Test case
```java
@Test
    public void freesPingFrames() {
        ByteBuf content = UnpooledByteBufAllocator.DEFAULT.buffer(8).writeLong(0);
        DefaultHttp2PingFrame frame = new DefaultHttp2PingFrame(content);
        assertEquals(1, content.refCnt());
        codec.onHttp2Frame(frame);
        assertEquals(0, content.refCnt());
    }
```
 posted [here](https://github.com/bryce-anderson/netty/commit/37cdcd4defa853e5b9883c9bbea60e91a72ac5c6#diff-da759abb652d5db65698f9baf72b9ed2) results in
```
java.lang.AssertionError: 
Expected :0
Actual   :1

io.netty.handler.codec.http2.Http2MultiplexCodecTest.freesPingFrames(Http2MultiplexCodecTest.java:134)
``` If I can get someone to sanity check my results, this the fix is trivial and I'm happy to do it. Your assessment seems correct to me. It has been a while but I think the though process at the time was "we aren't sure if the user will need to care about ping (or ping ack) yet so lets drop it". However we retain the `ByteBuf` so that approach is inconsistent. My vote would be to propagate this through the parent channel's pipeline (as a channel read) so the user has visibility into it (instead of just releasing it as suggested in your unit test above). If the user doesn't handle it then it will automatically be released at the tail of the pipeline and a message will be logged (just like usual). @ejona86 @normanmaurer @carl-mastrangelo - WDYT? Note that users can also intercept these messages via wrapping the `FrameListener`, although that's a bit intricate to setup. `codec-http2` currently has two flavors of APIs:
- `Http2ConnectionHandler` and `FrameListener` - the initial API, lots of hours/usage on this code, low object allocation, not canonical Netty design (extensibility via the channel pipeline is challenging)
- `Http2FrameCodec` and `Http2MultiplexCodec` - new API design which is more canonical Netty, more object allocation, not as much hours/usage (thus "simple" bugs like this).

We try to minimize how much of the `FrameListener` API is exposed from the `Http2MultiplexCodec` and ideally its usage of the `FrameListener` is an implementation detail. I think what @Scottmitch proposes makes sense here. @bryce-anderson please go ahead and implement it or let us know if you have no time and we should do once we have cycles.  PR submitted. https://github.com/netty/netty/pull/7612

I suppose having a downstream handler gives the user a vector for sending and receiving pings so propagating unhandled frames downstream seems right to me too unless you have plans to offer a first class API for pings. > unless you have plans to offer a first class API for pings.

The API would be object propagation through the pipeline (just like most other Netty codecs) so I think we are good here. It seems there's a general problem with Http2MultiplexCodec: it should either release or propagate unknown types. That's what #7612 does. So I'm good with that PR.

However, I don't think we actually want to propagate PINGs, or at least in that way.

I'd suggest two options:
1. Don't propagate inbound PINGs. Instead, let an outbound PING have a Future that will be completed when the PING ACK arrives. The payload of PING wouldn't be exposed at all. (If we separated Http2MultiplexCodec from Http2FrameCodec we could propagate the PING within that small area, but that doesn't exist today. This is why PING existed during my earlier h2childchan PRs.)
2. Use a userEvent. I don't like propagating the read because the logging isn't really acceptable. As a user you're forced to handle it. Yes, it will be "handled" without you doing anything, but the logging just tells you "you're doing it wrong." That's the approach I was taking for the child chan itself; everything optional is a user event or has a trigger to enable.

For (2), if we're going to expose the payload, let's use a simple long or byte[] instead of ByteBuf. The size of the payload is fixed and really small. There's really no gain by using ByteBuf and the refcounting complicates things. This is the same approach I want to make for Http2GoAwayFrame. It is sort of "neither here nor there" for how we handle PING, though. > Don't propagate inbound PINGs. Instead, let an outbound PING have a Future that will be completed when the PING ACK arrives.

This is not consistent with Netty APIs which typically don't cater to request/response based APIs and instead rely upon the pipeline to propagate data. Since one of the primary goals of the child channel API is to be consistent/canonical with Netty I would suggest we stick with the pipeline approach. Higher layers can build a promise based notification system if that is desired.

> Use a userEvent.

