Motivation:
bbc34d0eda introduced correct handling of "in process" setup of streams but there is some room for improvements. Often the writeHeaders(...) is completed directly which means there is not need to create the extra listener object.
Modifications:
- Only create the listener if we really need too.
Result:
Less GC
Motivation:
In https://github.com/netty/netty/issues/8692, `Http2FrameCodec` was
updated to keep track of all "being initialized" streams, allocating
memory before initialization begins, and releasing memory after
initialization completes successfully.
In some instances where stream initialization fails (e.g. because this
connection has received a GOAWAY frame), this memory is never released.
Modifications:
This change updates the `Http2FrameCodec` to use a separate promise
for monitoring the success of sending HTTP2 headers. When sending of
headers fails, we now make sure to release memory allocated for stream
initialization.
Result:
After this change, failures in writing HTTP2 Headers (e.g. because this
connection has received a GOAWAY frame) will no longer leak memory.
Motivation:
Http2MultiplexCodec extends Http2FrameCodec extends Http2ConnectionHandler. It appears Http2MultiplexCodec overrode the channelWritabilityChanged method, which prevented the flow controller from becoming active. In the case the parent channel becomes unwritable, and then later becomes writable, it needs to indicate that the child channels can still write data. This is slightly confusing, because the child channels may still themselves be unwritable, but should still drain their data to the parent channel.
Modification:
Still propagate writability changes to the HTTP/2 flow controller
Result:
Fixes https://github.com/netty/netty/issues/9636
Motivation:
Native image compilation is failing without extra flags:
```
Warning: Aborting stand-alone image build. No instances of io.netty.buffer.UnpooledHeapByteBuf are allowed in the image heap as this class should be initialized at image runtime. Object has been initialized by the io.netty.handler.codec.http2.Http2ConnectionHandler class initializer with a trace:
at io.netty.buffer.Unpooled.wrappedBuffer(Unpooled.java:157)
at io.netty.handler.codec.http2.Http2ConnectionHandler.<clinit>(Http2ConnectionHandler.java:74)
. To fix the issue mark io.netty.buffer.UnpooledHeapByteBuf for build-time initialization with --initialize-at-build-time=io.netty.buffer.UnpooledHeapByteBuf or use the the information from the trace to find the culprit and --initialize-at-run-time=<culprit> to prevent its instantiation.
Detailed message:
Trace: object io.netty.buffer.ReadOnlyByteBuf
object io.netty.buffer.UnreleasableByteBuf
method io.netty.handler.codec.http2.Http2ConnectionHandler.access$500()
Call path from entry point to io.netty.handler.codec.http2.Http2ConnectionHandler.access$500():
at io.netty.handler.codec.http2.Http2ConnectionHandler.access$500(Http2ConnectionHandler.java:66)
at io.netty.handler.codec.http2.Http2ConnectionHandler$PrefaceDecoder.readClientPrefaceString(Http2ConnectionHandler.java:299)
at io.netty.handler.codec.http2.Http2ConnectionHandler$PrefaceDecoder.decode(Http2ConnectionHandler.java:239)
at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:438)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:505)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:444)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:283)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
at io.netty.channel.AbstractChannelHandlerContext.access$600(AbstractChannelHandlerContext.java:56)
at io.netty.channel.AbstractChannelHandlerContext$7.run(AbstractChannelHandlerContext.java:365)
at com.oracle.svm.core.jdk.RuntimeSupport.executeHooks(RuntimeSupport.java:144)
at com.oracle.svm.core.jdk.RuntimeSupport.executeStartupHooks(RuntimeSupport.java:89)
at com.oracle.svm.core.JavaMainWrapper.runCore(JavaMainWrapper.java:143)
at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:186)
at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0)
```
Modification:
Add `io.netty.handler.codec.http2.Http2ConnectionHandler` for runtime compilation, as the buffer library's `io.netty.buffer.UnpooledHeapByteBuf` is also marked for runtime.
Result:
Native image compilation works again.
Motivation:
`DefaultHttp2UnknownFrame#equals` may produce NPE due to
incorrect comparison of `stream` field.
Modification:
- Fix the `stream` field compare.
- Cleanup usage of class fields: use direct access instead of getters
(because the class is final).
Result:
No NPE in `equals` method.
Motivation:
Classes `AbstractHttp2StreamChannel.Http2StreamChannelConfig`
and `DnsNameResolver.AddressedEnvelopeAdapter` may be static:
it doesn't reference its enclosing instance.
Modification:
Add `static` modifier.
Result:
Prevents a possible memory leak and uses less memory per class instance.
Motivation:
At the moment we use Unpooled.buffer(...) in InboundHttp2ToHttpAdapter when we need to do a copy of the message. We should better use the configured ByteBufAllocator for the Channel
Modifications:
Change internal interface to also take the ByteBufAllocator as argument and use it when we need to allocate a ByteBuf.
Result:
Use the "correct" ByteBufAllocator in InboundHttp2ToHttpAdapter in all cases
Motivation:
At the moment we set release to false before we call writeData(...). This could let to the sitatuation that we will miss to release the message if writeData(...) throws. We should set release to false after we called writeData(...) to ensure the ownership of the buffer is correctly transferred.
Modifications:
- Set release to false after writeData(...) was successfully called only
Result:
No possibility for a buffer leak
Motivation:
We did miss to take Http2FrameCodecBuilder.isValidateHeaders() into account when a Http2FrameWriter was set on the builder and always assumed validation should be enabled.
Modifications:
Remove hardcode value and use configured value
Result:
Http2FrameCodecBuilder.isValidateHeaders() is respected in all cases
Motivation:
Error: Class that is marked for delaying initialization to run time got initialized during image building: io.netty.handler.codec.http2.Http2CodecUtil. Try marking this class for build-time initialization with --initialize-at-build-time=io.netty.handler.codec.http2.Http2CodecUtil
Error: Use -H:+ReportExceptionStackTraces to print stacktrace of underlying exception
Error: Image build request failed with exit status 1
Modification:
After debugging, it seems the culprit is io.netty.handler.codec.http2.Http2ClientUpgradeCodec, which also needs runtime initialisation.
Result:
Fixes #micronaut-projects/micronaut-grpc#8
Motivation:
Right now you can cancel the Future returned by
`Http2StreamChannelBootstrap.open()` and that will race with the
registration of the stream channel with the event loop, potentially
culminating in an `IllegalStateException` and potential resource leak.
Modification:
Ensure that the returned promise is uncancellable.
Result:
Should no longer see `IllegalStateException`s.
Motivation:
In the release (4.1.37) we introduced Http2MultiplexHandler as a
replacement of Http2MultiplexCodec. This did split the frame parsing from
the multiplexing to allow a more flexible way to handle frames and to make
the code cleaner. Unfortunally we did miss to special handle this in
Http2ClientUpgradeCodec and so did not correctly add Http2MultiplexHandler
to the pipeline before calling Http2FrameCodec.onHttpClientUpgrade(...).
This did lead to the situation that we did not correctly receive the event
on the Http2MultiplexHandler and so did not correctly created the
Http2StreamChannel for the upgrade stream. Because of this we ended up
with an NPE if a frame was dispatched to the upgrade stream later on.
Modifications:
- Correctly add Http2MultiplexHandler to the pipeline before calling Http2FrameCodec.onHttpClientUpgrade(...)
Result:
Fixes#9495.
Motivation:
Some of the links in javadoc point to the obsolete drafts of HTTP/2
specifications. We should point them to the latest RFC 7540 or 7541.
Modifications:
Update links from `draft-ietf-httpbis-*` to the `rfc7540` and `rfc7541`.
Result:
Correct links in javadoc.
Motivation:
We should better update the flow-controller on Channel.read() to reduce overhead and memory overhead.
See https://github.com/netty/netty/pull/9390#issuecomment-513008269
Modifications:
Move updateLocalWindowIfNeeded() to doBeginRead()
Result:
Reduce memory overhead
Motivation:
As we decorate the Http2FrameListener under the covers we should ensure the user can still access the original Http2FrameListener.
Modifications:
- Unwrap the Http2FrameListener in frameListener()
- Add unit test
Result:
Less suprises for users.
Motivation:
We recently introduced Http2ControlFrameLimitEncoderTest which did not correctly notify the goAway promises and so leaked buffers.
