Commit Graph

85 Commits

Author SHA1 Message Date
buchgr
c9918de37b http2: Make MAX_HEADER_LIST_SIZE exceeded a stream error when encoding.
Motivation:

The SETTINGS_MAX_HEADER_LIST_SIZE limit, as enforced by the HPACK Encoder, should be a stream error and not apply to the whole connection.

Modifications:

Made the necessary changes for the exception to be of type StreamException.

Result:

A HEADERS frame exceeding the limit, only affects a specific stream.
2016-10-17 09:24:06 -07:00
Scott Mitchell
540c26bb56 HTTP/2 Ensure default settings are correctly enforced and interfaces clarified
Motivation:
The responsibility for retaining the settings values and enforcing the settings constraints is spread out in different areas of the code and may be initialized with different values than the default specified in the RFC. This should not be allowed by default and interfaces which are responsible for maintaining/enforcing settings state should clearly indicate the restrictions that they should only be set by the codec upon receipt of a SETTINGS ACK frame.

Modifications:
- Encoder, Decoder, and the Headers Encoder/Decoder no longer expose public constructors that allow the default settings to be changed.
- Http2HeadersDecoder#maxHeaderSize() exists to provide some bound when headers/continuation frames are being aggregated. However this is roughly the same as SETTINGS_MAX_HEADER_LIST_SIZE (besides the 32 byte octet for each header field) and can be used instead of attempting to keep the two independent values in sync.
- Encoding headers now enforces SETTINGS_MAX_HEADER_LIST_SIZE at the octect level. Previously the header encoder compared the number of header key/value pairs against SETTINGS_MAX_HEADER_LIST_SIZE instead of the number of octets (plus 32 bytes overhead).
- DefaultHttp2ConnectionDecoder#onData calls shouldIgnoreHeadersOrDataFrame but may swallow exceptions from this method. This means a STREAM_RST frame may not be sent when it should for an unknown stream and thus violate the RFC. The exception is no longer swallowed.

Result:
Default settings state is enforced and interfaces related to settings state are clarified.
2016-10-07 13:00:45 -07:00
radai-rosenblatt
15ac6c4a1f Clean-up unused imports
Motivation:

the build doesnt seem to enforce this, so they piled up

Modifications:

removed unused import lines

Result:

less unused imports

Signed-off-by: radai-rosenblatt <radai.rosenblatt@gmail.com>
2016-09-30 09:08:50 +02:00
buchgr
67d3a78123 Reduce bytecode size of PlatformDependent0.equals.
Motivation:

PP0.equals has a bytecode size of 476. This is above the default inlining threshold of OpenJDK.

Modifications:

Slightly change the method to reduce the bytecode size by > 50% to 212 bytes.

Result:

The bytecode size is dramatically reduced, making the method a candidate for inlining.
The relevant code in our application (gRPC) that relies heavily on equals comparisons,
runs some ~10% faster. The Netty JMH benchmark shows no performance regression.

Current 4.1:

PlatformDependentBenchmark.unsafeBytesEqual      10  avgt   20     7.836 ±   0.113  ns/op
PlatformDependentBenchmark.unsafeBytesEqual      50  avgt   20    16.889 ±   4.284  ns/op
PlatformDependentBenchmark.unsafeBytesEqual     100  avgt   20    15.601 ±   0.296  ns/op
PlatformDependentBenchmark.unsafeBytesEqual    1000  avgt   20    95.885 ±   1.992  ns/op
PlatformDependentBenchmark.unsafeBytesEqual   10000  avgt   20   824.429 ±  12.792  ns/op
PlatformDependentBenchmark.unsafeBytesEqual  100000  avgt   20  8907.035 ± 177.844  ns/op

With this change:

PlatformDependentBenchmark.unsafeBytesEqual      10  avgt   20      5.616 ±   0.102  ns/op
PlatformDependentBenchmark.unsafeBytesEqual      50  avgt   20     17.896 ±   0.373  ns/op
PlatformDependentBenchmark.unsafeBytesEqual     100  avgt   20     14.952 ±   0.210  ns/op
PlatformDependentBenchmark.unsafeBytesEqual    1000  avgt   20     94.799 ±   1.604  ns/op
PlatformDependentBenchmark.unsafeBytesEqual   10000  avgt   20    834.996 ±  17.484  ns/op
PlatformDependentBenchmark.unsafeBytesEqual  100000  avgt   20   8757.421 ± 187.555  ns/op
2016-09-09 07:57:41 +02:00
Scott Mitchell
208893aac9 HTTP/2 Hpack Encoder Cleanup
Motivation:
The HTTP/2 HPACK Encoder class has some code which is only used for test purposes. This code can be removed to reduce complexity and member variable count.

