[undertow-dev] http/2 server starts dying after rapid refresh
Michael Hixson
michael.hixson at gmail.com
Sat May 30 01:26:02 EDT 2015
Also here is a jmap -histo from a little later:
https://gist.github.com/michaelhixson/de6ede25fdb79a4f25b4
(apologies in advance if gmail sends this email twice like my last one)
-Michael
On Fri, May 29, 2015 at 10:04 PM, Michael Hixson
<michael.hixson at gmail.com> wrote:
> 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 at 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 at 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 at 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
>>> _______________________________________________
>>> undertow-dev mailing list
>>> undertow-dev at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/undertow-dev
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