The primary motivation for these seems to be "the logging at the tail of the pipeline maybe noisy". If this is the case I would prefer to stick with the "channelRead" because it seems more semantically correct. PING is a data event defined by the protocol, where as userEvents are primarily to propagate control messages between handlers in the pipeline. We can always [override the pipeline behavior](https://github.com/netty/netty/blob/4.1/transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java#L1194) to avoid logging in scenarios that are "safe" to ignore.

> For (2), if we're going to expose the payload, let's use a simple long or byte[] instead of ByteBuf. 

My main hesitation here is copying when it may otherwise not be necessary. Agreed that refcounting increases complexity, but that is not newly introduced here and is wide spread in Netty. I'm not strongly opposed but using ByteBuf is common practice in Netty and can avoid memory copies when folks may not otherwise even care about the payload content, or can immediately discard (e.g. release) it. > This is not consistent with Netty APIs which typically don't cater to request/response based APIs and instead rely upon the pipeline to propagate data.

There was another reason I was doing it: to manage allocating of PING ids. The payload is frequently an ID to keep easier track of what the ACKs mean. Coordinating the allocation is a bit of a problem since there are multiple handlers (including the HTTP/2 code itself) that may need to send them. Normally in Netty there's no need for coordination.

> We can always override the pipeline behavior to avoid logging in scenarios that are "safe" to ignore.

Wait... it's a logger.debug... that's completely fine. And it's been that way... "forever". Now I wonder what in the world I was seeing...

Luckily I don't think that changes my design of the child channels.

> My main hesitation here is copying when it may otherwise not be necessary.

Copying _8_ bytes? The ByteBuf pointer chasing and vtable indirection will be much more costly than that. And a pointer is 8 bytes, so we're _already_ copying the equivalent amount of data. And a pointer assignment is also more expensive in Java to coordinate with the GC. The ByteBuf will also need read and write indexes and a capacity and ref counting and...

The copying could be a bigger concern for GOAWAY, but the messages tend to be short. (I've not seen one larger than, say, 16 bytes?) But the GOAWAY case is also the one that benefits the most, in that [we're duplicating a DefaultHttp2GoAwayFrame and a ByteBuf for each child channel](https://github.com/netty/netty/blob/911b2ac/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java#L326). That's (8+4+4)+(8+4+4+4+4+4) = 44 bytes (assuming a DuplicatedByteBuf). If we used a byte[], we could actually share the same DefaultHttp2GoAwayFrame across all child channels, because there's no longer the readerIndex.

To me, the argument for keeping it as a ByteBuf is that it is convenient, because people are familiar with working with them. Agreed `ByteBuf` currently has a high constant overhead and is bloated for small payloads (which is exacerbated by duplication/wrapping). Good point about the payload size. Even if its a few hundred bytes (GOAWAY debug information) it is likely a rare occurrence and may not be worth the extra complexity. I think the main selling point would be consistency, but I agree it doesn't seem worth it. @normanmaurer - WDYT?

> we could actually share the same DefaultHttp2GoAwayFrame across all child channels, because there's no longer the readerIndex.

Sharing should be possible either way, no? Just with `ByteBuf` it requires reference count management and may not incur framing overhead (copy from byte[] to the frame to write). > Sharing should be possible either way, no?

No... :''( . If one child channel reads the ByteBuf, then the readerIndex will be changed for all the child channels. So only the first reader gets to see what's inside, unless all readers make sure to avoid updating the readerIndex. >  If one child channel reads the ByteBuf

So there are 2 concerns:

- reference counting. we should be able to manage via `retain`/`release`.
- reader/writer indexes. we should be able to use `duplicate()`/`slice()`.

Does this make sense? This is the design of the `ByteBuf` API and not necessarily new here. Not saying its what we want todo, but its an option IIUC. lets continue discussion in https://github.com/netty/netty/issues/7629
btw, do you need to free this content? Do you mean for the test, or for the `Http2MultiplexedCodec`? It doesn't look like it's released. It should be. That's why the CI test fails with "Build failure on specific text in build log: Resource leak detected". IIUC we need a `decodedFrame.release();` after the assert. Should be fixed now. you need to call `receivedPing.release()` as well to ensure we not leak. This way the CI will also pass. I think you might have been looking at an outdated PR: it's released on line 181 and tests are green. yep seems so :D all good...
Http2MultiplexCodec leaks ping payloads
### Expected behavior

The payload of a PingFrame would be released or passed somewhere into the application for consumption.

