[undertow-dev] occasional 502 from Apache HTTP Proxy
Tomaž Cerar
tomaz.cerar at gmail.com
Mon Jan 19 07:29:12 EST 2015
Edgar,
what is the version of Apache and mod_proxy module you are using.
maybe it will be easier to reproduce with exact version you have..
--
tomaz
On Mon, Jan 19, 2015 at 1:15 PM, Edgar Espina <espina.edgar at gmail.com>
wrote:
> The source code can be found here: https://github.com/jooby-project/jooby
>
> Undertow related classes are here:
> https://github.com/jooby-project/jooby/tree/master/jooby/src/main/java/org/jooby/internal/undertow
> .
> Server is built here:
> https://github.com/jooby-project/jooby/blob/master/jooby/src/main/java/org/jooby/internal/undertow/UndertowServer.java
> Response is sent here:
> https://github.com/jooby-project/jooby/blob/master/jooby/src/main/java/org/jooby/internal/undertow/UndertowResponse.java#L336-382
>
> My microweb-framework was built on top of Jetty, so for now I used the
> blocking API and follow more or less what we usually do with Servlets
> (acquire an outstream).
>
> I will review what I'm doing and try to figure it out what is going on too.
>
> Thanks for your help, Stuart.
>
>
>
>
> On Mon, Jan 19, 2015 at 2:12 AM, Stuart Douglas <sdouglas at redhat.com>
> wrote:
>
>> My best guess as to what is happening is that Undertow closing a
>> connection after a request is done for some reason, and the apache attempts
>> to re-use this connection without realising that it is dead.
>>
>> In general this should not happen, Undertow should only forcibly close a
>> connection if it knows that it is broken (e.g. a content length is set and
>> the full amount of content is not written). For a normal graceful close
>> Undertow should be sending Connection:close headers.
>>
>> I am going to investigate some more, and see if I can figure out what is
>> going on. It seems unlikely but is there any chance your code forcibly
>> closes the ServerConnection (HttpServerExchange.getConnection()) because
>> that could potentially cause this issue. Setting the exchange to
>> non-persistent after headers have been sent could also cause it.
>>
>> Stuart
>>
>> ----- Original Message -----
>> > From: "Edgar Espina" <espina.edgar at gmail.com>
>> > To: "Stuart Douglas" <sdouglas at redhat.com>
>> > Cc: undertow-dev at lists.jboss.org
>> > Sent: Monday, 19 January, 2015 2:53:06 PM
>> > Subject: Re: [undertow-dev] occasional 502 from Apache HTTP Proxy
>> >
>> > Done, but makes no difference. Still got the 502 random errors :S
>> >
>> > On Sun, Jan 18, 2015 at 11:13 PM, Stuart Douglas <sdouglas at redhat.com>
>> > wrote:
>> >
>> > > I had a play around with apache locally, and I could reproduce this in
>> > > some circumstances, and it looks like we are not setting a high enough
>> > > backlog by default.
>> > >
>> > > Can you try adding:
>> > >
>> > > undertow.setSocketOption(Options.BACKLOG, 1000)
>> > >
>> > > To your Undertow builder? I am going to increase this in our default
>> > > config upstream.
>> > >
>> > > Hopefully this is the issue that you are running into.
>> > >
>> > > Stuart
>> > >
>> > >
>> > > ----- Original Message -----
>> > > > From: "Edgar Espina" <espina.edgar at gmail.com>
>> > > > To: "Stuart Douglas" <sdouglas at redhat.com>
>> > > > Cc: undertow-dev at lists.jboss.org
>> > > > Sent: Monday, 19 January, 2015 12:10:16 PM
>> > > > Subject: Re: [undertow-dev] occasional 502 from Apache HTTP Proxy
>> > > >
>> > > > It is a default undertow instance with a HTTP listener, just set
>> work
>> > > > threads to 200. Is there a default idle timeout? I can' tell from
>> javadoc
>> > > > and looking at the code.
>> > > >
>> > > >
>> > > > On Sun, Jan 18, 2015 at 9:59 PM, Stuart Douglas <
>> sdouglas at redhat.com>
>> > > wrote:
>> > > >
>> > > > >
>> > > > >
>> > > > > Edgar Espina wrote:
>> > > > >
>> > > > >> I'm not, channel does it.