Modifications:
Correctly notify all promises and so release the debug data.
Result:
Fixes leak in HTTP2 test
Motivation:
It is possible for a remote peer to flood the server / client with empty DATA frames (without end_of_stream flag) set and so cause high CPU usage without the possibility to ever hit a limit. We need to guard against this.
See CVE-2019-9518
Modifications:
- Add a new config option to AbstractHttp2ConnectionBuilder and sub-classes which allows to set the max number of consecutive empty DATA frames (without end_of_stream flag). After this limit is hit we will close the connection. A limit of 10 is used by default.
- Add unit tests
Result:
Guards against CVE-2019-9518
Motivation:
Due how http2 spec is defined it is possible by a remote peer to flood us with frames that will trigger control frames as response, the problem here is that the remote peer can also just stop reading these (while still produce more of these) and so may drive us to the pointer where we either run out of memory or burn all CPU. To protect against this we need to implement some kind of limit that will tear down connections that cause the above mentioned situation.
See CVE-2019-9512 / CVE-2019-9514 / CVE-2019-9515
Modifications:
- Add Http2ControlFrameLimitEncoder which limits the number of queued control frames that were caused because of the remote peer.
- Allow to insert ths Http2ControlFrameLimitEncoder by setting AbstractHttp2ConnectionBuilder.encoderEnforceMaxQueuedControlFrames(...) to a number higher then 0. The default is 10000 which provides some protection by default but will hopefully not cause too many false-positives.
- Add unit tests
Result:
Protect against DDOS due control frames. Fixes CVE-2019-9512 / CVE-2019-9514 / CVE-2019-9515 .
Motivation:
We should delay the firing of the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent by one EventLoop tick when using the Http2FrameCodec to ensure all handlers are added to the pipeline before the event is passed through it.
This is needed to workaround a race that could happen when the preface is send in handlerAdded(...) but a later handler wants to act on the event.
Modifications:
Offload firing of the event to the EventExecutor.
Result:
Fixes https://github.com/netty/netty/issues/9432.
Motivation:
306299323c introduced some code change to move the responsibility of creating the stream for the upgrade to Http2FrameCodec. Unfortunaly this lead to the situation of having newStream().setStreamAndProperty(...) be called twice. Because of this we only ever saw the channelActive(...) on Http2StreamChannel but no other events as the mapping was replaced on the second newStream().setStreamAndProperty(...) call.
Beside this we also did not use the correct handler for the upgrade stream in some cases
Modifications:
- Just remove the Http2FrameCodec.onHttpClientUpgrade() method and so let the base class handle all of it. The stream is created correctly as part of the ConnectionListener implementation of Http2FrameCodec already.
- Consolidate logic of creating stream channels
- Adjust unit test to capture the bug
Result:
Fixes https://github.com/netty/netty/issues/9395
Motivation:
When using the HTTP/2 multiplex implementation we need to ensure we correctly drain the buffered inbound data even if the RecvByteBufallocator.Handle tells us to stop reading in between.
Modifications:
Correctly loop through the buffered inbound data until the user does stop to request from it.
Result:
Fixes https://github.com/netty/netty/issues/9387.
Co-authored-by: Bryce Anderson <banderson@twitter.com>
Motivation:
We can easily reuse the Http2FrameStreamEvent instances and so reduce GC pressure as there may be multiple events per streams over the life-time.
Modifications:
Reuse instances
Result:
Less allocations
Motivation:
At the moment we lookup the ChannelHandlerContext used in Http2StreamChannelBootstrap each time the open(...) method is invoked. This is not needed and we can just cache it for later usage.
Modifications:
Cache ChannelHandlerContext in volatile field.
Result:
Speed up open(...) method implementation when called multiple times
Motivation:
If a read triggers a AbstractHttp2StreamChannel to close we can
get an NPE in the read loop.
Modifications:
Make sure that the inboundBuffer isn't null before attempting to
continue the loop.
Result:
No NPE.
Fixes#9337
Motivation:
The Http2FrameCodec should be responsible to create the upgrade stream.
Modifications:
Move code to create stream to Http2FrameCodec
Result:
More correct responsibility
Motivation:
Mark Http2StreamChannelBootstrap.open0(...) as deprecated as the user should not use it. It was marked as public by mistake.
Modifications:
Add deprecation warning.
Result:
User will be aware the method should not be used directly.
Motivation:
There are situations where the user may want to be more flexible when to send the PING acks for various reasons or be able to attach a listener to the future that is used for the ping ack. To be able to do so we should allow to manage the acks manually.
Modifications:
- Add constructor to DefaultHttp2ConnectionDecoder that allows to disable the automatically sending of ping acks (default is to send automatically to not break users)
- Add methods to AbstractHttp2ConnectionHandlerBuilder (and sub-classes) to either enable ot disable auto acks for pings
- Make DefaultHttp2PingFrame constructor public that allows to write acks.
- Add unit test
Result:
More flexible way of handling acks.
Motivation:
Netty homepage(netty.io) serves both "http" and "https".
It's recommended to use https than http.
Modification:
I changed from "http://netty.io" to "https://netty.io"
Result:
No effects.
Motivation:
Http2ConnectionHandler (and sub-classes) allow to configure a graceful shutdown timeout but only apply it if there is at least one active stream. We should always apply the timeout. This is also true when we try to send a GO_AWAY and close the connection because of an connection error.
Modifications:
- Always apply the timeout if one is configured
- Add unit test
Result:
Always respect gracefulShutdownTimeoutMillis
Motivation:
b3dba317d7 introduced the concept of Http2SettingsReceivedConsumer but did not correctly inplement DecoratingHttp2ConnectionEncoder.consumeRemoteSettings(...).
Modifications:
- Add missing `else` around the throws
- Add unit tests
Result:
Correctly implement DecoratingHttp2ConnectionEncoder.consumeRemoteSettings(...)
Motivation
The nice change made by @carl-mastrangelo in #9307 for lookup-table
based HPACK Huffman decoding can be simplified a little to remove the
separate flags field and eliminate some intermediate operations.
Modification
Simplify HpackHuffmanDecoder::decode logic including de-dup of the
per-nibble part.
Result
Less code, possibly better performance though not noticeable in a quick
benchmark.
Motivation:
We don't need the extra ChannelPromise when writing headers anymore in Http2FrameCodec. This also means we cal re-use a ChannelFutureListener and so not need to create new instances all the time.
Modifications:
- Just pass the original ChannelPromise when writing headers
- Reuse the ChannelFutureListener
Result:
Two less objects created when writing headers for an not-yet created stream.
Motivation:
ff0045e3e1 changed HpackHuffmanDecoder to use a lookup-table which greatly improved performance. We can squeeze out another 3% win by using an ByteProcessor which will reduce the number of bound-checks / reference-count-checks needed by processing byte-by-byte.
Modifications:
Implement logic with ByteProcessor
Result:
Another ~3% perf improvement which shows up when using h2load to simulate load.
`h2load -c 100 -m 100 --duration 60 --warm-up-time 10 http://127.0.0.1:8080`
Before:
```
finished in 70.02s, 620051.67 req/s, 20.70MB/s
requests: 37203100 total, 37203100 started, 37203100 done, 37203100 succeeded, 0 failed, 0 errored, 0 timeout
status codes: 37203100 2xx, 0 3xx, 0 4xx, 0 5xx
traffic: 1.21GB (1302108500) total, 41.84MB (43872600) headers (space savings 90.00%), 460.24MB (482598600) data
min max mean sd +/- sd
time for request: 404us 24.52ms 15.93ms 1.45ms 87.90%
time for connect: 0us 0us 0us 0us 0.00%
time to 1st byte: 0us 0us 0us 0us 0.00%
req/s : 6186.64 6211.60 6199.00 5.18 65.00%
```
With this change:
```
finished in 70.02s, 642103.33 req/s, 21.43MB/s
requests: 38526200 total, 38526200 started, 38526200 done, 38526200 succeeded, 0 failed, 0 errored, 0 timeout
status codes: 38526200 2xx, 0 3xx, 0 4xx, 0 5xx
traffic: 1.26GB (1348417000) total, 42.39MB (44444900) headers (space savings 90.00%), 466.25MB (488893900) data
min max mean sd +/- sd
time for request: 370us 24.89ms 15.52ms 1.35ms 88.02%
time for connect: 0us 0us 0us 0us 0.00%
time to 1st byte: 0us 0us 0us 0us 0.00%
req/s : 6407.06 6435.19 6419.74 5.62 67.00%
```
Motivation:
In the latest release we introduced Http2MultiplexHandler as a replacement of Http2MultiplexCodec. This did split the frame parsing from the multiplexing to allow a more flexible way to handle frames and to make the code cleaner. Unfortunally we did miss to special handle this in Http2ServerUpgradeCodec and so did not correctly add Http2MultiplexHandler to the pipeline before calling Http2FrameCodec.onHttpServerUpgrade(...). This did lead to the situation that we did not correctly receive the event on the Http2MultiplexHandler and so did not correctly created the Http2StreamChannel for the upgrade stream. Because of this we ended up with an NPE if a frame was dispatched to the upgrade stream later on.