Modifications:
- Remove test code and update unit tests
- Other minor cleanup

Result:
Test code is removed from operational code.
2016-08-25 09:08:46 -07:00
Scott Mitchell
21e8d84b79 HTTP/2 Simplify Headers Decode Bounds Checking
Motivation:
The HPACK decoder keeps state so that the decode method can be called multiple times with successive header fragments. This decoder also requires that a method is called to signify the decoding is complete. At this point status is returned to indicate if the max header size has been violated. Netty always accumulates the header fragments into a single buffer before attempting to HPACK decode process and so keeping state and delaying notification that bounds have been exceeded is not necessary.

Modifications:
- HPACK Decoder#decode(..) now must be called with a complete header block
- HPACK will terminate immediately if the maximum header length, or maximum number of headers is exceeded
- Reduce member variables in the HPACK Decoder class because they can now live in the decode(..) method

Result:
HPACK bounds checking is done earlier and less class state is needed.
2016-08-12 17:12:53 -07:00
Scott Mitchell
82b617dfe9 retainSlice() unwrap ByteBuf
Motivation:
retainSlice() currently does not unwrap the ByteBuf when creating the ByteBuf wrapper. This effectivley forms a linked list of ByteBuf when it is only necessary to maintain a reference to the unwrapped ByteBuf.

Modifications:
- retainSlice() and retainDuplicate() variants should only maintain a reference to the unwrapped ByteBuf
- create new unit tests which generally verify the retainSlice() behavior
- Remove unecessary generic arguments from AbstractPooledDerivedByteBuf
- Remove unecessary int length member variable from the unpooled sliced ByteBuf implementation
- Rename the unpooled sliced/derived ByteBuf to include Unpooled in their name to be more consistent with the Pooled variants

Result:
Fixes https://github.com/netty/netty/issues/5582
2016-07-29 11:16:44 -07:00
Scott Mitchell
6af56ffe76 HPACK Encoder headerFields improvements
Motivation:
HPACK Encoder has a data structure which is similar to a previous version of DefaultHeaders. Some of the same improvements can be made.

Motivation:
- Enforce the restriction that the Encoder's headerFields length must be a power of two so we can use masking instead of modulo
- Use AsciiString.hashCode which already has optimizations instead of having yet another hash code algorithm in Encoder

Result:
Fixes https://github.com/netty/netty/issues/5357
2016-06-30 09:00:12 -07:00
Scott Mitchell
a7f7d9c8e0 Remove unsafe char[] access in PlatformDependent
Motivation:
PlatformDependent attempts to use reflection to get the underlying char[] (or byte[]) from String objects. This is fragile as if the String implementation does not utilize the full array, and instead uses a subset of the array, this optimization is invalid. OpenJDK6 and some earlier versions of OpenJDK7 String have the capability to use a subsection of the underlying char[].

Modifications:
- PlatformDependent should not attempt to use the underlying array from String (or other data types) via reflection

Result:
PlatformDependent hash code generation for CharSequence does not depend upon specific JDK implementation details.
2016-06-30 08:58:28 -07:00
Scott Mitchell
70651cc58d HpackUtil.equals performance improvement
Motivation:
PR #5355 modified interfaces to reduce GC related to the HPACK code. However this came with an anticipated performance regression related to HpackUtil.equals due to AsciiString's increase cost of charAt(..). We should mitigate this performance regression.

Modifications:
- Introduce an equals method in PlatformDependent which doesn't leak timing information and use this in HpcakUtil.equals

Result:
Fixes https://github.com/netty/netty/issues/5436
2016-06-27 14:37:39 -07:00
Guido Medina
f0a5ee068f Update dependencies and plugins to latest possible versions.
Motivation:
It is good to have used dependencies and plugins up-to-date to fix any undiscovered bug fixed by the authors.

Modification:
Scanned dependencies and plugins and carefully updated one by one.

Result:
Dependencies and plugins are up-to-date.
2016-06-27 13:35:35 +02:00
Norman Maurer
b4d4c0034d Optimize HPACK usage to align more with Netty types and remove heavy object creations. Related to [#3597]
Motivations:

The HPACK code was not really optimized and written with Netty types in mind. Because of this a lot of garbage was created due heavy object creation.

This was first reported in [#3597] and https://github.com/grpc/grpc-java/issues/1872 .