>> > > > >>
>> > > > >> Problem is present on both. For example, home page has a
>> > > content-length
>> > > > >> header but jquery.js use chunked.
>> > > > >>
>> > > > >
>> > > > > In general if you are serving static resources you are better off
>> > > setting
>> > > > > the content length (slightly more efficient, and the browser can
>> > > display
>> > > > > progress on downloads).
>> > > > >
>> > > > >
>> > > > >> Do I have to call .endExchange? or closing the output stream is
>> > > enough?
>> > > > >>
>> > > > >
>> > > > > Closing the output stream is enough. endExchange is automatically
>> > > called
>> > > > > once the call stack returns anyway, unless you have dispatched the
>> > > exchange
>> > > > > or started async IO.
>> > > > >
>> > > > > The 'connection reset by peer' error in the apache log while
>> reading
>> > > the
>> > > > > status like kinda indicates that the request does not even get to
>> this
>> > > > > point anyway, and the underlying TCP connection is probably being
>> torn
>> > > down
>> > > > > somehow.
>> > > > >
>> > > > > Do you have any kind of timeouts set? If you have an idle timeout
>> set
>> > > on
>> > > > > the listener there is a race where Undertow can close the channel
>> due
>> > > to
>> > > > > inactivity just as the front end starts to send a request.
>> > > > >
>> > > > > Stuart
>> > > > >
>> > > > >
>> > > > >> Thanks
>> > > > >>
>> > > > >> On Sun, Jan 18, 2015 at 9:48 PM, Stuart Douglas <
>> sdouglas at redhat.com
>> > > > >> <mailto:sdouglas at redhat.com>> wrote:
>> > > > >>
>> > > > >> Another question, are you setting a content length on the
>> > > responses?
>> > > > >> If not the channel will automatically set one if the
>> response fits
>> > > > >> inside a buffer, otherwise chunked encoding will be used.
>> > > > >>
>> > > > >> It might be helpful to know if this only happens on chunked,
>> fixed
>> > > > >> length or both.
>> > > > >>
>> > > > >> Stuart
>> > > > >>
>> > > > >> Edgar Espina wrote:
>> > > > >>
>> > > > >> latest: 1.2.0.Beta8
>> > > > >>
>> > > > >> On Sun, Jan 18, 2015 at 9:42 PM, Stuart Douglas
>> > > > >> <sdouglas at redhat.com <mailto:sdouglas at redhat.com>
>> > > > >> <mailto:sdouglas at redhat.com <mailto:sdouglas at redhat.com
>> >>>
>> > > wrote:
>> > > > >>
>> > > > >> Also what version of Undertow are you using?
>> > > > >>
>> > > > >> Stuart
>> > > > >>
>> > > > >> ----- Original Message -----
>> > > > >> > From: "Edgar Espina" <espina.edgar at gmail.com
>> > > > >> <mailto:espina.edgar at gmail.com>
>> > > > >> <mailto:espina.edgar at gmail.com <mailto:
>> espina.edgar at gmail.com
>> > > > >> >__>>
>> > > > >> > To: "Stuart Douglas" <sdouglas at redhat.com
>> > > > >> <mailto:sdouglas at redhat.com>
>> > > > >> <mailto:sdouglas at redhat.com <mailto:sdouglas at redhat.com
>> >>>
>> > > > >> > Cc: undertow-dev at lists.jboss.org
>> > > > >> <mailto:undertow-dev at lists.jboss.org>
>> > > > >> <mailto:undertow-dev at lists.__jboss.org
>> > > > >> <mailto:undertow-dev at lists.jboss.org>>
>> > > > >> > Sent: Monday, 19 January, 2015 11:13:21 AM
>> > > > >> > Subject: Re: [undertow-dev] occasional 502 from
>> Apache HTTP
>> > > > >> Proxy
>> > > > >> >
>> > > > >> > found this in apache:
>> > > > >> >
>> > > > >> > (104) Connection reset by peer: proxy: error reading
>> status
>> > > > >> line from
>> > > > >> > remote server
>> > > > >> >
>> > > > >> > but nothing in undertow.
>> > > > >> >
>> > > > >> > got 502 on HTTP GET. Sometimes while calling the home
>> page
>> > > / or
>> > > > >> when page
>> > > > >> > loads OK, got 502 on page resources (js, css, images).