Modifications:
- Correctly add Http2MultiplexHandler to the pipeline before calling Http2FrameCodec.onHttpServerUpgrade(...)
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9314.
Motivation:
b3dba317d7 added AbstractHttp2ConnectionBuilder.autoAckSettingsFrame(...) as protected method and made it public for Http2MultiplexCodecBuilder. Unfortunally it did miss to also make it public in Http2FrameCodecBuilder
Modifications:
Correctly override autoAckSettingsFrame in Http2FrameCodecBuilder and so make it usable when building Http2FrameCodec.
Result:
Be able to also configure autoAckSettingsFrame when Http2FrameCodec is used.
Motivation:
There is some manual coping of elements of Collections which can be replaced by Collections.addAll(...) and also some unnecessary semicolons.
Modifications:
- Simplify branches
- Use Collections.addAll
- Code cleanup
Result:
Code cleanup
Motivation:
We should not propage Http2WindowUpdateFrames to the child channels at all as these are not really use-ful and should not be flow-controlled via `read()` anyway. In the other hand Http2ResetFrame is very useful but should be propagated via an user event so the user is aware of it directly even if the user stops reading.
Modifications:
- Dont propagate Http2WindowUpdateFrames when using Http2MultiplexHandler
- Use user event for Http2ResetFrame when using Http2MultiplexHandler
- Adjust javadoc of Http2MultiplexHandler
- Add unit tests
Result:
Fixes https://github.com/netty/netty/pull/8889 and https://github.com/netty/netty/pull/7635
Motivation:
Http2MultiplexCodec and Http2MultiplexHandler had a very strong coupling with Http2FrameCodec which we can reduce easily. The end-goal should be to have no coupling at all.
Modifications:
- Reduce coupling by move some common logic to Http2CodecUtil
- Move logic to check if a stream may have existed before to Http2FrameCodec
- Use ArrayDeque as replacement for custom double-linked-list which makes the code a lot more readable
- Use WindowUpdateFrame to signal consume bytes (just as users do when they use Http2FrameCodec directly)
Result:
Less coupling and cleaner code.
Motivation:
In the past we had the following class hierarchy:
Http2ConnectionHandler --- Http2FrameCodec -- Http2MultiplexCodec
This hierarchy makes it impossible to plug in any code that would like to act on Http2Frame and Http2StreamFrame which can be quite useful for various situations (like metrics, logging etc). Beside this it also made the implementtion very hacky. To allow easier maintainance and also allow more flexible costumizations we should split Http2MultiplexCodec and Http2FrameCode.
Modifications:
- Introduce Http2MultiplexHandler (which is a replacement for Http2MultiplexCodec when used together with Http2FrameCodec)
- Mark Http2MultiplexCodecBuilder and Http2MultiplexCodec as deprecated. People should use Http2FrameCodecBuilder / Http2FrameCodec together with Http2MultiplexHandlder in the future
- Adjust / Add tests
- Adjust examples
Result:
More flexible usage possible and less hacky / coupled implementation for http2 multiplexing
Motivation:
For HTTP/2 messages with multiple cookies HttpConversionUtil.addHttp2ToHttpHeaders spends a good portion of time creating throwaway StringBuilders.
Modification:
Handle cookies lazily by using a ThreadLocal StringBuilder and then converting it to the H1 header at the end.
Result:
Less allocations.
Motivation:
f945a071db decoupled the writability state from the flow controller but could lead to the situation of a lot of writability updates events were propagated to the child channels. This change ensure we only take into account if the parent channel becomes writable again before we try to set the child channels to writable.
Modifications:
Only listen for channel writability changes for if the parent channel becomes writable again.
Result:
Less writability updates.
Motivation:
We should decouple the writability state of the http2 child channels from the flow-controller and just tie it to its own pending bytes counter that is decremented by the parent Channel once the bytes were written.
Modifications:
- Decouple writability state of child channels from flow-contoller
- Update tests
Result:
Less coupling and more correct behavior. Fixes https://github.com/netty/netty/issues/8148.
Motivation:
b4e3c12b8e introduced code to avoid coupling
close() to graceful close. It also added some code which attempted to infer when
a graceful close was being done in writing of a GOAWAY to preserve the
"connection is closed when all streams are closed behavior" for the child
channel API. However the implementation was too overzealous and may preemptively
close the connection if there are not currently any open streams (and close if
there are any frames which create streams in flight).
Modifications:
- Decouple writing a GOAWAY from trying to infer if a graceful close is being
done and closing the connection. Even if we could enhance this logic (e.g.
wait to close until the second GOAWAY with no error) it is possible the user
doesn't want the connection to be closed yet. We can add a means for the codec
to orchestrate the graceful close in the future (e.g. write some special "close
the connection when all streams are closed") but for now we can just let the
application handle this.
Result:
Fixes https://github.com/netty/netty/issues/9207
Motivation:
The first final version of GraalVM was released which deprecated some flags. We should use the new ones.
Modifications:
Removes the use of deprecated GraalVM native-image flags
Adds a flag to initialize netty at build time.
Result:
Do not use deprecated flags
Motivation:
OOME is occurred by increasing suppressedExceptions because other libraries call Throwable#addSuppressed. As we have no control over what other libraries do we need to ensure this can not lead to OOME.
Modifications:
Only use static instances of the Exceptions if we can either dissable addSuppressed or we run on java6.
Result:
Not possible to OOME because of addSuppressed. Fixes https://github.com/netty/netty/issues/9151.
Motivation:
Http2MultiplexCodec.DefaultHttp2StreamChannel currently only act on ClosedChannelException exceptions when checking for isAutoClose(). We should widen the scope here to IOException to be more consistent with AbstractChannel.
Modifications:
Replace instanceof ClosedChannelException with instanceof IOException
Result:
More consistent handling of isAutoClose()
Motivation:
GraalVM native images are a new way to deliver java applications. Netty is one of the most popular libraries however there are a few limitations that make it impossible to use with native images out of the box. Adding a few metadata (in specific modules will allow the compilation to success and produce working binaries)
Modification:
Added properties files in `META-INF` and substitutions classes (under `internal.svm`) will solve the compilation issues. The substitutions classes are not visible and do not have a public constructor so they are not visible to end users.
Result:
Fixes#8959
This fix is very conservative as it applies the minimum config required to build:
* pure netty servers
* vert.x applications
* grpc applications
The build is having trouble due to checkstyle which does not seem to be able to find the copyright notice on property files.
Motivation:
Http2ConnectionHandler#close(..) always runs the GOAWAY and graceful close
logic. This coupling means that a user would have to override
Http2ConnectionHandler#close(..) to modify the behavior, and the
Http2FrameCodec and Http2MultiplexCodec are not extendable so you cannot
override at this layer. Ideally we can totally decouple the close(..) of the
transport and the GOAWAY graceful closure process completely, but to preserve
backwards compatibility we can add an opt-out option to decouple where the
application is responsible for sending a GOAWAY with error code equal to
NO_ERROR as described in https://tools.ietf.org/html/rfc7540#section-6.8 in
order to initiate graceful close.
Modifications:
- Http2ConnectionHandler supports an additional boolean constructor argument to
opt out of close(..) going through the graceful close path.
- Http2FrameCodecBuilder and Http2MultiplexCodec expose
gracefulShutdownTimeoutMillis but do not hook them up properly. Since these
are already exposed we should hook them up and make sure the timeout is applied
properly.
