[undertow-dev] occasional 502 from Apache HTTP Proxy
Edgar Espina
espina.edgar at gmail.com
Mon Jan 19 07:33:13 EST 2015
Sure, it is 2.2.15.
On Mon, Jan 19, 2015 at 9:29 AM, Tomaž Cerar <tomaz.cerar at gmail.com> wrote:
> 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
>>
>> _______________________________________________
>> undertow-dev mailing list
>> undertow-dev at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/undertow-dev
>>
>
>
--
edgar
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