### Actual behavior

It appears that `Http2PingFrame`s are dropped on the floor in the [`Http2MultiplexCodec.onHttp2Frame`](https://github.com/netty/netty/blob/4.1/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java#L219) method.

### Steps to reproduce

Start HTTP/2 server and send it ping frames with advanced leak detection yields logs as follows:
```
2018-01-22 22:46:25,178 ERR i.n.u.ResourceLeakDetector |  LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records: 16
#16:
	io.netty.util.ReferenceCountUtil.release(ReferenceCountUtil.java:84)
	io.netty.util.ReferenceCountUtil.safeRelease(ReferenceCountUtil.java:109)
	io.netty.channel.ChannelOutboundBuffer.remove(ChannelOutboundBuffer.java:256)
	io.netty.channel.ChannelOutboundBuffer.removeBytes(ChannelOutboundBuffer.java:337)
	io.netty.channel.epoll.AbstractEpollStreamChannel.writeBytesMultiple(AbstractEpollStreamChannel.java:302)
	io.netty.channel.epoll.AbstractEpollStreamChannel.doWriteMultiple(AbstractEpollStreamChannel.java:505)
	io.netty.channel.epoll.AbstractEpollStreamChannel.doWrite(AbstractEpollStreamChannel.java:442)
	io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:934)
	io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe.flush0(AbstractEpollChannel.java:543)
	io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:901)
	io.netty.channel.DefaultChannelPipeline$HeadContext.flush(DefaultChannelPipeline.java:1321)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768)
	io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749)
	io.netty.channel.ChannelDuplexHandler.flush(ChannelDuplexHandler.java:117)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768)
	io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749)
	io.netty.handler.codec.http2.Http2ConnectionHandler.flush(Http2ConnectionHandler.java:201)
	io.netty.handler.codec.http2.Http2MultiplexCodec.flush(Http2MultiplexCodec.java:373)
	io.netty.handler.codec.http2.Http2MultiplexCodec.flush0(Http2MultiplexCodec.java:378)
	io.netty.handler.codec.http2.Http2MultiplexCodec.onChannelReadComplete(Http2MultiplexCodec.java:366)
	io.netty.handler.codec.http2.Http2MultiplexCodec.channelReadComplete(Http2MultiplexCodec.java:340)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:398)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:380)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelReadComplete(AbstractChannelHandlerContext.java:373)
	io.netty.channel.ChannelInboundHandlerAdapter.channelReadComplete(ChannelInboundHandlerAdapter.java:97)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:398)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:380)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelReadComplete(AbstractChannelHandlerContext.java:373)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelReadComplete(DefaultChannelPipeline.java:1364)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:398)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:380)
	io.netty.channel.DefaultChannelPipeline.fireChannelReadComplete(DefaultChannelPipeline.java:941)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:817)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#15:
	io.netty.buffer.AdvancedLeakAwareByteBuf.nioBufferCount(AdvancedLeakAwareByteBuf.java:702)
	io.netty.channel.unix.IovArray.add(IovArray.java:79)
	io.netty.channel.unix.IovArray.processMessage(IovArray.java:209)
	io.netty.channel.ChannelOutboundBuffer.forEachFlushedMessage(ChannelOutboundBuffer.java:738)
	io.netty.channel.epoll.AbstractEpollStreamChannel.doWriteMultiple(AbstractEpollStreamChannel.java:500)
	io.netty.channel.epoll.AbstractEpollStreamChannel.doWrite(AbstractEpollStreamChannel.java:442)
	io.netty.channel.AbstractChannel$AbstractUnsafe.flush0(AbstractChannel.java:934)
	io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe.flush0(AbstractEpollChannel.java:543)
	io.netty.channel.AbstractChannel$AbstractUnsafe.flush(AbstractChannel.java:901)
	io.netty.channel.DefaultChannelPipeline$HeadContext.flush(DefaultChannelPipeline.java:1321)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768)
	io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749)
	io.netty.channel.ChannelDuplexHandler.flush(ChannelDuplexHandler.java:117)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush0(AbstractChannelHandlerContext.java:776)
	io.netty.channel.AbstractChannelHandlerContext.invokeFlush(AbstractChannelHandlerContext.java:768)
	io.netty.channel.AbstractChannelHandlerContext.flush(AbstractChannelHandlerContext.java:749)
	io.netty.handler.codec.http2.Http2ConnectionHandler.flush(Http2ConnectionHandler.java:201)
	io.netty.handler.codec.http2.Http2MultiplexCodec.flush(Http2MultiplexCodec.java:373)
	io.netty.handler.codec.http2.Http2MultiplexCodec.flush0(Http2MultiplexCodec.java:378)
	io.netty.handler.codec.http2.Http2MultiplexCodec.onChannelReadComplete(Http2MultiplexCodec.java:366)
	io.netty.handler.codec.http2.Http2MultiplexCodec.channelReadComplete(Http2MultiplexCodec.java:340)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:398)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:380)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelReadComplete(AbstractChannelHandlerContext.java:373)
	io.netty.channel.ChannelInboundHandlerAdapter.channelReadComplete(ChannelInboundHandlerAdapter.java:97)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:398)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:380)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelReadComplete(AbstractChannelHandlerContext.java:373)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelReadComplete(DefaultChannelPipeline.java:1364)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:398)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:380)
	io.netty.channel.DefaultChannelPipeline.fireChannelReadComplete(DefaultChannelPipeline.java:941)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:817)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#14:
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:273)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#13:
	io.netty.buffer.DefaultByteBufHolder.retain(DefaultByteBufHolder.java:93)
	io.netty.handler.codec.http2.DefaultHttp2PingFrame.retain(DefaultHttp2PingFrame.java:76)
	io.netty.handler.codec.http2.Http2FrameCodec$FrameListener.onPingRead(Http2FrameCodec.java:488)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onPingRead(DefaultHttp2ConnectionDecoder.java:432)
	io.netty.handler.codec.http2.Http2InboundFrameLogger$1.onPingRead(Http2InboundFrameLogger.java:99)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readPingFrame(DefaultHttp2FrameReader.java:583)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:269)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#12:
	Hint: 'DefaultChannelPipeline$HeadContext#0' will handle the message from this point.
	io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
	io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:810)
	io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:723)
	io.netty.channel.ChannelDuplexHandler.write(ChannelDuplexHandler.java:106)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.write(ChannelStatsHandler.scala:96)
	io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:738)
	io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:730)
	io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:816)
	io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:723)
	io.netty.handler.codec.http2.DefaultHttp2FrameWriter.writePing(DefaultHttp2FrameWriter.java:281)
	io.netty.handler.codec.http2.Http2OutboundFrameLogger.writePing(Http2OutboundFrameLogger.java:99)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writePing(DefaultHttp2ConnectionEncoder.java:269)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onPingRead(DefaultHttp2ConnectionDecoder.java:430)
	io.netty.handler.codec.http2.Http2InboundFrameLogger$1.onPingRead(Http2InboundFrameLogger.java:99)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readPingFrame(DefaultHttp2FrameReader.java:583)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:269)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#11:
	Hint: 'channelStats' will handle the message from this point.
	io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
	io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:810)
	io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:723)
	io.netty.handler.codec.http2.DefaultHttp2FrameWriter.writePing(DefaultHttp2FrameWriter.java:281)
	io.netty.handler.codec.http2.Http2OutboundFrameLogger.writePing(Http2OutboundFrameLogger.java:99)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writePing(DefaultHttp2ConnectionEncoder.java:269)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onPingRead(DefaultHttp2ConnectionDecoder.java:430)
	io.netty.handler.codec.http2.Http2InboundFrameLogger$1.onPingRead(Http2InboundFrameLogger.java:99)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readPingFrame(DefaultHttp2FrameReader.java:583)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:269)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#10:
	io.netty.buffer.AdvancedLeakAwareByteBuf.retainedSlice(AdvancedLeakAwareByteBuf.java:84)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onPingRead(DefaultHttp2ConnectionDecoder.java:430)
	io.netty.handler.codec.http2.Http2InboundFrameLogger$1.onPingRead(Http2InboundFrameLogger.java:99)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readPingFrame(DefaultHttp2FrameReader.java:583)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:269)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#9:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readSlice(AdvancedLeakAwareByteBuf.java:114)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readPingFrame(DefaultHttp2FrameReader.java:579)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:269)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#8:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readSlice(AdvancedLeakAwareByteBuf.java:114)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:243)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#7:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readInt(AdvancedLeakAwareByteBuf.java:432)
	io.netty.handler.codec.http2.Http2CodecUtil.readUnsignedInt(Http2CodecUtil.java:210)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processHeaderState(DefaultHttp2FrameReader.java:192)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:148)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#6:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readUnsignedByte(AdvancedLeakAwareByteBuf.java:402)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processHeaderState(DefaultHttp2FrameReader.java:191)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:148)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#5:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readByte(AdvancedLeakAwareByteBuf.java:396)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processHeaderState(DefaultHttp2FrameReader.java:190)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:148)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#4:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readUnsignedMedium(AdvancedLeakAwareByteBuf.java:426)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.processHeaderState(DefaultHttp2FrameReader.java:185)
	io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:148)
	io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
	io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:118)
	io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:383)
	io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:443)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:489)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:428)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#3:
	Hint: 'UpgradeMultiplexCodecBuilder$$anon$1#0' will handle the message from this point.
	io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
	com.twitter.finagle.netty4.channel.ChannelStatsHandler.channelRead(ChannelStatsHandler.scala:108)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#2:
	Hint: 'channelStats' will handle the message from this point.
	io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
#1:
	Hint: 'DefaultChannelPipeline$HeadContext#0' will handle the message from this point.
	io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:797)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
Created at:
	io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:331)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:181)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:172)
	io.netty.buffer.AbstractByteBufAllocator.ioBuffer(AbstractByteBufAllocator.java:133)
	io.netty.channel.DefaultMaxMessagesRecvByteBufAllocator$MaxMessageHandle.allocate(DefaultMaxMessagesRecvByteBufAllocator.java:80)
	io.netty.channel.epoll.EpollRecvByteAllocatorHandle.allocate(EpollRecvByteAllocatorHandle.java:71)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:786)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:404)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:304)
	io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
	java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	com.twitter.finagle.util.BlockingTimeTrackingThreadFactory$$anon$1.run(BlockingTimeTrackingThreadFactory.scala:23)
	java.lang.Thread.run(Thread.java:748)
```