- Http2ConnectionHandler's goAway(..) method from Http2LifecycleManager should
initiate the graceful closure process after writing a GOAWAY frame if the error
code is NO_ERROR. This means that writing a Http2GoAwayFrame from
Http2FrameCodec will initiate graceful close.
Result:
Http2ConnectionHandler#close(..) can now be decoupled from the graceful close
process, and immediately close the underlying transport if desired.
Motivation:
Http2FrameCodec currently fails the write promise associated with creating a
stream with a Http2NoMoreStreamIdsException. However this means the user code
will have to listen to all write futures in order to catch this scenario which
is the same as receiving a GOAWAY frame. We can also simulate receiving a GOAWAY
frame from our remote peer and that allows users to consolidate graceful close
logic in the GOAWAY processing.
Modifications:
- Http2FrameCodec should simulate a DefaultHttp2GoAwayFrame when trying to
create a stream but the stream IDs have been exhausted.
Result:
Applications can rely upon GOAWAY for graceful close processing instead of also
processing write futures.
Motivaiton:
DefaultHttp2ConnectionEncoder uses SimpleChannelPromiseAggregator to combine two
operations into a single future status. However it directly uses the
SimpleChannelPromiseAggregator object instead of using the newPromise() method
in one case. This may result in premature completion of the aggregated future.
Modifications:
- DefaultHttp2ConnectionEncoder to use
SimpleChannelPromiseAggregator#newPromise() instead of directly using the
SimpleChannelPromiseAggregator instance when writing the settings ACK frame
Result:
More correct status for the SETTING ACK frame writing when auto settings ACK is
disabled.
Motivation:
The HTTP/2 codec will synchronously respond to a SETTINGS frame with a SETTINGS
ACK before the application sees the SETTINGS frame. The application may need to
adjust its state depending upon what is in the SETTINGS frame before applying
the remote settings and responding with an ACK (e.g. to adjust for max
concurrent streams). In order to accomplish this the HTTP/2 codec should allow
for the application to opt-in to sending the SETTINGS ACK.
Modifications:
- DefaultHttp2ConnectionDecoder should support a mode where SETTINGS frames can
be queued instead of immediately applying and ACKing.
- DefaultHttp2ConnectionEncoder should attempt to poll from the queue (if it
exists) to apply the earliest received but not yet ACKed SETTINGS frame.
- AbstractHttp2ConnectionHandlerBuilder (and sub classes) should support a new
option to enable the application to opt-in to managing SETTINGS ACK.
Result:
HTTP/2 allows for asynchronous SETTINGS ACK managed by the application.
Motivation:
com.puppycrawl.tools checkstyle < 8.18 was reported to contain a possible security flaw. We should upgrade.
Modifications:
- Upgrade netty-build and checkstyle.
- Fix checkstyle errors
Result:
Fixes https://github.com/netty/netty/issues/8968.
Motivation:
PromiseCombiner is not thread-safe and even assumes all added Futures are using the same EventExecutor. This is kind of fragile as we do not enforce this. We need to enforce this contract to ensure it's safe to use and easy to spot concurrency problems.
Modifications:
- Add new contructor to PromiseCombiner that takes an EventExecutor and deprecate the old non-arg constructor.
- Check if methods are called from within the EventExecutor thread and if not fail
- Correctly dispatch on the right EventExecutor if the Future uses a different EventExecutor to eliminate concurrency issues.
Result:
More safe use of PromiseCombiner + enforce correct usage / contract.
Motivation:
When more than one connection header is present in h2c upgrade request, upgrade fails. This is to fix that.
Modification:
In HttpServerUpgradeHandler's upgrade() method, check whether any of the connection header value is upgrade, not just the first header value which might return a different value other than upgrade.
Result:
Fixes#8846.
With this PR, now when multiple connection headers are sent with the upgrade request, upgrade will not fail.
Motivation:
We can replace some "hand-rolled" integer checks with our own static utility method to simplify the code.
Modifications:
Use methods provided by `ObjectUtil`.
Result:
Cleaner code and less duplication
Motivation:
We need to update to a new checkstyle plugin to allow the usage of lambdas.
Modifications:
- Update to new plugin version.
- Fix checkstyle problems.
Result:
Be able to use checkstyle plugin which supports new Java syntax.
Motivation:
When a write error happens during writing of flowcontrolled data frames we miss to correctly detect this in the write loop which may result in an infinite loop as we will never detect that the frame should be removed from the queue.
Modifications:
- When we fail a flowcontrolled data frame we ensure that the next frame.write(...) call will signal back that the whole frame was handled and so can be removed.
- Add unit test.
Result:
Fixes https://github.com/netty/netty/issues/8707.
Motivation:
In Http2FrameCodec we made the incorrect assumption that we can only have 1 buffered outboundstream as maximum. This is not correct and we need to account for multiple buffered streams.
Modifications:
- Use a map to allow buffer multiple streams
- Add unit test.
Result:
Fixes https://github.com/netty/netty/issues/8692.
Motiviation:
Http2FrameCodecTest and Http2MultiplexCodecTest were quite fragile and often not went through the whole pipeline which made testing sometimes hard and error-prone.
Modification:
- Refactor tests to have data flow through the whole pipeline and so made the test more robust (by testing the while implementation).
Result:
Easier to write tests for the codecs in the future and more robust testing in general.
Beside this it also fixes https://github.com/netty/netty/issues/6036.
Motivation:
We should always call ctx.read() even when AUTO_READ is false as flow-control is enforced by the HTTP/2 protocol.
See also https://tools.ietf.org/html/rfc7540#section-5.2.2.
We already did this before but not explicit and only did so because of some implementation details of ByteToMessageDecoder. It's better to be explicit here to not risk of breakage later on.
Modifications:
- Ensure we always call ctx.read() when AUTO_READ is false
- Add unit test.
Result:
No risk of staling the connection when HTTP/2 is used.
Motivation:
In windows if the project is in a path that contains whitespace,
resources cannot be accessed and tests fail.
Modifications:
Adds ResourcesUtil.java in netty-common. Tests use ResourcesUtil.java to access a resource.
Result:
Being able to build netty in a path containing whitespace
Motivation:
9f9aa1a did some changes related to fixing how we handle ctx.read() in child channel but did incorrectly change some assert.
Modifications:
Fix assert to be correct.
Result:
Code does not throw an AssertionError due incorrect assert check.
Motivation:
Most of the maven modules do not explicitly declare their
dependencies and rely on transitivity, which is not always correct.
Modifications:
For all maven modules, add all of their dependencies to pom.xml
Result:
All of the (essentially non-transitive) depepdencies of the modules are explicitly declared in pom.xml
Motivation:
We did not correct respect ctx.read() calls while processing a read for a child Channel. This could lead to read stales when auto read is disabled and no other read was requested.
Modifications:
- Keep track of extra read() calls while processing reads
- Add unit tests that verify that read() is respected when triggered either in channelRead(...) or channelReadComplete(...)
Result:
Fixes https://github.com/netty/netty/issues/8209.
Motivation
DefaultHttp2FrameReader currently does a fair amount of "intermediate"
slicing which can be avoided.
Modifications
Avoid slicing the input buffer in DefaultHttp2FrameReader until
necessary. In one instance this also means retainedSlice can be used
instead (which may also avoid allocating).
Results
Less allocations when using http2.
Motivation:
When the DefaultHttp2ConnectionEncoder writes the initial headers for a new
locally created stream we create the stream in the half-closed state if the
end-stream flag is set which signals to the life cycle manager that the headers
have been sent. However, if we synchronously fail to write the headers the
life cycle manager then sends a RST_STREAM on our behalf which is a connection
level PROTOCOL_ERROR because the peer sees the stream in an IDLE state.
Modification:
Don't open the stream in the half-closed state if the end-stream flag is
set and let the life cycle manager take care of it.
Result:
Cleaner state management in the DefaultHttp2ConnectionEncoder.
Fixes#8434.
Motivation:
The `Http2StreamFrameToHttpObjectCodec` is marked `@Sharable` but mutates
an internal `HttpScheme` field every time it is added to a pipeline.
Modifications:
Instead of storing the `HttpScheme` in the handler we store it as an
attribute on the parent channel.
Result:
Fixes#8480.
