[prev in list] [next in list] [prev in thread] [next in thread] 

List:       apache-httpd-users
Subject:    [users@httpd] RE: [EXTERNAL] Re: [users@httpd] timeout and keepalive parameter in ProxyPass
From:       "Orendt, John" <john.p.orendt () medtronic ! com ! INVALID>
Date:       2021-10-19 14:48:37
Message-ID: MW4PR05MB863365B1F435ABD0F2BD786FA1BD9 () MW4PR05MB8633 ! namprd05 ! prod ! outlook ! com
[Download RAW message or body]

[Attachment #2 (multipart/alternative)]

[Attachment #4 (text/plain)]

Hi

I use a different approach to these types of requests.

The back end request immediately returns a status message "Request Received"

On Subsequent Requests returns a status message "Working"

Finally, Subsequent Request returns a status message "Ready" with results.

John Orendt
John.p.orendt@medtronic.com

From: Usha Nayak <ushanay@gmail.com>
Sent: Tuesday, October 19, 2021 10:37 AM
To: users@httpd.apache.org
Subject: [EXTERNAL] Re: [users@httpd] timeout and keepalive parameter in ProxyPass

Hello

Thank you for your response. However, I'm still a bit fuzzy when it comes to the \
keepalive and timeout attribute.

I understand keepalive=On attribute by itself but in combination with timeout is \
where I'm unclear.

In the scenario that I presented with following:

  *    timeout=3600 keepalive=On attributes
  *    backend server taking a long time processing the request sent by client ( \
note: no streaming any data from server yet since it's busy processing the request, \
                let's say processing time on server is 4 hrs )
  *    OS settings are set to send TCP Keep alive packet in every 2 mins

My guess:

  *   With TCP keep alive probes sent and ACK between 'Apache httpd' machine and \
'Backend server' machine, we can be assured that there's no inactive or idle TCP \
                connection.
  *   But, from the 'Apache Httpd' application point of view, it hasn't received the \
data from the server in 1 hr(3600), and therefore 'Apache Httpd' will initiate a \
timeout. When the 'Backend Server' is ready in 4 hrs to stream the response back, \
there's no ' Apache Httpd' client to receive the response. Please do correct me if \
I'm thinking this incorrectly,

Appreciate all the help

Thanks.


On Wed, Oct 13, 2021 at 10:03 AM Dino Ciuffetti \
<dino@tuxweb.it<mailto:dino@tuxweb.it>> wrote: The global "Timeout" parameter is \
needed to set the length of time Apache httpd will wait for I/O in various \
circumstances. https://httpd.apache.org/docs/2.4/mod/core.html#timeout<https://urldefe \
nse.com/v3/__https:/httpd.apache.org/docs/2.4/mod/core.html*timeout__;Iw!!NFcUtLLUcw!DmkJVqMAt4NaSGwLZq93nIthjgNb1gK5MwyqdCke2kFmEvHGUM062jIb-qTQ7np89F8i_g$>



The "keepalive" attribute of ProxyPass can be used to fool your network equipments \
(like intermediate firewalls) to mantain the tcp connection between apache and its \
backends open even when no data is passing from and to the wires. Some network \
equipment like firewalls tend to drop inactive (silent) connections too early (from \
my experience ~30 min but your mileage may vary).

The "timeout" attribute of ProxyPass is the number of seconds Apache httpd waits for \
data sent by / to the backend. So in your case apache will close a inactive \
connection with the backend in 1hr, but while your backend continue to stream data \
the connection will be kept open. Yes, it's a sort of application timeout.

There is also the "connectiontimeout" attribute of ProxyPass that will consider a new \
TCP connection with the backend not valid if it takes the specified time to complete \
(TCP SYN + SYN/ACK + ACK) so it can be retried earlier.




13 ottobre 2021 16:22, "Usha Nayak" \
<ushanay@gmail.com<mailto:ushanay@gmail.com?to=%22Usha%20Nayak%22%20%3Cushanay@gmail.com%3E>> \
wrote: Hello
Need help in understanding the highlighted parameters:
ProxyPass "/example" \
"http://backend.example.com<https://urldefense.com/v3/__http:/backend.example.com__;!! \
NFcUtLLUcw!DmkJVqMAt4NaSGwLZq93nIthjgNb1gK5MwyqdCke2kFmEvHGUM062jIb-qTQ7npt-Xfx7Q$>" \
timeout=3600 keepalive=On keepalive parameter - As I understand relates to TCP or \
socket keep alive probes that are sent to prevent idle connection. \
[cid:image001.png@01D7C4D6.CF3A0310] My confusion is :
Assuming the backend server takes 4 hrs to process a request and I have 'keepalive \
on' in Apache httpd with the OS setting to send tcp probes every 2 minutes. Backend \
server and Apache httpd are sending TCP keep alive packets to indicate the socket \
connection is not idle.

