Commit Graph

109 Commits

Author SHA1 Message Date
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
Scott Mitchell
f812180c2d ByteString arrayOffset method
Motivation:
The ByteString class currently assumes the underlying array will be a complete representation of data. This is limiting as it does not allow a subsection of another array to be used. The forces copy operations to take place to compensate for the lack of API support.

Modifications:
- add arrayOffset method to ByteString
- modify all ByteString and AsciiString methods that loop over or index into the underlying array to use this offset
- update all code that uses ByteString.array to ensure it accounts for the offset
- add unit tests to test the implementation respects the offset

Result:
ByteString and AsciiString can represent a sub region of a byte[].
2015-04-24 18:54:01 -07:00
nmittler
70a2608325 Optimizing user-defined stream properties.
Motivation:

Streams currently maintain a hash map of user-defined properties, which has been shown to add significant memory overhead as well as being a performance bottleneck for lookup of frequently used properties.

Modifications:

Modifying the connection/stream to use an array as the storage of user-defined properties, indexed by the class that identifies the index into the array where the property is stored.

Result:

Stream processing performance should be improved.
2015-04-23 12:41:14 -07:00
Scott Mitchell
b426fb1618 Compile error introduced in ee9233d
Motivation:
Commit ee9233d introduced a compile error in microbench.

Modifications:
Fix compile error.

Result:
Code now builds.
2015-04-22 16:23:39 -07:00
Scott Mitchell
541137cc93 HTTP/2 Flow Controller interface updates
Motivation:
Flow control is a required part of the HTTP/2 specification but it is currently structured more like an optional item. It must be accessed through the property map which is time consuming and does not represent its required nature. This access pattern does not give any insight into flow control outside of the codec (or flow controller implementation).

Modifications:
1. Create a read only public interface for LocalFlowState and RemoteFlowState.
2. Add a LocalFlowState localFlowState(); and RemoteFlowState remoteFlowState(); to Http2Stream.

Result:
Flow control is not part of the Http2Stream interface. This clarifies its responsibility and logical relationship to other interfaces. The flow controller no longer must be acquired though a map lookup.
2015-04-20 20:02:02 -07:00
Scott Mitchell
2b8104c852 HTTP/2 Priority Tree Benchmark
Motivation:
There is no benchmark to measure the priority tree implementation performance.

Modifications:
Introduce a new benchmark which will populate the priority tree, and then shuffle parent/child links around.

Result:
A simple benchmark to get a baseline for the HTTP/2 codec's priority tree implementation.
2015-04-17 10:14:13 -07:00
Louis Ryan
f3fb77f4bc Have microbenchmarks produce a deployable artifact. Fix some minor miscellaneous issues.
Motivation:
Allows for running benchmarks from built jars which is useful in development environments that only take released artifacts.

Modifications:
Move benchmarks into 'main' from 'test'
Add @State annotations to benchmarks that are missing them
Fix timing issue grabbing context during channel initialization

Result:
Users can run benchmarks more easily.
2015-04-17 10:04:26 -07:00