Motivation:
There are log messages emitted from Http2ConnectionDecoder of the form
```
INF i.n.h.c.h.DefaultHttp2ConnectionDecoder ignoring HEADERS frame for stream RST_STREAM sent. {}
```
Modifications:
Remove the trailing `{}` in the log message that doesn't have a value.
Result:
Log messages no longer have a trailing `{}`.
Motivation:
When writing an HTTP/2 HEADERS with END_STREAM=1, the application expects
the stream to be closed afterward. However, the write can fail locally
due to HPACK encoder and similar. When that happens we need to make sure
to issue a RST_STREAM otherwise the stream can be closed locally but
orphaned remotely. The RST_STREAM is typically handled by
Http2ConnectionHandler.onStreamError, which will only send a RST_STREAM
if that stream still exists locally.
There are two possible flows for trailers, one handled immediately and
one going through the flow controller. Previously they behaved
differently, with the immedate code calling the error handler after
closing the stream. The immediate code also used a listener for calling
closeStreamLocal while the flow controlled code did so immediately after
the write.
The two code paths also differed in their VoidChannelPromise handling,
but both were broken. The immediate code path called unvoid() only if
END_STREAM=1, however it could always potentially add a listener via
notifyLifecycleManagerOnError(). And the flow controlled code path
unvoided incorrectly, changing the promise completion behavior. It also
passed the wrong promise to closeStreamLocal() in FlowControlledBase.
Modifications:
Move closeStreamLocal handling after calls to onError. This is the
primary change.
Now call closeStreamLocal immediately instead of when the future
completes. This is the more likely correct behavior as it matches that
of DATA frames.
Fix all the VoidChannelPromise handling.
Result:
Http2ConnectionHandler.onStreamError sees the same state as the remote
and issues a RST_STREAM, properly cleaning up the stream.
Motivation:
Http2MultiplexCodec queues data internally if data is delivered from the
parent channel but the child channel did not request data. If the parent
channel notifies of a stream closure it is possible data in the queue
will be discarded before closing the channel.
Http2MultiplexCodec interacts with RecvByteBufAllocator to control the
child channel's demand for read. However it currently only ever reads a
maximum of one time per loop. This can thrash the read loop and bloat
the call stack if auto read is on, because channelReadComplete will
re-enter the read loop synchronously, and also neglect to deliver data
during the parent's read loop (if it is active). This also meant the
readPendingQueue was not utilized as originally intended (to extend the
child channel's read loop during the parent channel's read loop if
demand for data still existed).
Modifications:
- Modify the child channel's read loop to respect the
RecvByteBufAllocator, and append to the parents readPendingQueue if
appropriate.
- Stream closure notification behaves like EPOLL and KQUEUE transports
and reads all queued data, because the data is already queued in memory
and it is known there will be no more data. This will also replenish the
connection flow control window which may otherwise be constrained by a
closed stream.
Result:
More correct read loop and less risk of dropping data.
Motivation:
When a Http2MultiplexCodec stream channel fails to write the first
HEADERS it will forcibly close, and that will trigger sending a
RST_STREAM, which is commonly a connection level protocol error. This is
because it has what looks like a valid stream id, but didn't check with
the connection as to whether the stream may have actually existed.
Modifications:
Instead of checking if the stream was just a valid looking id ( > 0) we
check with the connection as to whether it may have existed at all.
Result:
We no longer send a RST_STREAM frame from Http2MultiplexCodec for idle
streams.
Motivation:
The Http2Connection state is updated by the DefaultHttp2ConnectionDecoder after the frame listener is notified of the goaway frame. If the listener sends a frame synchronously this means the connection state will not know about the goaway it just received and we may send frames that are not allowed on the connection. This may also mean a stream object is created but it may never get taken out of the stream map unless some other event occurs (e.g. timeout).
Modifications:
- The Http2Connection state should be updated before the listener is notified of the goaway
- The Http2Connection state modification and validation should be self contained when processing a goaway instead of partially in the decoder.
Result:
No more creating streams and sending frames after a goaway has been sent or received.
Motivation:
If the local endpoint receives a GO_AWAY frame and then tries to write a stream with a streamId higher than the last know stream ID we will throw a connection error. This results in the local peer sending a GO_AWAY frame to the remote peer, but this is not necessary as the error can be isolated to the local endpoint and communicated via the ChannelFuture return value.
Modifications:
- Instead of throwing a connection error, throw a stream error that simulates the peer receiving the stream and replying with a RST
Result:
Connections are not closed abruptly when trying to create a stream on the local endpoint after a GO_AWAY frame is received.
Motivation:
If a write fails for a Http2MultiplexChannel stream channel, the channel
may be forcibly closed, but only after the promise has been failed. That
means continuations attached to the promise may see the channel in an
inconsistent state of still being open and active.
Modifications:
Move the satisfaction of the promise to after the channel cleanup logic
runs.
Result:
Listeners attached to the future that resulted in a Failed write will
see the stream channel in the correct state.
Motivation:
The HTTP/2 spec dictates that invalid pseudo-headers should cause the
request/response to be treated as malformed (8.1.2.1), and the recourse
for that is to treat the situation as a stream error of type
PROTOCOL_ERROR (8.1.2.6). However, we're treating them as a connection
error with the connection being immediately torn down and the HPACK
state potentially being corrupted.
Modifications:
The HpackDecoder now throws a StreamException for validation failures
and throwing is deffered until the end of of the decode phase to ensure
that the HPACK state isn't corrupted by returning early.
Result:
Behavior more closely aligned with the HTTP/2 spec.
Fixes#8043.
Motivation:
We deviate from the AbstractChannel implementation on deregistration by
failing the provided promise if the channel is already deregistered. In
contrast, AbstractChannel will always set the promise to successfully
done.
Modification:
Change the
Http2MultiplexCodec.DefaultHttp2StreamChannel.Http2ChannelUnsafe to
always set the promise provided to deregister as done as is the
case in AbstractChannel.
Motivation:
There is an inconsistency between the order of events in the
StreamChannel implementation in Http2MultiplexCodec and other Channel
implementations that extend AbstractChannel where channelInactive and
channelUnregistered events are not performed 'later'. This can cause an
unexected order of events for ChannelHandler implementations that call
Channel.close() in response to some event.
Modification:
The Http2MultiplexCodec.DefaultHttp2StreamChannel.Http2ChannelUnsafe was
modified to bounce the deregistration and channelInactive events through
the parent channels EventLoop.
Result:
Stream events are now in the proper order.
Fixes#8018.
Motivation:
Http2MultiplexCodec doesn't currently have an API for using the response
of a h2c upgrade request.
Modifications:
Add a new API to the Http2MultiplexCodecBuilder which allows for setting
an upgrade handler and wire it into the Http2MultiplexCodec
implementation.
Result:
When using the Http2MultiplexCodec with h2c upgrades the upgrade handler
will get added to the Http2StreamChannel which represents the
half-closed (local) response of stream 1. It is then up to the user to
manage the transition from the IO channel pipeline configuration
necessary for making the h2c upgrade request to a form where it can read
the response from the new stream channel.
Fixes#7947.
Motivation:
The `ByteBuffer emptyPingBuf()` method of Http2CodecUtils is has been dead
code since DefaultHttp2PingFrame switched from using a ByteBuf to represent
the 8 octets to a long.
Modifications:
Remove the method and the unused static ByteBuf.
Result:
Less dead code.
Fixes#8002
Motivation:
This is a followup for #7860. In the fix for #7860 we only partly fixed the problem as Http2UnknownFrame did not correctly extend HttpStreamFrame and so only worked when using the Http2FrameCodec. We need to have it extend HttpStreamFrame as otherwise Http2MultiplexCodec will reject to handle it correctly.
Modifications:
- Let Http2UnknownFrame extend HttpStreamFrame
- Add unit tests for writing and reading Http2UnkownFrame instances when the Http2MultiplexCodec is used.
Result:
Fixes https://github.com/netty/netty/issues/7969.
Motivation:
When a sender sends too large of headers it should not unnecessarily
kill the connection, as killing the connection is a heavy-handed
solution while SETTINGS_MAX_HEADER_LIST_SIZE is advisory and may be
ignored.