  *   In this case, would the 'apache httpd' close the connection in 1 hr ( timeout = \
3600) because the 'apache httpd' didn't get the http data? Is this timeout 'apache \
httpd' application timeout ? Appreciate help.
Thanks.

[CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is \
proprietary to Medtronic and is intended for use only by the individual or entity to \
which it is addressed, and may contain information that is private, privileged, \
confidential or exempt from disclosure under applicable law. If you are not the \
intended recipient or it appears that this mail has been forwarded to you without \
proper authority, you are notified that any use or dissemination of this information \
in any manner is strictly prohibited. In such cases, please delete this mail from \
your records. To view this notice in other languages you can either select the \
following link or manually copy and paste the link into the address bar of a web \
browser: http://emaildisclaimer.medtronic.com


[Attachment #5 (text/html)]

<html xmlns:v="urn:schemas-microsoft-com:vml" \
xmlns:o="urn:schemas-microsoft-com:office:office" \
xmlns:w="urn:schemas-microsoft-com:office:word" \
xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" \
xmlns="http://www.w3.org/TR/REC-html40"> <head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<!--[if !mso]><style>v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style><![endif]--><style><!--
/* Font Definitions */
@font-face
	{font-family:Wingdings;
	panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
	{font-family:"Cambria Math";
	panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
	{font-family:DengXian;
	panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
	{font-family:Calibri;
	panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
	{font-family:"\@DengXian";
	panose-1:2 1 6 0 3 1 1 1 1 1;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
	{margin:0in;
	font-size:11.0pt;
	font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
	{mso-style-priority:99;
	color:blue;
	text-decoration:underline;}
span.EmailStyle18
	{mso-style-type:personal-reply;
	font-family:"Calibri",sans-serif;
	color:windowtext;}
.MsoChpDefault
	{mso-style-type:export-only;
	font-family:"Calibri",sans-serif;}
@page WordSection1
	{size:8.5in 11.0in;
	margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
	{page:WordSection1;}
/* List Definitions */
@list l0
	{mso-list-id:386994291;
	mso-list-template-ids:-2063157950;}
@list l0:level1
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Symbol;}
@list l0:level2
	{mso-level-number-format:bullet;
	mso-level-text:o;
	mso-level-tab-stop:1.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:"Courier New";
	mso-bidi-font-family:"Times New Roman";}
@list l0:level3
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:1.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l0:level4
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:2.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l0:level5
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:2.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l0:level6
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:3.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l0:level7
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:3.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l0:level8
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:4.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l0:level9
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:4.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1
	{mso-list-id:447969769;
	mso-list-template-ids:1551504282;}
@list l1:level1
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Symbol;}
@list l1:level2
	{mso-level-number-format:bullet;
	mso-level-text:o;
	mso-level-tab-stop:1.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:"Courier New";
	mso-bidi-font-family:"Times New Roman";}
@list l1:level3
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:1.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1:level4
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:2.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1:level5
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:2.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1:level6
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:3.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1:level7
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:3.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1:level8
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:4.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l1:level9
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:4.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2
	{mso-list-id:1212156535;
	mso-list-template-ids:1818000580;}
@list l2:level1
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Symbol;}
@list l2:level2
	{mso-level-number-format:bullet;
	mso-level-text:o;
	mso-level-tab-stop:1.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:"Courier New";
	mso-bidi-font-family:"Times New Roman";}
@list l2:level3
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:1.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2:level4
