[undertow-dev] occasional 502 from Apache HTTP Proxy
Tomaž Cerar
tomaz.cerar at gmail.com
Mon Jan 19 07:57:41 EST 2015
Maybe related to
http://stackoverflow.com/questions/169453/bad-gateway-502-error-with-apache-mod-proxy-and-tomcat
or
http://qnalist.com/questions/4502641/users-httpd-mod-proxy-ignores-incompleteness-of-chunked-coding-response-from-backend
On Mon, Jan 19, 2015 at 1:33 PM, Edgar Espina <espina.edgar at gmail.com>
wrote:
> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/undertow-dev/attachments/20150119/b7e91d3c/attachment-0001.html
More information about the undertow-dev
mailing list