The maxHeaderListSizeGoAway limit in HpackDecoder is unnecessary because
any headers causing the list to exceeding the max size can simply be
thrown away. In addition, DefaultHttp2FrameReader.HeadersBlockBuilder
limits the entire block to maxHeaderListSizeGoAway. Thus individual
literals are limited to maxHeaderListSizeGoAway.
(Technically, literals are limited to 1.6x maxHeaderListSizeGoAway,
since the canonical Huffman code has a maximum compression ratio of
.625. However, the "unnecessary" limit in HpackDecoder was also being
applied to compressed sizes.)
Modifications:
Remove maxHeaderListSizeGoAway checking in HpackDecoder and instead
eagerly throw away any headers causing the list to exceed
maxHeaderListSize.
Result:
Fewer large header cases will trigger connection-killing.
DefaultHttp2FrameReader.HeadersBlockBuilder will still kill the
connection when maxHeaderListSizeGoAway is exceeded, however.
Fixes#7887
Motivation:
Integer autoboxing in this class (and possibly also the varargs arrays)
showed non-negligible CPU and garbage contribution when profiling a gRPC
service. grpc-java currently hardcodes use of Http2FrameLogger, set at
DEBUG level.
Modifications:
Wrap offending log statements in conditional blocks.
Result:
Garbage won't be produced by Http2FrameLogger when set to a disabled
logging level.
Motivation:
Streams can be deregistered so we can't assume their existence in the stream map.
Modifications:
Add a null-check in case a stream has been deregistered.
Result:
Fixes#7898.
Motivation:
We incorrectly called frame.release() in onHttp2GoAwayFrame which could lead to IllegalReferenceCountExceptions. The call of release() is inappropriate because the fireChannelRead() in onHttp2Frame() will handle it.
Modifications:
- Not call frame.release()
- Add a unit test
Result:
Fxies https://github.com/netty/netty/issues/7892.
It is possible to create streams in the half-closed state where the
stream state doesn't reflect that the request headers have been sent by
the client or the server hasn't received the request headers. This
state isn't possible in the H2 spec as a half closed stream must have
either received a full request or have received the headers from a
pushed stream. In the current implementation, this can cause the stream
created as part of an h2c upgrade request to be in this invalid state
and result in the omission of RST frames as the client doesn't believe
it has sent the request to begin with.
Modification:
The `DefaultHttp2Connection.activate` method checks the state and
modifies the status of the request headers as appropriate.
Result:
Fixes#7847.
Motivation:
When connecting to an HTTP/2 server that did not set any value for the
SETTINGS_MAX_HEADER_LIST_SIZE in the settings frame, the netty client was
imposing an arbitrary maximum header list size of 8kB. There should be no need
for the client to enforce such a limit if the server has not specified any
limit. This caused an issue for a grpc-java client that needed to send a large
header to a server via an Envoy proxy server. The error condition is
demonstrated here: https://github.com/JLofgren/demo-grpc-java-bug-4284
Fixes grpc-java issue #4284 - https://github.com/grpc/grpc-java/issues/4284
and netty issue #7825 - https://github.com/netty/netty/issues/7825
Modifications:
In HpackEncoder use MAX_HEADER_LIST_SIZE as default maxHeader list size.
Result:
HpackEncoder will only enforce a max header list size if the server has
specified a limit in its settings frame.
Motivation:
We should allow to write Http2UnkownFrame to allow custom extensions.
Modifications:
Allow to write Http2UnkownFrame
Add unit test
Result:
Fixes https://github.com/netty/netty/issues/7860.
Motivation:
There is a race between both flushing the upgrade response and receiving
more data before the flush ChannelPromise can fire and reshape the
pipeline. Since We have already committed to an upgrade by writing the
upgrade response, we need to be immediately prepared for handling the
next protocol.
Modifications:
The pipeline reshaping logic in HttpServerUpgradeHandler has been moved
out of the ChannelFutureListener attached to the write of the upgrade
response and happens immediately after the writeAndFlush call, but
before the method returns.
Result:
The pipeline is no longer subject to receiving more data before the
pipeline has been reformed.
Motivation:
We did not correctly set the stream id in the headers of HttpMessage when converting a Http2HeadersFrame. This is based on https://github.com/netty/netty/pull/7778 so thanks to @jprante.
Modifications:
- Correctly set the id when possible in the header.
- Add test case
Result:
Correctly include stream id.
Motivation:
Allow the observation of SETTINGS frame by other handlers in the pipeline. For my particular use case this allows me to observe the value of MAX_CONCURRENT_STREAMS for a ChannelPool abstraction that supports HTTP/2 multiplexing. Beside this also forward GOAWAY frames.
Modification:
Always forward SETTINGS and GOAWAY frames
Result:
Settings / Goaway can now be observed in the parent channel. Previously it was not possible (to my knowledge) to capture the settings when using Http2MultiplexCodec.
Motivation:
At the moment we use a ByteBuf as the payload for a http2 frame. This complicates life-time management a lot with no real gain and also may produce more objects then needed. We should just use a long as it is required to be 8 bytes anyway.
Modifications:
Use long for ping payloads.
Result:
Fixes [#7629].
Motivation:
Reflective setAccessible(true) will produce scary warnings on the console when using java9+, while netty still works. That said users may feel uncomfortable with these warnings, we should not try to do it by default when using java9+.
Modifications:
Add io.netty.tryReflectionSetAccessible system property which controls if setAccessible(...) will be used. By default it will bet set to false when using java9+.
Result:
Fixes [#7254].
Motivation:
According to the spec:
All pseudo-header fields MUST appear in the header block before regular
header fields. Any request or response that contains a pseudo-header
field that appears in a header block after
a regular header field MUST be treated as malformed (Section 8.1.2.6).
Pseudo-header fields are only valid in the context in which they are defined.
Pseudo-header fields defined for requests MUST NOT appear in responses;
pseudo-header fields defined for responses MUST NOT appear in requests.
Pseudo-header fields MUST NOT appear in trailers.
Endpoints MUST treat a request or response that contains undefined or
invalid pseudo-header fields as malformed (Section 8.1.2.6).
Clients MUST NOT accept a malformed response. Note that these requirements
are intended to protect against several types of common attacks against HTTP;
they are deliberately strict because being permissive can expose
implementations to these vulnerabilities.
Modifications:
- Introduce validation in HPackDecoder
Result:
- Requests with unknown pseudo-field headers are rejected
- Requests with containing response specific pseudo-headers are rejected
- Requests where pseudo-header appear after regular header are rejected
- h2spec 8.1.2.1 pass
Motivation:
We should convert Http2Exceptions that are produced because of STREAM_CLOSED to ClosedChannelException when hand-over to the child channel to make it more consistent with other transports.
Modifications:
- Check if STREAM_CLOSED is used and if so create a new ClosedChannelException (while preserve the original exception as cause) and use it in the child channel
- Ensure STREAM_CLOSED is used in DefaultHttp2RemoteFlowController when writes are failed because of a closed stream.
- Add testcase
Result:
More consistent and correct exception usage.
Motivation:
When checking if a value is present, ReadOnlyHttp2Headers always ignores
case for values.
RFC 7540 says: https://tools.ietf.org/html/rfc7540#section-8.1.2
"header field names are strings of ASCII characters that are compared in a case-insensitive fashion"
But there is no such constraint on header values
Modifications:
Updated ReadOnlyHttp2Headers.contains to compare header value in a
case-sensitive way.
Result:
ReadOnlyHttp2Headers compares header names in a case-insensitive way,
values in a case-sensitive way.
Motivation:
If you test a header value providing a String, contains() returns false.
This is due to the implementation inherited from DefaultHeaders using
the JAVA_HASHER.
JAVA_HASHER.equals returns false because a is a String and b an
AsciiString.
Modifications:
DefaultHttp2Headers overrides contains and uses CASE_SENSITIVE_HASHER.
Result:
You can test a header value with any CharSequence implementation.
Motivation:
The completion order of promises in Http2MultiplexChannel#close should be consistent with that of AbstractChannel. Otherwise this may result in Future listeners seeing incorrect channel state.
Modifications:
Add tests cases.
Result:
Ensure consistent behavior between Http2MultiplexChannel and AbstractChannel.
Motivation:
Calling DefaultHttp2StreamChannel.Unsafe.close(...) multiple times should not fail.
Modification:
- Correctly handle multiple calls to DefaultHttp2StreamChannel.Unsafe.close(...)