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:2.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2:level5
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:2.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2:level6
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:3.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2:level7
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:3.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2:level8
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:4.0in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
@list l2:level9
	{mso-level-number-format:bullet;
	mso-level-text:;
	mso-level-tab-stop:4.5in;
	mso-level-number-position:left;
	text-indent:-.25in;
	mso-ansi-font-size:10.0pt;
	font-family:Wingdings;}
ol
	{margin-bottom:0in;}
ul
	{margin-bottom:0in;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word">
<div class="WordSection1">
<p class="MsoNormal">Hi<o:p></o:p></p>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<p class="MsoNormal">I use a different approach to these types of \
requests.<o:p></o:p></p> <p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<p class="MsoNormal">The back end request immediately returns a status message \
"Request Received"<o:p></o:p></p> <p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<p class="MsoNormal">On Subsequent Requests returns a status message \
"Working"<o:p></o:p></p> <p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<p class="MsoNormal">Finally, Subsequent Request returns a status message "Ready" \
with results.<o:p></o:p></p> <p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<p class="MsoNormal">John Orendt<o:p></o:p></p>
<p class="MsoNormal">John.p.orendt@medtronic.com<o:p></o:p></p>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> Usha Nayak &lt;ushanay@gmail.com&gt; <br>
<b>Sent:</b> Tuesday, October 19, 2021 10:37 AM<br>
<b>To:</b> users@httpd.apache.org<br>
<b>Subject:</b> [EXTERNAL] Re: [users@httpd] timeout and keepalive parameter in \
ProxyPass<o:p></o:p></p> </div>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
<div>
<div>
<p class="MsoNormal">Hello<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class="MsoNormal">Thank you for your response. However, I'm still a bit fuzzy when \
it comes to the keepalive and timeout attribute.<br> <br>
I understand keepalive=On attribute by itself but in combination with timeout is \
where I'm unclear.<br> <br>
In the scenario that I presented with following:<o:p></o:p></p>
</div>
<div>
<ul type="disc">
<li class="MsoNormal" \
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1"> \
&nbsp;timeout=3600 keepalive=On attributes<o:p></o:p></li><li class="MsoNormal" \
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1"> \
&nbsp;backend server taking a long time processing the request sent by client ( note: \
no streaming any data from server yet since it's busy processing the request, let's \
say processing time on server is 4 hrs )<o:p></o:p></li><li class="MsoNormal" \
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1"> \
&nbsp;OS settings are set to send TCP Keep alive packet in every 2 mins \
&nbsp;<o:p></o:p></li></ul> <p class="MsoNormal"><br>
My guess:<o:p></o:p></p>
<ul type="disc">
<li class="MsoNormal" \
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l1 level1 lfo2"> \
With TCP keep alive probes sent and ACK between 'Apache httpd' machine and 'Backend \
server' machine, we can be assured that there's no inactive or idle TCP \
connection.<o:p></o:p></li><li class="MsoNormal" \
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l1 level1 lfo2"> \
But, from the 'Apache Httpd' application point of view, it hasn't received the data \
from the server in 1 hr(3600), and therefore 'Apache Httpd' will initiate a timeout. \
When the 'Backend Server' is ready in 4 hrs to stream the response back, there's no ' \
Apache  Httpd' client to receive the response.<o:p></o:p></li></ul>
</div>
<div>
<div>
<p class="MsoNormal">Please do correct me if I'm thinking this \
incorrectly,<o:p></o:p></p> </div>
<div>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class="MsoNormal">Appreciate all the help<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class="MsoNormal">Thanks.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p>&nbsp;</o:p></p>
</div>
<div>
<p class="MsoNormal">On Wed, Oct 13, 2021 at 10:03 AM Dino Ciuffetti &lt;<a \
href="mailto:dino@tuxweb.it">dino@tuxweb.it</a>&gt; wrote:<o:p></o:p></p> </div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in \
6.0pt;margin-left:4.8pt;margin-right:0in"> <div>
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">The global \
&quot;Timeout&quot; parameter is needed to set the length of time Apache httpd will \
wait for I/O in various circumstances.<br> <a \
href="https://urldefense.com/v3/__https:/httpd.apache.org/docs/2.4/mod/core.html*timeo \
ut__;Iw!!NFcUtLLUcw!DmkJVqMAt4NaSGwLZq93nIthjgNb1gK5MwyqdCke2kFmEvHGUM062jIb-qTQ7np89F8i_g$" \
target="_blank">https://httpd.apache.org/docs/2.4/mod/core.html#timeout</a><br> <br>
<br>
The &quot;keepalive&quot; attribute of ProxyPass can be used to fool your network \
equipments (like intermediate firewalls) to mantain the tcp connection between apache \
and its backends open even when no data is passing from and to the wires. Some \
