Linking IBMi data to a Gauge in PHP

We were thinking about how to create a new interface for one of our old utilities using PHP and decided that using a JavaScript based gauge would probably be a good start. There are plenty of free and chargeable JavaScript utilities out there that would do what we wanted, the one we settled on was a HTML5 Canvas implementation developed by Mykhailo Stadnyk. He has placed the code on the web and agreed to anyone running the code under a MIT license which basically allows you to copy and use the code where ever you want. If you would like to use the code it is available here, simply copy the javascript file into your directory structure and include.

We made a couple changes to the javascript code as it calls a remote HTTP server to pull back a font so we found a substitute font and installed it on the PC. There are a couple of examples available which can be used to demonstrate the gauge in action which again we used as the basis for our test. The only other point we should mention is that the demo does rely on HTML5 and canvas, if it is not supported in your browser the test will not work!

The method used to get the data from the IBMi is to call a Service Program through the i5_program_call available in the Aura i5_toolkit. Below is the C Program to return the information, it just calls the QWCRSSTS API and returns the Pct_Processing_Unit_Used value as can be seen in the code below.


#include <stdio.h> /* Standard I/O */
#include <stdlib.h> /* Standard library */
#include <string.h> /* String handlers */
#include <qusec.h> /* Error Code */
#include <errno.h> /* Error Num Conversion */
#include <decimal.h> /* Decimal support */
#include <qusec.h> /* Error Code */
#include <qwcrssts.h> /* System Status */
#pragma comment(copyright,"Copyright @ Shield Advanced Solutions Ltd 1998-2001")

typedef _Packed struct EC_x{
Qus_EC_t EC;
char Exception_Data[1024];
} EC_t;

int Get_Svr_Status(char *CPU_Util,char *reset) {
double Cpu_Pct;
char Reset[10] = "*NO "; /* Reset CPU % */
Qwc_SSTS0200_t Buf; /* System Status Struct */
EC_t Error_Code = {0}; /* Error Code Struct */

Error_Code.EC.Bytes_Provided = sizeof(Error_Code);
// reset the CPU Utilization?
if(*reset == 'Y')
memcpy(Reset,"*YES ",10);
QWCRSSTS(&Buf,
sizeof(Buf),
"SSTS0200",
Reset,
&Error_Code);
if(Error_Code.EC.Bytes_Available > 0) {
sprintf(CPU_Util,"99999");
return -1;
}
// Just set up the CPU Utilization here
Cpu_Pct = (double)Buf.Pct_Processing_Unit_Used / 10;
sprintf(CPU_Util,"%f",Cpu_Pct);
return 1;
}

The web page is generated using the following code.


<?php
/*
Copyright © 2010, Shield Advanced Solutions Ltd
All rights reserved.

http://www.shieldadvanced.ca/

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

- Neither the name of the Shield Advanced Solutions, nor the names of its
contributors may be used to endorse or promote products
derived from this software without specific prior written
permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

*/
// start the session to allow session variables to be stored and addressed
session_start();
require_once("scripts/functions.php");
// load up the config data
if(!isset($_SESSION['server'])) {
load_config();
}
$conn = 0;
$_SESSION['conn_type'] = 'non_encrypted';
if(!connect($conn)) {
if(isset($_SESSION['Err_Msg'])) {
echo($_SESSION['Err_Msg']);
$_SESSION['Err_Msg'] = "";
}
echo("Failed to connect");
}
// get the information
get_cpu_util($conn);
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html style="width:100%;height:100%">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Gauge Test</title>
<script src="jscripts/gauge.js"></script>
<style>body{padding:0;margin:0;background:#222}</style>
</head>
<body style="width:100%;height:100%">
<canvas id="gauge"></canvas>
<div id="console"></div>
<script>
var gauge = new Gauge({
renderTo : 'gauge',
width : document.body.offsetWidth,
height : document.body.offsetHeight,
glow : true,
units : 'Cpu Utilization',
title : false,
minValue : 0,
maxValue : 110,
majorTicks : ['0','10','20','30','40','50','60','70','80','90','100','110'],
minorTicks : 2,
strokeTicks : false,
highlights : [
{ from : 0, to : 50, color : 'rgba(240, 230, 140, .25)' },
{ from : 50, to : 70, color : 'rgba(255, 215, 0, .45)' },
{ from : 70, to : 90, color : 'rgba(255, 165, 0, .65)' },
{ from : 90, to : 100, color : 'rgba(255, 0, 0, .85)' },
{ from : 100, to : 110, color : 'rgba(178, 34, 34, .99)' }
],
colors : {
plate : '#fff',
majorTicks : '#f5f5f5',
minorTicks : '#ddd',
title : '#fff',
units : '#0bb',
numbers : '#0aa',
needle : { start : 'rgba(240, 128, 128, 1)', end : 'rgba(255, 160, 122, .9)' }
}
});
gauge.onready = function() {
gauge.setValue( <?php echo($_SESSION['CPU_Util']); ?> );
};

gauge.draw();

window.onresize= function() {
gauge.updateConfig({
width : document.body.offsetWidth,
height : document.body.offsetHeight
});
};
</script>
<?php ?>
</html>

To call the Service Program we created a function ‘get_cpu_util()’ which is called every time the page is refreshed. Here is the code for the get_cpu_util function.


function get_cpu_util($conn) {
$desc = array (array ("Name" => "CPU_Util", "io" => I5_INOUT, "type" => I5_TYPE_CHAR, "length" => "5"),
array ("Name" => "Reset_Status", "io" => I5_IN, "type" => I5_TYPE_CHAR, "length" => "1") );
$prog = i5_program_prepare("PHPTSTSRV(Get_Svr_Status)", $desc,$conn);
if ($prog == FALSE) {
$errorTab = i5_error ();
echo "Program prepare failed Display_Server_Status <br>";
var_dump($errorTab);
var_dump($conn);
die ();
}
$parmOut = array("CPU_Util" => "cpu_util");
$parameter = array("CPU_UTIL" => "", "Reset_Status" => "N");
$ret = i5_program_call($prog, $parameter, $parmOut);
if (!$ret) {
throw_error("i5_program_call failed Retrieve_Status <br>");
exit();
}
// close the program call
i5_program_close($prog);
$_SESSION['CPU_Util'] = $cpu_util;

return 1;
}

The majority of the work is done in the Javascript section above with just the data extraction from the IBMi being carried out using the i5_toolkit. We have used the same connection function that we used in our other tests but instead of asking for the profile and password we added it to the config file so no sign on screen is presented before the connection is made.

The above code resulted in the following output on our systems. The actual CPU utilization differs because it is near impossible to request the page and refresh the 5250 screen at the same time. We also noticed that the returned value is always greater than the actual value shown in the WRKACTJOB screens, but the test was more about showing the gauge working using IBMi data than ensuring we saw the same data in both interfaces.

5250 Work with Active Jobs

5250 Work with Active Jobs

Gauge showing CPU Utilization %

Gauge showing CPU Utilization %

We feel this is where modernization of the IBMi and its applications should begin, making simple tools and utilities that use the IBMi data and display it in a web based interface means you can access those interfaces from many devices. We only show the output in a PC based browser but with some simple CSS and checking code you could make sure it is correctly displayed on most devices.

Happy PHP’ing.

Chris..

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