Modifications:

- Directly use ByteBuf as input and output
- Make use of ByteProcessor where possible
- Use AsciiString as this is the only thing we need for our http2 usage

Result:

Less garbage and better usage of Netty apis.
2016-06-22 14:26:05 +02:00
Norman Maurer
e59d0e9efb Introduce CodecOutputList to reduce overhead of encoder/decoder
Motivation:

99dfc9ea79 introduced some code that will more frequently try to forward messages out of the list of decoded messages to reduce latency and memory footprint. Unfortunally this has the side-effect that RecycleableArrayList.clear() will be called more often and so introduce some overhead as ArrayList will null out the array on each call.

Modifications:

- Introduce a CodecOutputList which allows to not null out the array until we recycle it and also allows to access internal array with extra range checks.
- Add benchmark that add elements to different List implementations and clear them

Result:

Less overhead when decode / encode messages.

Benchmark                                     (elements)   Mode  Cnt         Score        Error  Units
CodecOutputListBenchmark.arrayList                     1  thrpt   20  24853764.609 ± 161582.376  ops/s
CodecOutputListBenchmark.arrayList                     4  thrpt   20  17310636.508 ± 930517.403  ops/s
CodecOutputListBenchmark.codecOutList                  1  thrpt   20  26670751.661 ± 587812.655  ops/s
CodecOutputListBenchmark.codecOutList                  4  thrpt   20  25166421.089 ± 166945.599  ops/s
CodecOutputListBenchmark.recyclableArrayList           1  thrpt   20  24565992.626 ± 210017.290  ops/s
CodecOutputListBenchmark.recyclableArrayList           4  thrpt   20  18477881.775 ± 157003.777  ops/s

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 246.748 sec - in io.netty.handler.codec.CodecOutputListBenchmark
2016-05-20 09:12:07 +02:00
Norman Maurer
68cd670eb9 Remove ChannelHandlerInvoker
Motivation:

We tried to provide the ability for the user to change the semantics of the threading-model by delegate the invoking of the ChannelHandler to the ChannelHandlerInvoker. Unfortunually this not really worked out quite well and resulted in just more complexity and splitting of code that belongs together. We should remove the ChannelHandlerInvoker again and just do the same as in 4.0

Modifications:

Remove ChannelHandlerInvoker again and replace its usage in Http2MultiplexCodec

Result:

Easier code and less bad abstractions.
2016-05-17 11:14:00 +02:00
Scott Mitchell
c5faa142fb KObjectHashMap probeNext improvement
Motivation:
KObjectHashMap.probeNext(..) usually involves 2 conditional statements and 2 aritmatic operations. This can be improved to have 0 conditional statements.

Modifications:
- Use bit masking to avoid conditional statements

Result:
Improved performance for KObjecthashMap.probeNext(..)
2016-05-13 10:04:26 -07:00
Scott Mitchell
d580245afc DefaultHttp2Connection.close Reentrant Modification
Motivation:
The DefaultHttp2Conneciton.close method accounts for active streams being iterated and attempts to avoid reentrant modifications of the underlying stream map by using iterators to remove from the stream map. However there are a few issues:

- While iterating over the stream map we don't prevent iterations over the active stream collection
- Removing a single stream may actually remove > 1 streams due to closed non-leaf streams being preserved in the priority tree which may result in NPE

Preserving closed non-leaf streams in the priority tree is no longer necessary with our current allocation algorithms, and so this feature (and related complexity) can be removed.

Modifications:
- DefaultHttp2Connection.close should prevent others from iterating over the active streams and reentrant modification scenarios which may result from this
- DefaultHttp2Connection should not keep closed stream in the priority tree
  - Remove all associated code in DefaultHttp2RemoteFlowController which accounts for this case including the ReducedState object
  - This includes fixing writability changes which depended on ReducedState
- Update unit tests

Result:
Fixes https://github.com/netty/netty/issues/5198
2016-05-09 14:16:30 -07:00
Norman Maurer
9229ed98e2 [#5088] Add annotation which marks packages/interfaces/classes as unstable
Motivation:

Some codecs should be considered unstable as these are relative new. For this purpose we should introduce an annotation which these codecs should us to be marked as unstable in terms of API.

Modifications:

- Add UnstableApi annotation and use it on codecs that are not stable
- Move http2.hpack to http2.internal.hpack as it is internal.