- Complete closePromise and promise that is given to close(...) in the correct order.
- Add unit test
Result:
Fixes [#7628] and [#7641]
Motivation:
If DefaultHttp2ConnectionEncoder process outbound operation it sometimes missed to call Http2LifecycleManager.onError(...) when the operation was executed asynchronously.
Modifications:
Make best effort to update flags but still ensure failures are propageted to Http2LifecycleManager.onError(...) in all cases.
Result:
More consistent handling of errors.
Motivation:
Pseudo headers are checked less frequently than normal headers, so
it is more efficient to check the latter first.
Modifications:
Swap the order of the check, and fix minor formatting
Result:
Possibly more efficient header checks
Motivation:
We can just implement the interfaces directly and so reduce object creation in DefaultHttp2RemoteFlowController.
Modifications:
Directly implement the interfaces.
Result:
Less object creation.
Motivation:
When part of a HTTP/2 StreamChannel the Http2StreamChannel.isOpen() / isActive() should report false within a call to a ChannelInboundHandlers channelInactive() method.
Modifications:
Fullfill promise before call fireChannelInactive()
Result:
Correctly update state / promise before notify handlers. Fixes [#7638]
Motivation:
With HTTP1, it's very easy to check if a header is present and has a
given value: you can simply invoke
io.netty.handler.codec.http.HttpHeaders#contains(java.lang.CharSequence, java.lang.CharSequence, boolean)
It is not possible to do the same with HTTP2. You have to get the list
of all headers (returned as String) and then iterate over it invoking
String#equals or String#equalsIgnoreCase
Modifications:
I've added io.netty.handler.codec.http2.Http2Headers#contains and
implemented it in DefaultHttp2Headers, EmptyHttp2Headers and ReadOnlyHttp2Headers.
Result:
You can use AsciiString constants to check if a header is present in a
consice and efficient manner.
Motivation:
Usually when using netty exceptions which happen for outbound operations should not be fired through the pipeline but only the ChannelPromise should be failed.
Modifications:
- Change Http2LifecycleManager.onError(...) to take also an boolean that indicate if the error was caused by an outbound operation
- Channel Http2ConnectionHandler.on*Error(...) methods to also take this boolean
- Change Http2FrameCodec to only fire exceptions through the pipeline if these are not outbound operations related
- Add unit test.
Result:
More consistent error handling when using Http2FrameCodec and Http2MultiplexCodec.
Motivation:
Http2MultiplexCodec swallows Http2PingFrames without releasing the payload, resulting in a memory leak.
Modification:
Send unhandled frames down the pipeline for consumption/disposal by another InboundChannelHandler.
Result:
Fixes#7607.
Motivation:
Usages of HttpResponseStatus may result in more object allocation then necessary due to not looking for cached objects and the AsciiString parsing method not being used due to CharSequence method being used instead.
Modifications:
- HttpResponseDecoder should attempt to get the HttpResponseStatus from cache instead of allocating a new object
- HttpResponseStatus#parseLine(CharSequence) should check if the type is AsciiString and redirect to the AsciiString parsing method which may not require an additional toString call
- HttpResponseStatus#parseLine(AsciiString) can be optimized and doesn't require and may not require object allocation
Result:
Less allocations when dealing with HttpResponseStatus.
Motivation:
When we cancel the flowcontrolled writes we did create a new StreamException for each write that was enqueued. Creating Exceptions is very expensive due of filling the stacktrace.
Modifications:
Only create the StreamException once and reuse the same for all the flowcontrolled writes (per stream).
Result:
Less expensive to cancel flowcontrolled writes.
Motivation:
Http2FrameCodec increases the initialWindowSize when the user attempts to increase the connection flow control window. The initialWindowSize should only be touched as a result of a SETTINGS frame, and otherwise may result in flow control getting out of sync with our peer.
Modifications:
- Http2FrameCodec shouldn't update the initialWindowSize when a WindowUpdateFrame is written on the connection channel
Result:
More correct WindowUpdate processing.
Motivation:
HPackDecoder works on entire header block, we shouldn't encounter
incomplete header fields. If we do we should treat it as
a decoding error and according to the specification:
A decoding error in a header block MUST be treated as
a connection error (Section 5.4.1) of type COMPRESSION_ERROR.
Modifications:
* Check final state in HpackDecoder once we've decoded all the data.
Result:
* Throw a connection error if we receive incomplete header fields
* H2spec 4.3 tests all passes
Motivation:
Http2FrameStream#CONNECTION_STREAM is required to identify the
connection stream. However this leads to inconsistent usage from a user
perspective. When a user creates a Http2Frame for a non-connection
stream, the Http2MultiplexCodec automatically sets the stream, and the
user is never exposed to the Http2FrameStream object. However when the
user writes a Http2Frame for a connection stream they are required to
set the Http2FrameStream object. We can remove the Http2FrameStream#CONNECTION_STREAM
and keep the Http2FrameStream object internal, and therefore consistent
between the connection and non-connection use cases.
Modifications:
- Remove Http2FrameStream#CONNECTION_STREAM
- Update Http2FrameCodec to handle Http2Frame#stream() which returns
null
Result:
More consistent usage on http2 parent channel and http2 child channel.
Motivation:
Http2FrameCodecTest#newOutboundStream has a timeout of 1 second and has been observed to timeout on CI servers.
Modifications:
- Increase the timeout to 5 seconds
Result:
Less false positive test failures on CI servers.
Motivation:
HpackDecoder#addHeader takes in the streamId as a parameter but no longer uses it.
Modifications:
- Remove the streamId parameter from HpackDecoder#addHeader
Result:
Less unused parameters in HpackDecoder.
Motivation:
According to the HTTP/2 Spec:
SETTINGS_MAX_HEADER_LIST_SIZE (0x6): This advisory setting informs a
peer of the maximum size of header list that the sender is
prepared to accept, in octets. The value is based on the
uncompressed size of header fields, including the length of the
name and value in octets plus an overhead of 32 octets for each
header field.
We were accounting for the 32 bytes when encoding in HpackEncoder,
but not when decoding in HPackDecoder.
Modifications:
- Add 32 bytes to the header list length for each entry when decoding
with HPackDecoder.
Result:
- We account for the 32 bytes overhead by header entry in HPackDecoder
Motiviation:
In our replace(...) methods we always used validation for the newly created headers while the original headers may not use validation at all.
Modifications:
- Only use validation if the original headers used validation as well.
- Ensure we create a copy of the headers in replace(...).
Result:
Fixes [#5226]
Motivation:
Currently the remote flow controller limits the maximum amount of pending data to Integer.MAX_VALUE. The overflow handling is also not very graceful in that it may lead to infinite loops, or otherwise no progress being made.
Modifications:
- StreamByteDistributor and RemoteFlowController should support pending bytes of type long.
Result:
Fixes https://github.com/netty/netty/issues/4283
Motivation:
http/2 counts header sizes somewhat inconsistently. Sometimes, headers
which are substantively less than the header list size will be measured
as longer than the header list size.
Modifications:
Keep better track of the nameLength of a given name, so that we don't
accidentally end up reusing a nameLength.
Result:
More consistent measurement of header list size.
Fixes#7511.
H2C upgrades should be ineligible for flow control
Motivation:
When the h2c upgrade request is too big, the Http2FrameCodec complains
it's too big for flow control reasons, even though it's ineligible for
flow control.
Modifications:
Specially mark upgrade streams and make Http2FrameCodec know not to try
to flow control on those streams.
Result:
Servers won't barf when they receive an upgrade request with a fat
payload.
[Fixes#7280]
Motivation:
Http2ConnectionHandler uses ctx.fireUserEvent to propagate the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent through the pipeline. This will propagate the event to the next inbound handler in the pipeline. If the user extends Http2ConnectionHandler the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent may be missed and initialization dependent upon this event will not be run.
Modifications:
- Http2ConnectionHandler should use userEventTriggered instead of ctx.fireUserEvent
Result:
Classes that extend Http2ConnectionHandler will see the Http2ConnectionPrefaceAndSettingsFrameWrittenEvent user event.
Automatic-Module-Name entry provides a stable JDK9 module name, when Netty is used in a modular JDK9 applications. More info: http://blog.joda.org/2017/05/java-se-9-jpms-automatic-modules.html
When Netty migrates to JDK9 in the future, the entry can be replaced by actual module-info descriptor.
