7:04 a.m.
Hi Jason,
I believe the close() call is coming from me declaring the writer in a
try-with-resources statement.
Here's a jstack from just now, where my CPU is sitting at 96%:
https://gist.github.com/michaelhixson/8a6f2ebf4b167fb1b67e
-Michael
On Fri, May 29, 2015 at 9:28 PM, Jason T. Greene
<jason.greene(a)redhat.com> wrote:
Hi Michael,
That stack trace seems to show a close() call to the writer in your handler, but I
don't see that call in the code?
Note that getting I/o exceptions during write and close calls is normal after a client
abnormally terminates. You typically just drop the exception (perhaps trace logging).
Could you get a jstack output under the scenario where you see high CPU load?
> On May 28, 2015, at 6:19 PM, Michael Hixson <michael.hixson(a)gmail.com> wrote:
>
> Hello,
>
> I'm trying out HTTP/2 with undertow-core in my application, and I see
> that I'm able to get the server into a bad state pretty reliably by
> refreshing quickly in my browser. It stops responding to requests and
> the CPU usage of the Java process starts to climb towards 100%.
>
> I was able to replicate this in the HTTP/2 example in the latest from
> the master branch, by changing the main HttpHandler. This is what I
> put in Http2Server#main(String[]):
>
> Undertow server = Undertow.builder()
> .setServerOption(UndertowOptions.ENABLE_HTTP2, true)
> .setServerOption(UndertowOptions.ENABLE_SPDY, true)
> .addHttpListener(8080, bindAddress)
> .addHttpsListener(8443, bindAddress, sslContext)
> .setHandler(new HttpHandler() {
> @Override
> public void handleRequest(HttpServerExchange exchange) {
> if (exchange.isInIoThread()) {
> exchange.dispatch(this);
> return;
> }
> exchange.startBlocking();
> exchange.getResponseHeaders().put(
> new HttpString("Content-Type"), "text/html");
> try (BufferedWriter writer = new BufferedWriter(
> new OutputStreamWriter(
> exchange.getOutputStream(),
> StandardCharsets.UTF_8))) {
> writer.append("<!DOCTYPE html><html>\n");
> for (int i = 0; i < 100; i++) {
> writer.append(
> "<link rel=\"stylesheet\" href=\"/" +
i + ".css\">\n");
> }
> writer.append("hello");
> } catch (IOException e) {
> e.printStackTrace();
> throw new RuntimeException(e);
> }
> }
> }).build();
>
> Then I go to https://localhost:8443/ in a browser and hold down F5 for
> a bit. I start seeing errors like this:
>
> java.nio.channels.ClosedChannelException
> at
io.undertow.server.protocol.framed.AbstractFramedStreamSinkChannel.write(AbstractFramedStreamSinkChannel.java:396)
> at org.xnio.channels.Channels.writeFinalBasic(Channels.java:961)
> at
io.undertow.server.protocol.framed.AbstractFramedStreamSinkChannel.writeFinal(AbstractFramedStreamSinkChannel.java:420)
> at
org.xnio.conduits.StreamSinkChannelWrappingConduit.writeFinal(StreamSinkChannelWrappingConduit.java:66)
> at
org.xnio.conduits.ConduitStreamSinkChannel.writeFinal(ConduitStreamSinkChannel.java:104)
> at
io.undertow.channels.DetachableStreamSinkChannel.writeFinal(DetachableStreamSinkChannel.java:195)
> at
io.undertow.server.HttpServerExchange$WriteDispatchChannel.writeFinal(HttpServerExchange.java:1882)
> at
io.undertow.io.UndertowOutputStream.writeBufferBlocking(UndertowOutputStream.java:288)
> at io.undertow.io.UndertowOutputStream.close(UndertowOutputStream.java:331)
> at sun.nio.cs.StreamEncoder.implClose(StreamEncoder.java:320)
> at sun.nio.cs.StreamEncoder.close(StreamEncoder.java:149)
> at java.io.OutputStreamWriter.close(OutputStreamWriter.java:233)
> at java.io.BufferedWriter.close(BufferedWriter.java:266)
> at
io.undertow.examples.http2.Http2Server$1.handleRequest(Http2Server.java:94)
> at io.undertow.server.Connectors.executeRootHandler(Connectors.java:199)
> at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:774)
> at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
> at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
> at java.lang.Thread.run(Thread.java:745)
>
> In case it helps, I saw a different error in my real (not undertow
> example) application when I started seeing the same effects visibly
> (site down and CPU climbing to 100%). Maybe it is the same root cause
> but just being caught/logged differently:
>
> ERROR [2015-05-28 14:23:59,804] org.xnio.nio: XNIO000011: Task
> io.undertow.server.protocol.framed.AbstractFramedChannel$2@308b5f1f
> failed with an exception
> java.lang.IllegalStateException: null
> at
io.undertow.server.protocol.framed.AbstractFramedStreamSinkChannel.getBuffer(AbstractFramedStreamSinkChannel.java:523)
> ~[undertow-core-1.3.0.Beta1-SNAPSHOT.jar:1.3.0.Beta1-SNAPSHOT]
> at
io.undertow.server.protocol.framed.AbstractFramedChannel.flushSenders(AbstractFramedChannel.java:496)
> ~[undertow-core-1.3.0.Beta1-SNAPSHOT.jar:1.3.0.Beta1-SNAPSHOT]
> at
io.undertow.server.protocol.framed.AbstractFramedChannel$2.run(AbstractFramedChannel.java:581)
> ~[undertow-core-1.3.0.Beta1-SNAPSHOT.jar:1.3.0.Beta1-SNAPSHOT]
> at org.xnio.nio.WorkerThread.safeRun(WorkerThread.java:560)
> ~[xnio-nio-3.3.1.Final.jar:3.3.1.Final]
> at org.xnio.nio.WorkerThread.run(WorkerThread.java:462)
> ~[xnio-nio-3.3.1.Final.jar:3.3.1.Final]
>
> I see the same behavior in my real application with both undertow-core
> 1.2.6.Final and 1.3.0.Beta1-SNAPSHOT (the latter installed locally
> from source). I only tried the Http2Server example in the latest
> version though.
>
> -Michael
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