Result:

Better document unstable APIs.
2016-05-09 15:16:35 +02:00
Xiaoyan Lin
3ad55eb839 Speed up the slow path of FastThreadLocal
Motivation:

The current slow path of FastThreadLocal is much slower than JDK ThreadLocal. See #4418

Modifications:

- Add FastThreadLocalSlowPathBenchmark for the flow path of FastThreadLocal
- Add final to speed up the slow path of FastThreadLocal

Result:

The slow path of FastThreadLocal is improved.
2016-03-23 11:36:16 +01:00
Scott Mitchell
f990f9983d HTTP/2 Don't Flow Control Iniital Headers
Motivation:
Currently the initial headers for every stream is queued in the flow controller. Since the initial header frame may create streams the peer must receive these frames in the order in which they were created, or else this will be a protocol error and the connection will be closed. Tolerating the initial headers being queued would increase the complexity of the WeightedFairQueueByteDistributor and there is benefit of doing so is not clear.

Modifications:
- The initial headers will no longer be queued in the flow controllers

Result:
Fixes https://github.com/netty/netty/issues/4758
2016-02-01 13:37:43 -08:00
Eric Anderson
6dbb610f5b Add ChannelHandlerContext.invoker()
Motivation:

Being able to access the invoker() is useful when adding additional
handlers that should be running in the same thread. Since an application
may be using a threading model unsupported by the default invoker, they
can specify their own. Because of that, in a handler that auto-adds
other handlers:

// This is a good pattern
ctx.pipeline().addBefore(ctx.invoker(), ctx.name(), null, newHandler);
// This will generally work, but prevents using custom invoker.
ctx.pipeline().addBefore(ctx.executor(), ctx.name(), null, newHandler);

That's why I believe in commit 110745b0, for the now-defunct 5.0 branch,
when ChannelHandlerAppender was added the invoker() method was also
necessary.

There is a side-benefit to exposing the invoker: in certain advanced
use-cases using the invoker for a particular handler is useful. Using
the invoker you are able to invoke a _particular_ handler, from possibly
a different thread yet still using standard exception processing.

ChannelHandlerContext does part of that, but is unwieldy when trying to
invoke a particular handler because it invokes the prev or next handler,
not the one the context is for. A workaround is to use the next or prev
context (respectively), but this breaks when the pipeline changes.

This came up during writing the Http2MultiplexCodec which uses a
separate child channel for each http/2 stream and wants to send messages
from the child channel directly to the Http2MultiplexCodec handler that
created it.

Modifications:

Add the invoker() method to ChannelHandlerContext. It was already being
implemented by AbstractChannelHandlerContext. The two other
implementations of ChannelHandlerContext needed minor tweaks.

Result:

Access to the invoker used for a particular handler, for either reusing
for other handlers or for advanced use-cases. Fixes #4738
2016-01-22 14:04:35 +01:00
Xiaoyan Lin
475d901131 Fix errors reported by javadoc
Motivation:

Javadoc reports errors about invalid docs.

Modifications:

Fix some errors reported by javadoc.

Result:

A lot of javadoc errors are fixed by this patch.
2015-12-27 08:36:45 +01:00
zhangduo
f22ad97cf3 Remove PriorityStreamByteDistributor from http2 microbench
Motivation:
PriorityStreamByteDistributor has been removed but NoPriorityByteDistributionBenchmark in microbench still need it and causes compile error

Modifications:
Remove PriorityStreamByteDistributor from NoPriorityByteDistributionBenchmark

Result:
The compile error has been fixed
2015-12-22 09:20:32 +01:00
nmittler
ee56a4a5c6 Fixing broken HTTP/2 benchmark
Motivation:

The `NoPriorityByteDistibbutionBenchmark` was broken with a recent commit.

Modifications:

Fixed the benchmark to use the new HTTP2 handler builder.

Result:

It builds.
2015-12-18 09:52:12 -08:00
Scott Mitchell
904e70a4d4 HTTP/2 Weighted Fair Queue Byte Distributor
Motivation:
PriorityStreamByteDistributor uses a homegrown algorithm which distributes bytes to nodes in the priority tree. PriorityStreamByteDistributor has no concept of goodput which may result in poor utilization of network resources. PriorityStreamByteDistributor also has performance issues related to the tree traversal approach and number of nodes that must be visited. There also exists some more proven algorithms from the resource scheduling domain which PriorityStreamByteDistributor does not employ.

