:
Add unit test that shows we correctly handle null values.
Result:
Verify correct implementation.
Motivation:
The current dumping code does not respect the readerIndex and so logs incorrect.
Modifications:
Respect readerIndex of ByteBuf
Result:
Correctly log content of buffer.
Motivation:
If the handlerAdded(...) callback was not called, the checkDeadLock() of the handshakeFuture will produce an IllegalStateException.
This was first reported at https://github.com/impossibl/pgjdbc-ng/issues/168 .
Modifications:
Pass deadlock check if ctx is null
Result:
No more race and so IllegalStateException.
Motivation:
Some glibc/kernel versions will trigger an EPOLLERR event to notify
about failed connect and not an EPOLLOUT. Also EPOLLERR may be triggered
when a connection is broke.
Modification:
React on EPOLLERR like if an EPOLLOUT / EPOLLIN was received, this will work in
all cases as we handle errors in EPOLLOUT / EPOLLIN anyway.
Result:
Correctly detect errors.
Motivation:
gRPC's BufferingHttp2ConnectionEncoder is a generic utility that simplifies client-side applications that want to allow stream creation without worrying about violating the SETTINGS_MAX_CONCURRENT_STREAMS limit. Since it's not gRPC-specific it makes sense to move it into Netty proper.
Modifications:
Adding the BufferingHttp2ConnectionEncoder and it's unit test.
Result:
Netty now supports buffering stream creation.
Motivation:
For advanced use-cases it an be helpful to be able to directly access the SSL_CTX and SSL pointers of the underlying openssl objects. This for example allows to register custom C callbacks.
Modifications:
- Expose the SSL_CTX and SSL pointers
- Cleanup the shutdown code
Result:
It's now possible to obtain the c pointes and set native callbacks.
Motivation:
SpdyOrHttpChooser and Http2OrHttpChooser duplicate fair amount code with each other.
Modification:
- Replace SpdyOrHttpChooser and Http2OrHttpChooser with ApplicationProtocolNegotiationHandler
- Add ApplicationProtocolNames to define the known application-level protocol names
Result:
- Less code duplication
- A user can perform dynamic pipeline configuration that follows ALPN/NPN for any protocols.
Related: #3641 and #3813
Motivation:
When setting up an HTTP/1 or HTTP/2 (or SPDY) pipeline, a user usually
ends up with adding arbitrary set of handlers.
Http2OrHttpChooser and SpdyOrHttpChooser have two abstract methods
(create*Handler()) that expect a user to return a single handler, and
also have add*Handlers() methods that add the handler returned by
create*Handler() to the pipeline as well as the pre-defined set of
handlers.
The problem is, some users (read: I) don't need all of them or the
user wants to add more than one handler. For example, take a look at
io.netty.example.http2.tiles.Http2OrHttpHandler, which works around
this issue by overriding addHttp2Handlers() and making
createHttp2RequestHandler() a no-op.
Modifications:
- Replace add*Handlers() and create*Handler() with configure*()
- Rename getProtocol() to selectProtocol() to make what it does clear
- Provide the default implementation of selectProtocol()
- Remove SelectedProtocol.UNKNOWN and use null instead, because
'UNKNOWN' is not a protocol
- Proper exception handling in the *OrHttpChooser so that the
exception is logged and the connection is closed when failed to
select a protocol
- Make SpdyClient example always use SSL. It was always using SSL
anyway.
- Implement SslHandshakeCompletionEvent.toString() for debuggability
- Remove an orphaned class: JettyNpnSslSession
- Add SslHandler.applicationProtocol() to get the name of the
application protocol
- SSLSession.getProtocol() now returns transport-layer protocol name
only, so that it conforms to its contract.
Result:
- *OrHttpChooser have better API.
- *OrHttpChooser handle protocol selection failure properly.
- SSLSession.getProtocol() now conforms to its contract.
- SpdyClient example works with SpdyServer example out of the box
Motivation:
The logic in the current websocket example is confusing and misleading
Modifications:
Remove occurrences of "http" and "https" and replace them with "ws" and "wss"
Result:
The example code is now coherent and is easier to understand for a new user.
