Re: Apache server returns early before process is complete

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You configure timeout at the client side. Apache is at the server side.
Server doesn't have a concept of time it could take days to run and not
care.

mod_perl code is where you are sending the http return status to make sure
the client doesn't timeout waiting for the server to respond.

On Wed, Apr 23, 2025, 2:19=E2=80=AFPM Joseph He <[email protected]> =
wrote:

> Thanks, all.
> Is that Apache timeout controlled by its configuration "Timeout"?
> I don't think it has anything to do with modPerl. Am I missing something?
> Thanks.
>
> On Wed, Apr 23, 2025 at 1:41=E2=80=AFPM Mithun Bhattacharya <mithnb@gmail=
.com>
> wrote:
>
>> Timeout happens because of how we handle the request. Timeout is
>> basically no response came back. Why that happens is because we think we
>> want to have a correct response. Unfortunately for long running requests
>> the correct response shouldn't be via http response code or we face
>> situations like this. Instead reply with a 200 OK immediately and then
>> provide correct status in the message body. Once a response code/header =
has
>> been sent timeout won't trigger and you could potentially hold the
>> connection for hours without a problem.
>>
>> On Wed, Apr 23, 2025, 9:32=E2=80=AFAM Andreas Mock <[email protected]>=
 wrote:
>>
>>> Hi Joseph,
>>>
>>> your description is very vague, so can only answer on some assumptions:
>>>
>>> It sounds like a timeout is fired somewhere.
>>>
>>> Best advice in these situations: Log as many steps as you can. Keep you=
r
>>> eyes open on TCP/IP and higher level timeouts.
>>>
>>> Declare only ONE instance responsible for a retry: Either the app serve=
r
>>> calling the dispatcher with several tries or the dispatcher trying for
>>> himself. Not both.
>>>
>>> Best regards
>>> Andreas
>>>
>>>
>>> Am 23.04.2025 um 16:21 schrieb Joseph He:
>>> > All, good day.
>>> >
>>> > Here is the issue I have.
>>> > My entire application is running on ModPerl/Apache environment.
>>> > I send Http::Request with data load from my App server to a dispatch
>>> > server thru LWP::UserAgent, I set the timeout 600 seconds.
>>> >
>>> > The dispatch server is supposed to manipulate the data and send the
>>> > data to an external SFTP server. Because the SFTP can fail, it will
>>> > keep trying up to 4 times with 30 seconds sleep in case that SFTP
>>> > connection fails.
>>> >
>>> > Recently, I found that I uploaded the file twice sometimes. I figured
>>> > out the root cause is that my Dispatch server returns 'failure' at 6
>>> > minutes while it keeps trying to do the SFTP. The App server
>>> > received HTTP::Response with error status so it issued another call t=
o
>>> > send data. It turns out I uploaded the identified file twice.
>>> >
>>> > Anybody has this sort of experience? Why does the dispatch server
>>> > return 'error' while it still processes the data?
>>> >
>>> > Thanks a lot,
>>> > Joseph
>>> >
>>>
>>

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<div dir=3D"auto"><p dir=3D"ltr">You configure timeout at the client side. =
Apache is at the server side. Server doesn&#39;t have a concept of time it =
could take days to run and not care.</p><p dir=3D"ltr">mod_perl code is whe=
re you are sending the http return status to make sure the client doesn&#39=
;t timeout waiting for the server to respond.</p></div><br><div class=3D"gm=
ail_quote gmail_quote_container"><div dir=3D"ltr" class=3D"gmail_attr">On W=
ed, Apr 23, 2025, 2:19=E2=80=AFPM Joseph He &lt;<a href=3D"mailto:joseph.he=
[email protected]">[email protected]</a>&gt; wrote:<br></div><blockquo=
te class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px =
solid rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr">Thanks, all.<div>=
Is that Apache timeout controlled by its configuration=C2=A0&quot;Timeout&q=
uot;?=C2=A0</div><div>I don&#39;t think it has anything to do with modPerl.=
 Am I=C2=A0missing something?</div><div>Thanks.</div></div><br><div class=
=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Wed, Apr 23, 2025=
 at 1:41=E2=80=AFPM Mithun Bhattacharya &lt;<a href=3D"mailto:mithnb@gmail.=
com" target=3D"_blank" rel=3D"noreferrer">[email protected]</a>&gt; wrote:<b=
r></div><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex=
;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir=3D"auto"=
>Timeout happens because of how we handle the request. Timeout is basically=
 no response came back. Why that happens is because we think we want to hav=
e a correct response. Unfortunately for long running requests the correct r=
esponse shouldn&#39;t be via http response code or we face situations like =
this. Instead reply with a 200 OK immediately and then provide correct stat=
us in the message body. Once a response code/header has been sent timeout w=
on&#39;t trigger and you could potentially hold the connection for hours wi=
thout a problem.</div><br><div class=3D"gmail_quote"><div dir=3D"ltr" class=
=3D"gmail_attr">On Wed, Apr 23, 2025, 9:32=E2=80=AFAM Andreas Mock &lt;<a h=
ref=3D"mailto:[email protected]" target=3D"_blank" rel=3D"noreferrer">and=
[email protected]</a>&gt; wrote:<br></div><blockquote class=3D"gmail_quote" =
style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);pa=
dding-left:1ex">Hi Joseph,<br>
<br>
your description is very vague, so can only answer on some assumptions:<br>
<br>
It sounds like a timeout is fired somewhere.<br>
<br>
Best advice in these situations: Log as many steps as you can. Keep your <b=
r>
eyes open on TCP/IP and higher level timeouts.<br>
<br>
Declare only ONE instance responsible for a retry: Either the app server <b=
r>
calling the dispatcher with several tries or the dispatcher trying for <br>
himself. Not both.<br>
<br>
Best regards<br>
Andreas<br>
<br>
<br>
Am 23.04.2025 um 16:21 schrieb Joseph He:<br>
&gt; All, good day.<br>
&gt;<br>
&gt; Here is the issue I have.<br>
&gt; My entire application is running on ModPerl/Apache environment.<br>
&gt; I send Http::Request with data load from my App server to a dispatch <=
br>
&gt; server thru LWP::UserAgent, I set the timeout 600 seconds.<br>
&gt;<br>
&gt; The dispatch server is supposed to manipulate the data and send the <b=
r>
&gt; data to an external SFTP server. Because the SFTP can fail, it will <b=
r>
&gt; keep trying up to 4 times with 30 seconds sleep in case that SFTP <br>
&gt; connection fails.<br>
&gt;<br>
&gt; Recently, I found that I uploaded the file twice sometimes. I figured =
<br>
&gt; out the root cause is that my Dispatch server returns &#39;failure&#39=
; at 6 <br>
&gt; minutes while it keeps trying to do the SFTP. The App server <br>
&gt; received=C2=A0HTTP::Response with error status so it issued another ca=
ll to <br>
&gt; send data. It turns out I uploaded the identified file twice.<br>
&gt;<br>
&gt; Anybody has this sort of experience? Why does the dispatch=C2=A0server=
 <br>
&gt; return &#39;error&#39; while it still processes the data?<br>
&gt;<br>
&gt; Thanks a lot,<br>
&gt; Joseph<br>
&gt;<br>
</blockquote></div>
</blockquote></div>
</blockquote></div>

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