network equipment like  firewalls tend to drop inactive (silent) connections too \
early (from my experience ~30 min but your mileage may vary).<br> <br>
The &quot;timeout&quot; attribute of ProxyPass is the number of seconds Apache httpd \
waits for data sent by / to the backend. So in your case apache will close a inactive \
connection with the backend in 1hr, but while your backend continue to stream data \
the connection  will be kept open. Yes, it's a sort of application timeout.<br>
<br>
There is also the &quot;connectiontimeout&quot; attribute of ProxyPass that will \
consider a new TCP connection with the backend not valid if it takes the specified \
time to complete (TCP SYN + SYN/ACK + ACK) so it can be retried earlier.<br> <br>
<br>
<br>
<br>
13 ottobre 2021 16:22, &quot;Usha Nayak&quot; &lt;<a \
href="mailto:ushanay@gmail.com?to=%22Usha%20Nayak%22%20%3Cushanay@gmail.com%3E" \
target="_blank">ushanay@gmail.com</a>&gt; wrote:<o:p></o:p></span></p> <blockquote \
style="margin-top:5.0pt;margin-bottom:5.0pt"> <div>
<div>
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">Hello<o:p></o:p></span></p>
 <div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">Need help in \
understanding the highlighted parameters:<o:p></o:p></span></p> </div>
<div>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:&quot;Courier \
New&quot;;color:#112288">ProxyPass</span></b><span \
style="font-size:10.0pt;font-family:&quot;Courier New&quot;;color:black"> \
</span><span style="font-size:10.0pt;font-family:&quot;Courier \
New&quot;;color:#006600">&quot;/example&quot;</span><span \
style="font-size:10.0pt;font-family:&quot;Courier New&quot;;color:black"> \
</span><span style="font-size:10.0pt;font-family:&quot;Courier \
New&quot;;color:#006600">&quot;<a \
href="https://urldefense.com/v3/__http:/backend.example.com__;!!NFcUtLLUcw!DmkJVqMAt4NaSGwLZq93nIthjgNb1gK5MwyqdCke2kFmEvHGUM062jIb-qTQ7npt-Xfx7Q$" \
target="_blank">http://backend.example.com</a>&quot;</span><span \
style="font-size:10.0pt;font-family:&quot;Courier New&quot;;color:black"> \
</span><span style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif;color:black;background:yellow">timeout=3600</span><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif"> <span \
style="color:black;background:yellow">keepalive=On</span><o:p></o:p></span></p> \
</div> <div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">keepalive parameter \
- As I understand relates to TCP or socket keep alive probes that are sent to prevent \
idle connection.<o:p></o:p></span></p> </div>
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif"><img border="0" \
width="1631" height="94" style="width:16.9916in;height:.9833in" id="Picture_x0020_1" \
src="cid:image001.png@01D7C4D6.CF3A0310"></span><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif"><o:p></o:p></span></p>
 </div>
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">My confusion is \
:<o:p></o:p></span></p> </div>
<blockquote style="margin-left:30.0pt;margin-right:0in">
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">Assuming the \
backend server takes 4 hrs to process a request and I have 'keepalive on' in Apache \
httpd with the OS setting to send tcp probes every 2 minutes. Backend server  and \
Apache httpd are sending TCP keep alive packets to indicate the socket connection is \
not idle.<o:p></o:p></span></p> </div>
</blockquote>
<blockquote style="margin-left:30.0pt;margin-right:0in">
<ul type="disc">
<li class="MsoNormal" \
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l2 level1 lfo3"> \
<span style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">In this case, \
would the 'apache httpd' close the connection in 1 hr ( timeout = 3600) because the \
'apache httpd' didn't get the http data? Is this timeout 'apache httpd' application \
timeout ?<o:p></o:p></span></li></ul> </blockquote>
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">Appreciate \
help.<o:p></o:p></span></p> </div>
<div>
<p class="MsoNormal"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif">Thanks.<o:p></o:p></span></p>
 </div>
</div>
</div>
</div>
</blockquote>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span \
style="font-size:10.0pt;font-family:&quot;Arial&quot;,sans-serif"><o:p>&nbsp;</o:p></span></p>
 </div>
</div>
</blockquote>
</div>
</div>
</div>
[CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is \
proprietary to Medtronic and is intended for use only by the individual or entity to \
which it is addressed, and may contain information that is private, privileged, \
confidential or  exempt from disclosure under applicable law. If you are not the \
intended recipient or it appears that this mail has been forwarded to you without \
proper authority, you are notified that any use or dissemination of this information \
in any manner is strictly  prohibited. In such cases, please delete this mail from \
your records. To view this notice in other languages you can either select the \
following link or manually copy and paste the link into the address bar of a web \
browser: http://emaildisclaimer.medtronic.com </body>
</html>


["image001.png" (image/png)]

[prev in list] [next in list] [prev in thread] [next in thread] 

Configure | About | News | Add a list | Sponsored by KoreLogic