Modifications:
- Introduce a new ByteDistributor which uses elements from weighted fair queue schedulers

Result:
StreamByteDistributor which is sensitive to priority and uses a more familiar distribution concept.
Fixes https://github.com/netty/netty/issues/4462
2015-12-17 11:17:02 -08:00
Trustin Lee
2202e8f967 Revamp the Http2ConnectionHandler builder API
Related: #4572

Motivation:

- A user might want to extend Http2ConnectionHandler and define his/her
  own static inner Builder class that extends
  Http2ConnectionHandler.BuilderBase. This introduces potential
  confusion because there's already Http2ConnectionHandler.Builder. Your
  IDE will warn about this name duplication as well.
- BuilderBase exposes all setters with public modifier. A user's Builder
  might not want to expose them to enforce it to certain configuration.
  There's no way to hide them because it's public already and they are
  final.
- BuilderBase.build(Http2ConnectionDecoder, Http2ConnectionEncoder)
  ignores most properties exposed by BuilderBase, such as
  validateHeaders, frameLogger and encoderEnforceMaxConcurrentStreams.
  If any build() method ignores the properties exposed by the builder,
  there's something wrong.
- A user's Builder that extends BuilderBase might want to require more
  parameters in build(). There's no way to do that cleanly because
  build() is public and final already.

Modifications:

- Make BuilderBase and Builder top-level so that there's no duplicate
  name issue anymore.
  - Add AbstractHttp2ConnectionHandlerBuilder
  - Add Http2ConnectionHandlerBuilder
  - Add HttpToHttp2ConnectionHandlerBuilder
- Make all builder methods in AbstractHttp2ConnectionHandlerBuilder
  protected so that a subclass can choose which methods to expose
- Provide only a single build() method
  - Add connection() and codec() so that a user can still specify
    Http2Connection or Http2Connection(En|De)coder explicitly
  - Implement proper state validation mechanism so that it is prevented
    to invoke conflicting setters

Result:

Less confusing yet flexible builder API
2015-12-17 14:08:13 +09:00
Scott Mitchell
641505a5d2 DefaultChannelConfig maxMessagesPerRead default not always set
Motivation:
ChannelMetadata has a field minMaxMessagesPerRead which can be confusing. There are also some cases where static instances are used and the default value for channel type is not being applied.

Modifications:
- use a default value which is set unconditionally to simplify
- make sure static instances of MaxMessagesRecvByteBufAllocator are not used if the intention is that the default maxMessagesPerRead should be derived from the channel type.

Result:
Less confusing interfaces in ChannelMetadata and ChannelConfig. Default maxMessagesPerRead is correctly applied.
2015-11-25 15:14:07 -08:00
Scott Mitchell
49cd00da1c Backport of benchmark broke build
Motivation:
2a2059d976 was backported from master, and included an overriden method which does not exist in 4.1.

Modifications:
- Remove the invoker method from NoPriorityByteDistributionBenchmark

Result:
No more build error
2015-11-20 15:03:50 -08:00
nmittler
2a2059d976 Adding UniformStreamByteDistributor
Motivation:

The current priority algorithm can yield poor per-stream goodput when either the number of streams is high or the connection window is small. When all priorities are the same (i.e. priority is disabled), we should be able to do better.

Modifications:

Added a new UniformStreamByteDistributor that ignores priority entirely and manages a queue of streams.  Each stream is allocated a minimum of 1KiB on each iteration.

Result:

Improved goodput when priority is not used.
2015-11-19 16:49:12 -08:00
nmittler
8accc52b03 Forking Twitter's hpack
Motivation:

The twitter hpack project does not have the support that it used to have.  See discussion here: https://github.com/netty/netty/issues/4403.

Modifications:

Created a new module in Netty and copied the latest from twitter hpack master.

Result:

Netty no longer depends on twitter hpack.
2015-11-14 10:13:32 -08:00
Scott Mitchell
b4b791353d AsciiString optimized hashCode
Motivation:
The AsciiString.hashCode() method can be optimized. This method is frequently used while to build the DefaultHeaders data structure.

Modification:
- Add a PlatformDependent hashCode algorithm which utilizes UNSAFE if available

Result:
AsciiString hashCode is faster.
2015-11-10 10:28:31 -08:00
Louis Ryan
6e108cb96a Improve the performance of copying header sets when hashing and name validation are equivalent.
Motivation:
Headers and groups of headers are frequently copied and the current mechanism is slower than it needs to be.

Modifications:
Skip name validation and hash computation when they are not necessary.
Fix emergent bug in CombinedHttpHeaders identified with better testing
Fix memory leak in DefaultHttp2Headers when clearing
Added benchmarks

Result:
Faster header copying and some collateral bug fixes
2015-11-07 08:53:10 -08:00
nmittler
6504d52b94 Add HTTP/2 local flow control option for auto refill
Motivation:

For many HTTP/2 applications (such as gRPC) it is necessary to autorefill the connection window in order to prevent application-level deadlocking.