Motivation:
the ByteBuffer[] that we keep in the ThreadLocal are never nulled out which can lead to have ByteBuffer instances sit there forever.
This is even a bigger problem if nioBuffer() of ByteBuffer returns a new ByteBuffer that can not be destroyed by ByteBuffer.release().
Modifications:
Null out ByteBuffer array after processing.
Result:
No more dangling references after done.
Related: #3797
Motivation:
There is a race condition where DnsNameResolver.query() can attempt to
increase the reference count of the DNS response which was released
already by other thread.
Modifications:
- Make DnsCacheEntry a top-level class for clear access control
- Use 'synchronized' to avoid the race condition
- Add DnsCacheEntry.retainedResponse() to make sure that the response
is never released while it is retained
- Make retainedResponse() return null when the response has been
released already, so that DnsNameResolver.query() knows that the
cached entry has been released
Result:
The forementioned race condition has been fixed.
Motivation:
The unit tests should not fail due to using a channel option which is not supported by the underlying kernel.
Modifications:
- Ignore RuntimeExceptions which are thrown by JNI code when setsockopt or getsockopt fails.
Result:
Unit tests pass if socket option is not supported by kernel.
Motiviation:
TCP_NOTSENT_LOWAT is only supported in linux kernel 3.12 or newer. The addition of this socket option prevents older kernels from building.
Modifications:
- Conditionally define TCP_NOTSENT_LOWAT if it is not defined
Result:
Kernels older than 3.12 can still compile the EPOLL module.
Motiviation:
Linux provides the TCP_NOTSENT_LOWAT socket option. This can be used to control how much unsent data is queued in the tcp kernel buffers. This can be important when application level protocols (SPDY, HTTP/2) have their own priority mechanism and don't want data queued in the kernel.
Modifications:
- The epoll module will have an additional socket option TCP_NOTSENT_LOWAT
- There will be JNI methods to control the underlying linux socket option mechanism
Result:
Linux EPOLL module exposes the TCP_NOTSENT_LOWAT socket option.
Motivation:
DatagramUnitcastTest sometimes fails with BindException for an unknown reason.
Modifications:
Retry up to 3 times with a new free port when bind() fails with BindException
Result:
More build stability
Motivation:
SingleThreadEventLoopTest.testScheduleTaskAtFixedRate() fails often due to:
- too little tolerance
- incorrect assertion (it compares only with the previous timestamp)
Modifications:
- Increase the timestamp difference tolerance from 10ms to 20ms
- Improve the timestamp assertion so that the comparison is performed against the first recorded timestamp
- Misc: Fix broken Javadoc tag
Result:
More build stability
Motivation:
SocketSslEchoTest.testSslEcho() has a race condition where a renegotiation future can be done before:
assertThat(renegoFuture.isDone(), is(false));
Modifications:
Remove the offending assertion.
Result:
More build stability
Motivation:
the JNI function ThrowNew won't release any allocated memory.
The method exceptionMessage is allocating a new string concatenating 2 constant strings
What is creating a small leak in case of these exceptions are happening.
Modifications:
Added new methods that will use exceptionMessage and free resources accordingly.
I am also removing the inline definition on these methods as they could be reused by
other added modules (e.g. libaio which should be coming soon)
Result:
No more leaks in case of failures.
Motivation:
When a faulty never-ending test keeps producing a lot of garbage doing
nothing but generating CPU load, our CI fails to detect the stalled
build, because it determines the 'inactivity time' from console
activity and GC keeps producing console output.
Modifications:
Remove the -verbose:gc flag from pom.xml
Result:
Stalled builds are terminated by our CI server.
Motivation:
PoolThreadCache did only cache allocations if the allocation and deallocation Thread were the same. This is not optimal as often people write from differen thread then the actual EventLoop thread.
Modification:
- Add MpscArrayQueue which was forked from jctools and lightly modified.
- Use MpscArrayQueue for caches and always add buffer back to the cache that belongs to the allocation thread.
Result:
ThreadPoolCache is now also usable and so gives performance improvements when allocation and deallocation thread are different.
Performance when using same thread for allocation and deallocation is noticable worse then before.