### Netty version
4.1.16, though a scan of the GitHub repo suggests it's still an issue.

### JVM version (e.g. `java -version`)
openjdk version "1.8.0_152"

### OS version (e.g. `uname -a`)
Centos 7

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java
codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java
codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java
diff --git a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java
index ae98bfea08b..aeeec3feb68 100644
--- a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java
+++ b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2MultiplexCodec.java
@@ -227,6 +227,9 @@ final void onHttp2Frame(ChannelHandlerContext ctx, Http2Frame frame) {
             if (settings.initialWindowSize() != null) {
                 initialOutboundStreamWindow = settings.initialWindowSize();
             }
+        } else {
+            // Send any other frames down the pipeline
+            ctx.fireChannelRead(frame);
         }
     }
 

diff --git a/codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java b/codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java
index ecdcdcf7c85..bec5cd964ee 100644
--- a/codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java
+++ b/codec-http2/src/test/java/io/netty/handler/codec/http2/Http2MultiplexCodecTest.java
@@ -170,6 +170,17 @@ public void inboundDataFrameShouldEmitWindowUpdateFrame() {
         verifyFramesMultiplexedToCorrectChannel(inboundStream, inboundHandler, 2);
     }
 
+    @Test
+    public void unhandledHttp2FramesShouldBePropagated() {
+        ByteBuf content = UnpooledByteBufAllocator.DEFAULT.buffer(8).writeLong(0);
+        Http2PingFrame decodedFrame = new DefaultHttp2PingFrame(content);
+
+        codec.onHttp2Frame(decodedFrame);
+        Http2PingFrame receivedPing = parentChannel.readInbound();
+        assertSame(receivedPing, decodedFrame);
+        assertTrue(receivedPing.release());
+    }
+
     @Test
     public void channelReadShouldRespectAutoRead() {
         LastInboundHandler inboundHandler = streamActiveAndWriteHeaders(inboundStream);