Consider an application with 2 streams, A and B.  A receives a stream of messages and the application pops off one message at a time and makes a request on stream B. However, if receiving of data on A has caused the connection window to collapse, B will not be able to receive any data and the application will deadlock.  The only way (currently) to get around this is 1) use multiple connections, or 2) manually refill the connection window.  Both are undesirable and could needlessly complicate the application code.

Modifications:

Add a configuration option to DefaultHttp2LocalFlowController, allowing it to autorefill the connection window.

Result:

Applications can configure HTTP/2 to avoid inter-stream deadlocking.
2015-11-05 15:47:10 -08:00
Norman Maurer
1b2e43e70c Correctly construct Executor in microbenchmarks.
Motivation:

We should allow our custom Executor to shutdown quickly.

Modifications:

Call super constructor which correct arguments.

Result:

Custom Executor can be shutdown quickly.
2015-11-03 09:46:05 +01:00
Scott Mitchell
19658e9cd8 HTTP/2 Headers Type Updates
Motivation:
The HTTP/2 RFC (https://tools.ietf.org/html/rfc7540#section-8.1.2) indicates that header names consist of ASCII characters. We currently use ByteString to represent HTTP/2 header names. The HTTP/2 RFC (https://tools.ietf.org/html/rfc7540#section-10.3) also eludes to header values inheriting the same validity characteristics as HTTP/1.x. Using AsciiString for the value type of HTTP/2 headers would allow for re-use of predefined HTTP/1.x values, and make comparisons more intuitive. The Headers<T> interface could also be expanded to allow for easier use of header types which do not have the same Key and Value type.

Motivation:
- Change Headers<T> to Headers<K, V>
- Change Http2Headers<ByteString> to Http2Headers<CharSequence, CharSequence>
- Remove ByteString. Having AsciiString extend ByteString complicates equality comparisons when the hash code algorithm is no longer shared.

Result:
Http2Header types are more representative of the HTTP/2 RFC, and relationship between HTTP/2 header name/values more directly relates to HTTP/1.x header names/values.
2015-10-30 15:29:44 -07:00
buchgr
c9364616c8 Fix performance regression in FastThreadLocal microbenchmark. Fixes #4402
Motivation:

As reported in #4402, the FastThreadLocalBenchmark shows that the JDK ThreadLocal
is actually faster than Netty's custom thread local implementation.

I was looking forward to doing some deep digging, but got disappointed :(.

Modifications:

The microbenchmark was not using FastThreadLocalThreads and would thus always hit the slow path.
I updated the JMH command line flags, so that FastThreadLocalThreads would be used.

Result:

FastThreadLocalBenchmark shows FastThreadLocal to be faster than JDK's ThreadLocal implementation,
by about 56% in this particular benchmark. Run on OSX El Capitan with OpenJDK 1.8u60.

Benchmark                                    Mode  Cnt      Score      Error  Units
FastThreadLocalBenchmark.fastThreadLocal    thrpt   20  55452.027 ±  725.713  ops/s
FastThreadLocalBenchmark.jdkThreadLocalGet  thrpt   20  35481.888 ± 1471.647  ops/s
2015-10-29 21:40:13 +01:00
Norman Maurer
2e36ac4594 Add benchmark for HeapByteBuf implementations.
Motivation:

To prove one implementation is faster as the other we should have a benchmark.

Modifications:

Add benchmark which benchmarks the unsafe and non-unsafe implementation of HeapByteBuf.

Result:

Able to compare speed of implementations easily.
2015-10-29 19:38:52 +01:00
Norman Maurer
a47685b243 Use bitwise operation when sampling for resource leak detection.
Motivation:

Modulo operations are slow, we can use bitwise operation to detect if resource leak detection must be done while sampling.

Modifications:

- Ensure the interval is a power of two
- Use bitwise operation for sampling
- Add benchmark.

Result:

Faster sampling.
2015-10-29 19:18:44 +01:00
Norman Maurer
4c287d4e27 Added SlicedAbstractByteBuf that can provide fast-path for _get* and _set* methods
Motivation:

SlicedByteBuf can be used for any ByteBuf implementations and so can not do any optimizations that could be done
when AbstractByteBuf is sliced.

Modifications:

- Add SlicedAbstractByteBuf that can eliminate range and reference count checks for _get* and _set* methods.

Result:

Faster SlicedByteBuf implementations for AbstractByteBuf sub-classes.
2015-10-16 09:12:20 +02:00
Norman Maurer
2aef4a504f Minimize object allocation when calling AbstractByteBuf.toString(..., Charset)
Motivation:

Calling AbstractByteBuf.toString(..., Charset) is used quite frequently by users but produce a lot of GC.