Motivation:
Calling System.nanoTime() for each channelRead(...) is very expensive. See [#3808] for more detailed description.
Also we always do extra work for each write and read even if read or write idle states should not be handled.
Modifications:
- Move System.nanoTime() call to channelReadComplete(...).
- Reuse ChannelFutureListener for writes
- Only add ChannelFutureListener to writes if write and all idle states should be handled.
- Only call System.nanoTime() for reads if idle state events for read and all states should be handled.
Result:
Less overhead when using the IdleStateHandler.
Motivation:
We called TrustManagerFactory.init(...) even when the trustCertChainFile is null. This could lead to exceptions during the handshake.
Modifications:
Correctly only call TurstManagerFactory.init() if trustCertcChainFail is not null.
Result:
Correct behavior.
Motivation:
Due a bug we not correctly handled connection refused errors and so failed the connect promise with the wrong exception.
Beside this we some times even triggered fireChannelActive() which is not correct.
Modifications:
- Add testcase
- correctly detect connect errors
Result:
Correct and consistent handling.
Motivation:
Currently we hold a lock on the PoolArena when we allocate / free PoolSubpages, which is wasteful as this also affects "normal" allocations. The same is true vice-verse.
Modifications:
Ensure we synchronize on the head of the PoolSubPages pool. This is done per size and so it is possible to concurrently allocate / deallocate PoolSubPages with different sizes, and also normal allocations.
Result:
Less condition and so faster allocation/deallocation.
Before this commit:
xxx:~/wrk $ ./wrk -H 'Connection: keep-alive' -d 120 -c 256 -t 16 -s scripts/pipeline-many.lua http://xxx:8080/plaintext
Running 2m test @ http://xxx:8080/plaintext
16 threads and 256 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 17.61ms 29.52ms 689.73ms 97.27%
Req/Sec 278.93k 41.97k 351.04k 84.83%
530527460 requests in 2.00m, 71.64GB read
Requests/sec: 4422226.13
Transfer/sec: 611.52MB
After this commit:
xxx:~/wrk $ ./wrk -H 'Connection: keep-alive' -d 120 -c 256 -t 16 -s scripts/pipeline-many.lua http://xxx:8080/plaintext
Running 2m test @ http://xxx:8080/plaintext
16 threads and 256 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 15.85ms 24.50ms 681.61ms 97.42%
Req/Sec 287.14k 38.39k 360.33k 85.88%
547902773 requests in 2.00m, 73.99GB read
Requests/sec: 4567066.11
Transfer/sec: 631.55MB
This is reproducable every time.
Motiviation:
At the moment we sometimes hold the lock on the PoolArena during destroy a PoolChunk. This is not needed.
Modification:
- Ensure we not hold the lock during destroy a PoolChunk
- Move all synchronized usage in PoolArena
- Cleanup
Result:
Less condition.
Motiviation:
The OpenSSL engine uses SSLHandshakeException in the event of failures that occur during the handshake process. The alpn-boot project's getSSLException will also map the no_application_protocol to a SSLHandshakeException exception. We should be consistent and use SSLHandshakeException for handshake failure events.
Modifications:
-Update JdkAlpnSslEngine to propagate an SSLHandshakeException in the event of a failure.
Result:
Consistent usage of SSLHandshakeException during a handshake failure event.
Motivation:
Found a bug in that netty would generate a 20 byte body when returing a response
to an HTTP HEAD. the 20 bytes seems to be related to the compression footer.
RFC2616, section 9.4 states that responses to an HTTP HEAD MUST not return a message
body in the response.
Netty's own client implementation expected an empty response. The extra bytes lead to a
2nd response with an error decoder result:
java.lang.IllegalArgumentException: invalid version format: 14
Modifications:
Track the HTTP request method. When processing the response we determine if the response
is passthru unnchanged. This decision now takes into account the request method and passthru
responses related to HTTP HEAD requests.
Result:
Netty's http client works and better RFC conformance.
Motivation:
Allow writing with void promise if IdleStateHandler is configured in the pipeline for read timeout events.
Modifications:
Better performance.
Result:
No more ChannelFutureListeners are created if IdleStateHandler is only configured for read timeouts allowing for writing to the channel with void promise.