>> > > > >> >
>> > > > >> > I call startBlocking and use the outputstream to
>> write the
>> > > > >> response, when
>> > > > >> > everything has been written I call the
>> "outputstream.close"
>> > > > >> method. Do I
>> > > > >> > need to call exchange.endExchange too?
>> > > > >> >
>> > > > >> > Thanks
>> > > > >> >
>> > > > >> > On Sun, Jan 18, 2015 at 8:52 PM, Stuart Douglas
>> > > > >> <sdouglas at redhat.com <mailto:sdouglas at redhat.com>
>> > > > >> <mailto:sdouglas at redhat.com <mailto:sdouglas at redhat.com
>> >>>
>> > > wrote:
>> > > > >> >
>> > > > >> > > Is there any info in the log? Or is there any
>> specific
>> > > type
>> > > > >> of
>> > > > >> request
>> > > > >> > > that causes this?
>> > > > >> > >
>> > > > >> > > Stuart
>> > > > >> > >
>> > > > >> > >
>> > > > >> > > ----- Original Message -----
>> > > > >> > > > From: "Edgar Espina" <espina.edgar at gmail.com
>> > > > >> <mailto:espina.edgar at gmail.com>
>> > > > >> <mailto:espina.edgar at gmail.com <mailto:
>> espina.edgar at gmail.com
>> > > > >> >__>>
>> > > > >> > > > To: undertow-dev at lists.jboss.org
>> > > > >> <mailto:undertow-dev at lists.jboss.org>
>> > > > >> <mailto:undertow-dev at lists.__jboss.org
>> > > > >> <mailto:undertow-dev at lists.jboss.org>>
>> > > > >> > > > Sent: Monday, 19 January, 2015 9:42:19 AM
>> > > > >> > > > Subject: [undertow-dev] occasional 502 from
>> Apache HTTP
>> > > > >> Proxy
>> > > > >> > > >
>> > > > >> > > > Hi,
>> > > > >> > > >
>> > > > >> > > > I've an Undertow application behind apache reverse
>> > > proxy,
>> > > > >> trying to load
>> > > > >> > > a
>> > > > >> > > > page displays error 502 proxy error.
>> > > > >> > > >
>> > > > >> > > > Still couldn't find why so I wonder if any of you
>> find
>> > > a
>> > > > >> similar problem
>> > > > >> > > with
>> > > > >> > > > Undertow and Apache.
>> > > > >> > > >
>> > > > >> > > > Please note this is our first app on top of
>> Undertow,
>> > > > >> existing apps
>> > > > >> > > running
>> > > > >> > > > on Tomcat/Jetty are OK.
>> > > > >> > > >
>> > > > >> > > > Appreciate any help.
>> > > > >> > > >
>> > > > >> > > > Thanks
>> > > > >> > > >
>> > > > >> > > > --
>> > > > >> > > > edgar
>> > > > >> > > >
>> > > > >> > > > _________________________________________________
>> > > > >> > > > undertow-dev mailing list
>> > > > >> > > > undertow-dev at lists.jboss.org
>> > > > >> <mailto:undertow-dev at lists.jboss.org>
>> > > > >> <mailto:undertow-dev at lists.__jboss.org
>> > > > >> <mailto:undertow-dev at lists.jboss.org>>
>> > > > >> > > >
>> > > https://lists.jboss.org/__mailman/listinfo/undertow-dev
>> > > > >> <https://lists.jboss.org/mailman/listinfo/undertow-dev>
>> > > > >> > >
>> > > > >> >
>> > > > >> >
>> > > > >> >
>> > > > >> > --
>> > > > >> > edgar
>> > > > >> >
>> > > > >>
>> > > > >>
>> > > > >>
>> > > > >>
>> > > > >> --
>> > > > >> edgar
>> > > > >>
>> > > > >>
>> > > > >>
>> > > > >>
>> > > > >> --
>> > > > >> edgar
>> > > > >>
>> > > > >
>> > > >
>> > > >
>> > > > --
>> > > > edgar
>> > > >
>> > >
>> >
>> >
>> >
>> > --
>> > edgar
>> >
>>
>
>
>
> --
> edgar
>
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