Modification:

- Use a FastThreadLocal to store the CharBuffer that are needed for decoding.
- Use internalNioBuffer(...) when possible

Result:

Less object creation / Less GC
2015-10-15 17:51:57 +02:00
Norman Maurer
9697afc106 Allow to disable reference count checks on every access of the ByteBuf
Motiviation:

Checking reference count on every access on a ByteBuf can have some big performance overhead depending on how the access pattern is. If the user is sure that there are no reference count errors on his side it should be possible to disable the check and so gain the max performance.

Modification:

- Add io.netty.buffer.bytebuf.checkAccessible system property which allows to disable the checks. Enabled by default.
- Add microbenchmark

Result:

Increased performance for operations on the ByteBuf.
2015-10-15 10:21:16 +02:00
Scott Mitchell
d4680c55d8 AsciiString contains utility methods
Motivation:
When dealing with case insensitive headers it can be useful to have a case insensitive contains method for CharSequence.

Modifications:
- Add containsCaseInsensative to AsciiString

Result:
More expressive utility method for case insensitive CharSequence.
2015-10-02 12:50:11 -07:00
Scott Mitchell
284e3702d8 Http2ConnectionHandler Builder instead of constructors
Motivation:
Using the builder pattern for Http2ConnectionHandler (and subclasses) would be advantageous for the following reasons:
1. Provides the consistent construction afforded by the builder pattern for 'optional' arguments. Users can specify these options 1 time in the builder and then re-use the builder after this.
2. Enforces that the Http2ConnectionHandler's internals (decoder Http2FrameListener) are initialized after construction.

Modifications:
- Add an extensible builder which can be used to build Http2ConnectionHandler objects
- Update classes which inherit from Http2ConnectionHandler

Result:
It is easier to specify options and construct Http2ConnectionHandler objects.
2015-10-01 13:51:03 -07:00
Scott Mitchell
1485a87e25 Http2ConnectionHandler and Http2FrameListener cyclic dependency
Motivation:
It is often the case that implementations of Http2FrameListener will want to send responses when data is read. The Http2FrameListener needs access to the Http2ConnectionHandler (or the encoder contained within) to be able to send responses. However the Http2ConnectionHandler requires a Http2FrameListener instance to be passed in during construction time. This creates a cyclic dependency which can make it difficult to cleanly accomplish this relationship.

Modifications:
- Add Http2ConnectionDecoder.frameListener(..) method to set the frame listener. This will allow the listener to be set after construction.

Result:
Classes which inherit from Http2ConnectionHandler can more cleanly set the Http2FrameListener.
2015-09-30 15:41:15 -07:00
Scott Mitchell
0e9545e94d Http2RemoteFlowController stream writibility listener
Motivation:
For implementations that want to manage flow control down to the stream level it is useful to be notified when stream writability changes.

Modifications:
- Add writabilityChanged to Http2RemoteFlowController.Listener
- Add isWritable to Http2RemoteFlowController

Result:
The Http2RemoteFlowController provides notification when writability of a stream changes.
2015-09-28 13:47:24 -07:00
Scott Mitchell
ba6ce5449e Headers Performance Boost and Interface Simplification
Motivation:
A degradation in performance has been observed from the 4.0 branch as documented in https://github.com/netty/netty/issues/3962.

Modifications:
- Simplify Headers class hierarchy.
- Restore the DefaultHeaders to be based upon DefaultHttpHeaders from 4.0.
- Make various other modifications that are causing hot spots.

Result:
Performance is now on par with 4.0.
2015-08-17 08:50:11 -07:00
Jakob Buchgraber
6fd0a0c55f Faster and more memory efficient headers for HTTP, HTTP/2, STOMP and SPYD. Fixes #3600
Motivation:

We noticed that the headers implementation in Netty for HTTP/2 uses quite a lot of memory
and that also at least the performance of randomly accessing a header is quite poor. The main
concern however was memory usage, as profiling has shown that a DefaultHttp2Headers
not only use a lot of memory it also wastes a lot due to the underlying hashmaps having
to be resized potentially several times as new headers are being inserted.

This is tracked as issue #3600.

Modifications:
We redesigned the DefaultHeaders to simply take a Map object in its constructor and
reimplemented the class using only the Map primitives. That way the implementation
is very concise and hopefully easy to understand and it allows each concrete headers
implementation to provide its own map or to even use a different headers implementation
for processing requests and writing responses i.e. incoming headers need to provide
fast random access while outgoing headers need fast insertion and fast iteration. The
new implementation can support this with hardly any code changes. It also comes
with the advantage that if the Netty project decides to add a third party collections library
as a dependency, one can simply plug in one of those very fast and memory efficient map
implementations and get faster and smaller headers for free.