Motivation:
[#3808] introduced some improvements to reduce the calls to System.nanoTime() but missed one possible optimization.
Modifications:
Only call System.nanoTime() if no reading patch is in process.
Result:
Less System.nanoTime() calls.
Motivation:
There are no Netty SCTP examples on multi-homing.
Modifications:
- Added new example classes based on echo client/server example
Result:
Better documentation
Motivation:
Discussion is in https://github.com/jetty-project/jetty-alpn/issues/8. The new API allows protocol negotiation to properly throw SSLHandshakeException.
Modifications:
Updated the parent pom.xml with the new version.
Result:
Upgraded alpn-api now allows throwing SSLHandshakeException.
Motivation:
There is currently no good way to configure the initial SETTINGS frame. The individual settings can be configured on the various components, but doing this bypasses the proper setting update logic in the encoder.
Modifications:
Updated Http2ConnectionHandler to optionally take initial settings in the constructor. If not provided, it will default to current behavior.
Result:
Easy manual configuration of initial settings.
Motivation:
When trying to write more then Integer.MAX_VALUE / SSIZE_MAX via writev(...) the OS may return EINVAL depending on the kernel or the actual OS (bsd / osx always return EINVAL). This will trigger an IOException.
Modifications:
Never try to write more then Integer.MAX_VALUE / SSIZE_MAX when using writev.
Result:
No more IOException when write more data then Integer.MAX_VALUE / SSIZE_MAX via writev.
Motivation:
We mitigate callouts to System.nanoTime() in SingleThreadEventExecutor
as it is 'relatively expensive'. On a modern system, tak translates to
about 20ns per call. With channelReadComplete() we can side-step this in
channelRead().
Modifications:
Introduce a boolean flag, which indicates that a read batch is currently
on-going, which acts as a flush guard for lastReadTime. Update
lastReadTime in channelReadComplete() just before setting the flag to
false. We set the flag to true in channelRead().
The periodic task examines the flag, and if it observes it to be true,
it will reschedule the task for the full duration. If it observes as
false, it will read lastReadTime and adjust the delay accordingly.
Result:
ReadTimeoutHandler calls System.nanoTime() only once per read batch.
Motivation:
The PooledByteBufAllocator is more or less a black-box atm. We need to expose some metrics to allow the user to get a better idea how to tune it.
Modifications:
- Expose different metrics via PooledByteBufAllocator
- Add *Metrics interfaces
Result:
It is now easy to gather metrics and detail about the PooledByteBufAllocator and so get a better understanding about resource-usage etc.
Motivation:
The Http2OutboundFrameLogger logs all PING frames as not acks.
Modifications:
Changed the logger to correctly log PING acks.
Result:
PING acks are logged correctly.
Motivation:
At the moment when calling slice(...) or duplicate(...) on a Pooled*ByteBuf a new SlicedByteBuf or DuplicatedByteBuf. This can create a lot of GC.
Modifications:
Add PooledSlicedByteBuf and PooledDuplicatedByteBuf which will be used when a PooledByteBuf is used.
Result:
Less GC.
Motivation:
From the javadocs of ByteBuf.duplicate() it is not clear if the reader and writer marks will be duplicated.
Modifications:
Add sentence to clarify that marks will not be duplicated.
Result:
Clear semantics.
Motivation:
When allocate a PooledByteBuf we need to ensure to also reset the markers for the readerIndex and writerIndex.
Modifications:
- Correct reset the markers
- Add test-case for it
Result:
Correctly reset markers.
Motiviation:
When tried to allocate tiny and small sized and failed to serve these out of the PoolSubPage we exit the synchronization
block just to enter it again when call allocateNormal(...).
Modification:
Not exit the synchronized block until allocateNormal(...) is done.
Result:
Better performance.
Motivation:
Adding an example that showcases Netty’s HTTP/2 codec and that is
slightly more complex than the existing hello-world example. It is
based on the Gopher tiles example available here:
https://http2.golang.org/gophertiles?latency=0
Modifications:
Moved current http2 example to http2/helloworld.
Added http2 tiles example under http2/tiles.
Result:
A Netty tiles example is available.
