$_SESSION variable go crazy and no pattern to debug

issamo

ok I have three pages of code:

1 page go to second then go to third and I can go back....but sometimes I enter values in the first page go to second and enter another values ..then next to display the final values ..it displays them right for the first time.....then if I go back and do a fix and come back to the final page I see the old values and not the new ones......sometimes it work sometimes it doesnt...its so random and very hard to debug and see where is my problem........I put for u the code for each page:

page 1:

<?

session_start();

if($_POST['Action']){

$IP_FQDNAddress = $POST["IP_FQDNAddress"];
$Row['IP_FQDN'] = $IP_FQDNAddress;
$CPU_Type = $POST["CPUType"];
$Row['CPU'] = $CPU_Type;
$OS_Type = $POST["OSList"];
$Row['OS'] = $OS_Type;
$Memory_Type = $POST["MemType"];
$Row['Memory'] = $Memory_Type;
$Disk_Space = $POST["DiskSpace"];
$Row['Space'] = $Disk_Space;
$Emergency_Contact = $POST["Emergency"];
$Row['Emergency'] = $Emergency_Contact;
$Server_Type = $POST["ServerType"];
$Row['ServerType']=$Server_Type;
$SESSION['IP_FQDN'] = $IP_FQDNAddress;
$SESSION['CPU']= $CPU_Type;
$SESSION['OS'] = $OS_Type;
$SESSION['Memory'] = $Memory_Type;
$SESSION['Space'] = $Disk_Space;
$SESSION['Emergency'] = $Emergency_Contact;
$SESSION['ServerType']= $Server_Type;

  $_SESSION['FQDN'] = $IP_FQDNAddress;
  $_SESSION['IP'] = $IP_FQDNAddress);
  session_write_close();
  header("Location: http://somesite/page2.php");

}
}

}

if($_GET['Back1']==1){

$GET['CPU'] = $SESSION['CPU'];
$GET['OS'] = $SESSION['OS'];
$GET['Memory'] = $SESSION['Memory'];
$GET['Space']= $SESSION['Space'];
$GET['Emergency'] = $SESSION['Emergency'];
$GET['ServerType']= $SESSION['ServerType'];

$Row['IP_FQDN'] = $SESSION['IP_FQDN'];
$Row['CPU'] = $SESSION['CPU'];
$Row['OS'] = $SESSION['OS'];
$Row['Memory'] = $SESSION['Memory'];
$Row['Space']= $SESSION['Space'];
$Row['Emergency'] = $SESSION['Emergency'];
$Row['ServerType']= $SESSION['ServerType'];
$GET['Back1']=0;
}

<html>
<head>
<title>Add Server Form</title>
</head>
<style></style>

<? } ?>

<body>
<form method="POST">
<table>
<tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b

Server IP/FQDN Name :</b></td>
<td><input type="text" name="IP_FQDNAddress" value=<?echo $Row['IP_FQDN']?>></td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b>Server Type :</b></td>
<td>
<select name="ServerType">

<option value="">Select a Type
<option value="SAV"<?=$Row['ServerType']=="SAV"?" selected":NULL?>>SAV
<option value="WSUS"<?=$Row['ServerType']=="WSUS"?" selected":NULL?>>WSUS
<option value="SAV&WSUS"<?=$Row['ServerType']=="SAV&WSUS"?" selected":NULL?>>SAV&WSUS
</select>
</td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b
CPU Type :</b></td>
<td>
<select name="CPUType">
<option value="">Select a Type
<option value="Intel"<?=$Row['CPU']=="Intel"?" selected":NULL?>>Intel
<option value="AMD"<?=$Row['CPU']=="AMD"?" selected":NULL?>>AMD
</select>
</td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b
OS Type :</b></td>
<td>
<select name="OSList">
<option value="">Select a Type
<option value="Win2000"<?=$Row['OS']=="Win2000"?" selected":NULL?>>Win2000
<option value="Win2003"<?=$Row['OS']=="Win2003"?" selected":NULL?>>Win2003
<option value="WinXP"<?=$Row['OS']=="WinXP"?" selected":NULL?>>WinXP
<option value="Unix"<?=$Row['OS']=="Unix"?" selected":NULL?>>Unix
</select>
</td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b
Memory Type :</b></td>
<td>
<select name="MemType">
<option value="">Select a Type
<option value="SRAM"<?=$Row['Memory']=="SRAM"?" selected":NULL?>>SRAM
<option value="DRAM"<?=$Row['Memory']=="DRAM"?" selected":NULL?>>DRAM
</select>
</td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b
Disk Space (in G😎 :</b></td>
<td><input type="text" name="DiskSpace" value=<?echo $Row['Space']?>></td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b
Emergency Contact :</b></td>
<td>
<textarea name="Emergency"><?echo $Row['Emergency']?></textarea>
</td>
</tr><tr>
<td><input type="submit" name="Action" value="Next">
<input type="submit" name="Clear" value="Clear"></td>
</tr>
</table>
</form>
<hr>

</body>
</html>

page 2:
<?
require_once "libs/dbdefs.php";
require_once "libs/functions.php";

session_start();

if($_POST['Action']){

$SESSION['LabName'] = $POST["LabName"];
$SESSION['LabLinkType'] = $POST["LabLinkType"];
$SESSION['ServerLinkType'] = $POST["ServerLinkType"];

$Row['LabName'] = $SESSION['LabName'];
$Row['LabLinkType'] = $SESSION['LabLinkType'];
$Row['ServerLinkType'] = $_SESSION['ServerLinkType'];
session_write_close();
header("Location: http://somesite/page3.php");