For now, we are using the JDK's TreeMap for HTTP and HTTP/2 default headers.

Result:

- Significantly fewer lines of code in the implementation. While the total commit is still
  roughly 400 lines less, the actual implementation is a lot less. I just added some more
  tests and microbenchmarks.

- Overall performance is up. The current implementation should be significantly faster
  for insertion and retrieval. However, it is slower when it comes to iteration. There is simply
  no way a TreeMap can have the same iteration performance as a linked list (as used in the
  current headers implementation). That's totally fine though, because when looking at the
  benchmark results @ejona86 pointed out that the performance of the headers is completely
  dominated by insertion, that is insertion is so significantly faster in the new implementation
  that it does make up for several times the iteration speed. You can't iterate what you haven't
  inserted. I am demonstrating that in this spreadsheet [1]. (Actually, iteration performance is
  only down for HTTP, it's significantly improved for HTTP/2).

- Memory is down. The implementation with TreeMap uses on avg ~30% less memory. It also does not
  produce any garbage while being resized. In load tests for GRPC we have seen a memory reduction
  of up to 1.2KB per RPC. I summarized the memory improvements in this spreadsheet [1]. The data
  was generated by [2] using JOL.

- While it was my original intend to only improve the memory usage for HTTP/2, it should be similarly
  improved for HTTP, SPDY and STOMP as they all share a common implementation.

[1] https://docs.google.com/spreadsheets/d/1ck3RQklyzEcCLlyJoqDXPCWRGVUuS-ArZf0etSXLVDQ/edit#gid=0
[2] https://gist.github.com/buchgr/4458a8bdb51dd58c82b4
2015-08-04 17:12:24 -07:00
Scott Mitchell
a7713069a1 HttpObjectDecoder performance improvements
Motivation:
The HttpObjectDecoder is on the hot code path for the http codec. There are a few hot methods which can be modified to improve performance.

Modifications:
- Modify AppendableCharSequence to provide unsafe methods which don't need to re-check bounds for every call.
- Update HttpObjectDecoder methods to take advantage of new AppendableCharSequence methods.

Result:
Peformance boost for decoding http objects.
2015-07-29 23:26:26 -07:00
Scott Mitchell
9747ffe5fc HTTP/2 Flow Controller should use Channel.isWritable()
Motivation:
See #3783

Modifications:
- The DefaultHttp2RemoteFlowController should use Channel.isWritable() before attempting to do any write operations.
- The Flow controller methods should no longer take ChannelHandlerContext. The concept of flow control is tied to a connection and we do not support 1 flow controller keeping track of multiple ChannelHandlerContext.

Result:
Writes are delayed until isWritable() is true. Flow controller interface methods are more clear as to ChannelHandlerContext restrictions.
2015-07-16 14:38:48 -07:00
Louis Ryan
05ce33f5ca Make the flow-controllers write fewer, fatter frames to improve throughput.
Motivation:

Coalescing many small writes into a larger DATA frame reduces framing overheads on the wire and reduces the number of calls to Http2FrameListeners on the remote side.
Delaying the write of WINDOW_UPDATE until flush allows for more consumed bytes to be returned as the aggregate of consumed bytes is returned and not the amount consumed when the threshold was crossed.

Modifications:
- Remote flow controller no longer immediately writes bytes when a flow-controlled payload is enqueued. Sequential data payloads are now merged into a single CompositeByteBuf which are written when 'writePendingBytes' is called.
- Listener added to remote flow-controller which observes written bytes per stream.
- Local flow-controller no longer immediately writes WINDOW_UPDATE when the ratio threshold is crossed. Now an explicit call to 'writeWindowUpdates' triggers the WINDOW_UPDATE for all streams who's ratio is exceeded at that time. This results in
  fewer window updates being sent and more bytes being returned.
- Http2ConnectionHandler.flush triggers 'writeWindowUpdates' on the local flow-controller followed by 'writePendingBytes' on the remote flow-controller so WINDOW_UPDATES preceed DATA frames on the wire.

Result:
- Better throughput for writing many small DATA chunks followed by a flush, saving 9-bytes per coalesced frame.
- Fewer WINDOW_UPDATES being written and more flow-control bytes returned to remote side more quickly, thereby improving throughput.
2015-06-19 15:20:31 -07:00
Louis Ryan
a3cea186ce Have Http2LocalFlowController.consumeBytes indicate whether a WINDOW_UPDATE was written 2015-05-04 13:22:18 -07:00