PHP stops page unexpectedly after executing some lines, segfaults

Question

PHP Version = 5.3, OS = CentOS 6, Provider = Rackspace, Type = Cloud

---

QUESTION

So I have a php page naming page_two.php of 195 lines. I call this page from page_one.php in the following way:

if(result=='success')
{
    var params =  'top=0, left=0';
    params += ', width='+screen.width+', height='+screen.height+',statusbar=no,toolbar=no, location=no,directories=no,menubar=no,resizable=no';
    params += ', scrollbars=yes, status=no, fullscreen=yes, titlebar=no';
    newwin=window.open("page_two.php","_blank",params);
    if (window.focus) {newwin.focus()}
    return false;
}

The above codes opens the php page in a new popup like window.

Now this page works fine on my local system with no error, also works on my shared godaddy server. Recently I brought a Rackspace cloud server and uploaded the same file onto it. However I also installed things like Memcached, memcache + libevent, and eAccelaretor.

My whole website is working fine. The only problem I am facing is the page stops executing after a specific line on this cloud server.

So I have the following code block that opens the connection and establishes the session through config.php page:

<?php
include("../config.php");
if(!isset($_SESSION['my_code'])){header('Location:index.php');}
?>

Then I have whole lot of html code with CSS javascript and external files (css and js only).

I am doing an echo from session on LINE 111:-

<?php echo $_SESSION['my_code']; ?>

And the above ecoz the code with no problem.

Then I have another echo on line number 175

<?php echo $_SESSION['getText1']; ?>

But after coming to this line of code page stops and no further code (html and php both) displays.

And that I can see from source code in Mozilla and Chrome that all lines till LINE 174 is loaded which I can see in Mozilla, however on Google chrome i am unable to see anything in front end but in mozilla i can see the html part in front end till 174 line number.

So I have done an extensive search on internet but nothing I could be able to find yet. The main doubt which I have is, Is it a server related error or misconfiguration or maybe I have to do a php update or maybe there is some php stuff that I need to change. I am actually clueless, its programming or server.

What i can assure is that its not the popup problem as it also wont work when I directly navigate to that page.

Does anyone faced this kind of issue. I have been with PHP since 6 years now and this is the first time I am finding such problem, however I am new to cloud servers, so I may have done some mis-configuration there. Looking for your valuable comments.

---

PROGRESS 1

Is it something related to memory stuff??

I saw this article from Jason Judge but i am really clueless on what exactly needs to be done, this is a problem which exists for sure but there is no solution prescribed, atleast I am unable to find it. Can somebody look into this, because its really life threatening

Also I feel its positively something related to APACHE or something to be done with memory or caching, because just PHP i really don't feel anything is wrong as it works fine with localhost and my Godaddy shared server, problem persists with the Rackspace cloud hosting only. What you guyz think what could be the possible issue that causing this problem?

The thing is it just fails on <?php ?> script, so if I remove this line <?php echo $_SESSION['getText1']; ?> it fails on the next <?php ?> PHP code block

---

EDITS

EDIT 1:

No errors in php log file related to sessions

EDIT 2

When I check in Google chrome Console its hows me a red cross with the file like http://myserver.com/page_two.php with page_two.php:1

and when i click on the like it takes me to the chrome network tab and displays the following information for the file:

I have the following header information:

Request URL:http://mywebsite.comm/page_two.php
Request Method:GET
Status Code:200 OK
Request Headersview source
Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Encoding:gzip,deflate,sdch
Accept-Language:en-US,en;q=0.8,hi;q=0.6,en-GB;q=0.4
AlexaToolbar-ALX_NS_PH:AlexaToolbar/alxg-3.2
Cache-Control:max-age=0
Connection:keep-alive
Cookie:PHPSESSID=i4oqva0ruaahg6gcmnsslc64e3
Host:mywebsite.com
Referer:http://mywebsite.com/page_one.php
User-Agent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36
Response Headersview source
Cache-Control:no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Connection:close
Content-Type:text/html; charset=UTF-8
Date:Mon, 16 Dec 2013 12:43:34 GMT
Expires:Thu, 19 Nov 1981 08:52:00 GMT
Pragma:no-cache
Server:Apache/2.2.15 (CentOS)
Transfer-Encoding:chunked
X-Powered-By:PHP/5.3.3

EDIT 3 - After going through the php error logs I found this weird error message which really makes no sense to me of whats wrong happening

[Tue Dec 17 13:23:09 2013] [notice] child pid 19700 exit signal Segmentation fault (11)

WHEN I DO ECHO OF THESE SESSION ON PAGE TOP IT WORKS JUST FINE. ITS NOTHING TO DO WITH SESSION, AS WHEN I JUST SIMPLY ECHO "HI" STILL IT WONT ECHO IT AND PAGE STOPS EXECUTING THERE

Answer 1

I figured this out. As I was kind of suspected with the Memcached, memcache + libevent, and eAccelaretor from start, I just uninstalled these three services and now the webpage works fine.

Now i need to figure out, out of these which one was created issues and will update my answer back.

Thanks for everyone help and support.

Answer 2

When PHP exits with segmentation fault it means there's something wrong with your PHP installation and not your code. And usually it's an extension miss-match. You need to pin point which extension it is. Or you can use gdb to debug PHP, here's how it is done.

If you find it hard to follow the debug steps, you can always roll back few steps to a state in which the error does not occur. Then adding steps forward one by one and see when the bug is introduced. All this is done much easier if you could come up with a much simpler code which reproduces the bug.