Modification:
The POM-s are configured to put the correct module names to the manifest.
Result:
Fixes#7218.
Motivation:
HttpConversionUtil#toHttp2Headers has special code to filter the TE header name. However this filtering code may result in adding the <TE, TRAILERS> tuple in scenarios that are not appropriate. For example if a value containing trailers is seen it will be added, but the value could not actually be equal to trailers. Also CSV values are not supported.
Modifications:
- Account for CSV header values
- Account for the value containing 'trailers' but not actually being equal to 'trailers'
Result:
More robust parsing of the TE header.
Modifications:
HttpConversionUtil#toLowercaseMap requires an intermediate List to be allocated. This can be avoided with the recently added value iterator methods.
Modifications:
- Use HttpHeaders#valueCharSequenceIterator instead of getAll
Result:
Less intermediate object allocation and copying.
Motivation:
DefaultHttp2FrameWriter#writeData allocates a DataFrameHeader for each write operation. DataFrameHeader maintains internal state and allocates multiple slices of a buffer which is a maximum of 30 bytes. This 30 byte buffer may not always be necessary and the additional slice operations can utilize retainedSlice to take advantage of pooled objects. We can also save computation and object allocations if there is no padding which is a common case in practice.
Modifications:
- Remove DataFrameHeader
- Add a fast path for padding == 0
Result:
Less object allocation in DefaultHttp2FrameWriter
Motivation:
AbstractByteBuf#readSlice relied upon the bounds checking of the slice operation in order to detect index out of bounds conditions. However the slice bounds checking operation allows for the slice to go beyond the writer index, and this is out of bounds for a read operation.
Modifications:
- AbstractByteBuf#readSlice and AbstractByteBuf#readRetainedSlice should ensure the desired amount of bytes are readable before taking a slice
Result:
No reading of undefined data in AbstractByteBuf#readSlice and AbstractByteBuf#readRetainedSlice.
Motivation:
Netty could handle "connection" or "te" headers more gently when
converting from http/1.1 to http/2 headers. Http/2 headers don't
support single-hop headers, so when we convert from http/1.1 to http/2,
we should drop all single-hop headers. This includes headers like
"transfer-encoding" and "connection", but also the headers that
"connection" points to, since "connection" can be used to designate
other headers as single-hop headers. For the "te" header, we can more
permissively convert it by just dropping non-conforming headers (ie
non-"trailers" headers) which is what we do for all other headers when
we convert.
Modifications:
Add a new blacklist to the http/1.1 to http/2 conversion, which is
constructed from the values of the "connection" header, and stop
throwing an exception when a "te" header is passed with a non-"trailers"
value. Instead, drop all values except for "trailers". Add unit tests
for "connection" and "te" headers when converting from http/1.1 to http/2.
Result:
This will improve the h2c upgrade request, and also conversions from
http/1.1 to http/2. This will simplify implementing spec-compliant
http/2 servers that want to share code between their http/1.1 and http/2
implementations.
[Fixes#7355]
Motivation:
HTTP/2 allows writes of 0 length data frames. However in some cases EMPTY_BUFFER is used instead of the actual buffer that was written. This may mask writes of released buffers or otherwise invalid buffer objects. It is also possible that if the buffer is invalid AbstractCoalescingBufferQueue will not release the aggregated buffer nor fail the associated promise.
Modifications:
- DefaultHttp2FrameCodec should take care to fail the promise, even if releasing the data throws
- AbstractCoalescingBufferQueue should release any aggregated data and fail the associated promise if something goes wrong during aggregation
Result:
More correct handling of invalid buffers in HTTP/2 code.
Motivation:
If a child channel's read is triggered outside the parent channel's read
loop then it is possible a WINDOW_UPDATE will be written, but not
flushed.
If a child channel's beginRead processes data from the inboundBuffer and
then readPending is set to false, which will result in data not being
delivered if in the parent's read loop and more data is attempted to be
delievered to that child channel.
Modifications:
- The child channel must force a flush if a frame is written as a result
of reading a frame, and this is not in the parent channel's read loop
- The child channel must allow a transition from dequeueing from
beginRead into the parent channel's read loop to deliver more data
Result:
The child channel flushes data when reading outside the parent's read
loop, and has frames delivered more reliably.
Motivation:
Http2StreamFrameToHttpObjectCodec was not properly encoding and
decoding 100-Continue HttpResponse/Http2SettingsFrame properly. It was
encoding 100-Continue FullHttpResponse as an Http2SettingFrame with
endStream=true, causing the child channel to terminate. It was not
decoding 100-Continue Http2SettingsFrame (endStream=false) as
FullHttpResponse. This should be fixed as it would cause http2 child
stream to prematurely close, and could cause HttpObjectAggregator to
fail if it's in the pipeline.
Modification:
- Fixed encode() to properly encode 100-Continue FullHttpResponse as
Http2SettingsFrame with endStream=false
- Reject 100-Continue HttpResponse that are NOT FullHttpResponse
- Fixed decode() to properly decode 100-Continue Http2SettingsFrame
(endStream=false) as a FullHttpResponse
- made Http2StreamFrameToHttpObjectCodec sharable so that it can b used
among child streams within the same Http2MultiplexCodec
Result:
Now Http2StreamFrameToHttpObjectCodec should be properly handling
100-Continue responses.
Motivation:
Previously client Http2ConnectionHandler trigger a user event
immediately when the HTTP/2 connection preface is sent. Any attempt to
immediately send a new request could cause the server to terminate the
connection, as it might not have received the SETTINGS frame from the
client. Per RFC7540 Section 3.5, the preface "MUST be followed by a
SETTINGS frame (Section 6.5), which MAY be empty."
(https://tools.ietf.org/html/rfc7540#section-3.5)
This event could be made more meaningful if it also indicates that the
initial client SETTINGS frame has been sent to signal that the channel
is ready to send new requests.
Modification:
- Renamed event to Http2ConnectionPrefaceAndSettingsFrameWrittenEvent.
- Modified Http2ConnectionHandler to trigger the user event only if it
is a client and it has sent both the preface and SETTINGS frame.
Result:
It is now safe to use the event as an indicator that the HTTP/2
connection is ready to send new requests.
Motivation:
A regression was introduced in 86e653e which had the effect that the writability was not updated for a Channel while queueing data in the SslHandler.
Modifications:
- Factor out code that will increment / decrement pending bytes and use it in AbstractCoalescingBufferQueue and PendingWriteQueue
- Add test-case
Result:
Channel writability changes are triggered again.
Motivation:
Objects of java.util.TreeMap or java.util.TreeSet will become
non-Serializable if instantiated with Comparators, which are not also
Serializable. This can result in unexpected and difficult-to-diagnose
bugs.
Modifications:
Implements Serializable for all classes, which implements Comparator.
Result:
Proper Comparators which will not force collections to
non-Serializable mode.
Motivation:
Even if it's a super micro-optimization (most JVM could optimize such
cases in runtime), in theory (and according to some perf tests) it
may help a bit. It also makes a code more clear and allows you to
access such methods in the test scope directly, without instance of
the class.
Modifications:
Add 'static' modifier for all methods, where it possible. Mostly in
test scope.
Result:
Cleaner code with proper 'static' modifiers.
Motivation:
Without a 'serialVersionUID' field, any change to a class will make
previously serialized versions unreadable.
Modifications:
Add missed 'serialVersionUID' field for all Serializable
classes.
Result:
Proper deserialization of previously serialized objects.
Motivation:
During code read of the Netty codebase I noticed that the Netty
HttpServerUpgradeHandler unconditionally sets a Content-Length: 0
header on 101 Switching Protocols responses. This explicitly
contravenes RFC 7230 Section 3.3.2 (Content-Length), which notes
that:
A server MUST NOT send a Content-Length header field in any
response with a status code of 1xx (Informational) or 204
(No Content).
While it is unlikely that any client will ever be confused by
this behaviour, there is no reason to contravene this part of the
specification.
Modifications:
Removed the line of code setting the header field and changed the
only test that expected it to be there.
Result:
When performing the server portion of HTTP upgrade, the 101
Switching Protocols response will no longer contain a
Content-Length: 0 header field.