}

if($_GET['Back2']==1){

$Row['LabName'] = $SESSION['LabName'];
$Row['ServerLinkType'] = $SESSION['ServerLinkType'];
$Row['LabLinkType'] = $SESSION['LabLinkType'];
echo $SESSION['IP'];
echo $SESSION['Space'];
echo $SESSION['Emergency'];
echo "spacing--";
$_GET['Back2']=0;

}

<html>

<title>Add Server-Lab Form</title>
</head>
<style></style>

<body>
<form method="POST">
<table>
<tr>
<td Style="font-size:14; background-color:Lightblue; text-align: left"><b

Server IP/FQDN:</b></td>
<td>
<select name="ServerIP_FQDN">
<option><? echo $_SESSION['IP_FQDN']. " (New Server)" ?></option>
</select>
</td>

</tr><tr>

   <td style="font-size:14; background-color:Lightblue; text-align: left"><b

Server Type used in this Lab:</b></td>
<td>
<select name="ServerLinkType">
<option value="">Select a Type
<option value="SAV"<?=$Row['ServerLinkType']=="SAV"?" selected":NULL?>>SAV
<option value="WSUS"<?=$Row['ServerLinkType']=="WSUS"?" selected":NULL?>>WSUS
<option value="SAV&WSUS"<?=$Row['ServerLinkType']=="SAV&WSUS"?" selected":NULL?>>SAV&WSUS
</select>
</td>
</tr><tr>
<td style="font-size:14; background-color:Lightblue; text-align: left"><b
Server Location: </b></td>
<td>
<select name="LabLinkType">
<option value="">Select a Type
<option value="InsideLab"<?=$Row['LabLinkType']=="InsideLab"?" selected":NULL?>>Inside the Lab
<option value="External"<?=$Row['LabLinkType']=="External"?" selected":NULL?>>External
</select>
</td>
</tr><tr>
<td><input type="submit" name="Action" value="Submit">
<input type="submit" name="Clear" value="Clear"</td>
</tr>

</table>
</form>

<hr> 
<a href="http://somesite/page1.php?Back1=1">Go back</a>

<?
echo $SESSION['IP'];
echo $SESSION['Space'];
echo $_SESSION['Emergency'];

</body>

</html>

page 3:
<?

require_once "libs/dbdefs.php";
require_once "libs/functions.php";

session_start();

if($_POST['Action'])
{

echo "start";

}
?>

<html>
<head>
<title>New Server Confirmation Form</title>
</head>
<body>

<h2><font color="blue">Adding New Server Summary: </font></h2>
<p><font color="blue"><b>Server IP: </b><?echo $SESSION['IP']?></font></p>
<p><font color="blue"><b>Server FQDN: </b><?echo $SESSION['FQDN']?></font></p>
<p><font color="blue"><b>Server Supported Type(s): </b><?echo $SESSION['ServerType']?></font></p>
<p><font color="blue"><b>Server CPU Type: </b><?echo $SESSION['CPU']?></font></p>
<p><font color="blue"><b>Server Operating System Type: </b><?echo $SESSION['OS']?></font></p>
<p><font color="blue"><b>Server Memory Type: </b><?echo $SESSION['Memory']?></font></p>
<p><font color="blue"><b>Server Disk Space in GB: </b><?echo $SESSION['Space']?></font></p>
<p><font color="blue"><b>Emergency Contact Process: </b><?echo $SESSION['Emergency']?></font></p>
<p><font color="blue"><b>Lab Name using this New Server: </b><?echo $SESSION['LabName'
]?></font></p>
<p><font color="blue"><b>New Server Type(s) used for this Lab: </b><?echo $SESSION['ServerLinkType']?></font></p>
<p><font color="blue"><b>New Server location: </b><?echo $_SESSION['LabLinkType']?></font></p>

</body>
</html>

I spent days on thsi problem..🙁

any hint would be helpful,
Issamo

etully

Is it possible that the pages are coming from your web browser's cache? You should hit reload or shift reload and that might refresh the page.

Are you sure you're posting to a page? The <form> tags don't have an action telling it which page to go to. Form tags should be in the form:

If you're not posting to a page, then maybe the new values aren't getting assigned to session?

Roger_Ramjet

Your problem is definitely cache control, it always is with dynamic content. What you need to do is to include the following header code at the top of every php page you code.

<?php
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
session_start();
header("Cache-Control: private");

Most people make a header.php file that they include as the first line of each page that has dynamic content. You would also generally include the rest of your standard head stuff as well.

NB the above code must be the very first thing in the file and must be sent to the client before any other html output whatsoever - even whitespace.

issamo

thanks guys for the tips..however still the problem occurs...I found out that I call a list of clusters of servers which explains why I get old values from time to time since the cash is not up to date in every server....now trying to figure out how can I solve this issue..🙁..any tips would ..

etully

Well, there are two solutions:

Stop using session and use cookies instead. This way, the customer's computer announces all of its values on every web request.
Let PHP store the session cookie on the user's computer but only maintain that data on Web Server #1. Whenever anyone connects to Web server #2-n, they pass the session id on to server #1 and find the current values (or write new values).

So in general, there are two solutions. In practice, there are probably a dozen ways to implement the second solution. If any of the experts in this forum know where I can do some reading about suggested ways to implement a FAST, RELIABLE, SAFE, and STABLE shared session across multiple servers, this is something I'd like really like to know more about.