Using a Browser to Display System Performance

Using a Browser to Display System Performance

Audience: All

Date: November 25, 2002

Here's a quick and easy method for displaying a system's performance from a PC browser. The following chart illustrates CPU performance, but you can display any data collected by "sar" command: disk usage, run queues, paging, etc.

The procedure to set this up is as follows:

Enable HTTP on your server. See your system documentation
Enable "sar" to collect performance data. The following steps enable sar data collection on a 15 minute interval, from midnight to midnight, Monday-Friday. Customize to your needs.
- login as root
- Switch to the adm user id
  # su - adm
- Add the following crontab entry:
  # crontab -e
  0 * * * 1-5 /usr/lib/sa/sa1 900 4 &
Install "gnuplot" (http://www-1.ibm.com/servers/aix/products/aixos/linux/download.html )
Edit sarplot.cgi (below) to point to the "gnuplot" program

Copy sarplot.cgi to the CGI directory

        # On my system, it look like this
        cp sarplot.cgi   /usr/HTTPServer/cgi-bin
        chmod a+x /usr/HTTPServer/cgi-bin/sarplot.cgi

Copy sarplot.htm to the HTTP document directory

        # On my system, it looks like
        cp sarplot.htm  /usr/HTTPServer/htdocs
        chmod a+r /usr/HTTPServer/htdocs/sarplot.htm

Point your browser to http://yourhostname/sarplot.htm

sarplot.htm


<html>
<head><h2>Performance Measures:</h2></head>
<body>
<FORM ACTION="cgi-bin/sarplot.cgi" METHOD="POST">
<TABLE WIDTH=500 BORDER=0 CELLSPACING=0 CELLPADDING=5 
BGCOLOR="#BBBBBB">
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="u" CHECKED> 
</TD>
  <TD> cpu usage </TD>
 </TR>
 <TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="d" CHECKED> 
</TD>
  <TD> disk usage </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="b"> </TD>
  <TD> buffer activity </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="y"> </TD>
  <TD> TTY device activity </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="c"> </TD>
  <TD> system calls </TD>
 </TR>
<TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="w"> </TD>
  <TD> swapping and switching </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="a"> </TD>
  <TD> file access statistics </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="q"> </TD>
  <TD> run queue statistics </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="v"> </TD>
  <TD> process, inode and file tables </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="m"> </TD>
  <TD> message and semaphore activity </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="p"> </TD>
  <TD> paging (-p) </TD>
 </TR>
<TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="g"> </TD>

  <TD> paging (-g) </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="r"> </TD>
  <TD> unused memory pages and disk blocks </TD>
 </TR>
 <TR>
  <TD ALIGN=CENTER> <INPUT TYPE="RADIO" NAME="opt" VALUE="k"> </TD>
  <TD> kernel memory allocation </TD>
 </TR>
 <TR>
  <TD>
   <INPUT TYPE="SUBMIT" VALUE="GRAPH IT!">
  </TD>
  <TD>
   After making your selection, click the button
  </TD>
 </TR>
</TABLE>
</body>

sarplot.htm


#!/usr/bin/perl
# sarplot.cgi, shs 11/14/02, plot sar data
# modified by Bruce Sepncer, 11/25/02 
# 	added section for  disk usage 
#	changed tif to gif
#	added yrange 0 to 100 for CPU, Disk and run queues

####################### Your Customizations go here #############
# Location of the gnuplot command
my $gnuplot = "/usr/local/bin/gnuplot";

####################### End of Your Customizations ##############


# ---------------------------------------------------------- modules
use IPC::Open3;
use CGI qw(:standard);

# ------------------------------------------------------- parameters
$opt=param('opt');
if ( ! $opt =~ /\w/ ) {		# replace if not single letter
    $opt="u";
}

# Set YRange on plot
# Found that gnuplot didn't do it properly
if ( $opt =~ /u|d|q/ ) {
	$YRANGE = "[ 0 to 100 ]";
	} else {
	$YRANGE = "[ 0 to 1000 ]";
	}

$dt=`date`;		 	# save date for title

chomp($dt);
@sarstats=`sar -$opt`;		 # capture data from sar
$data="/tmp/stats$$";		 # identify temp file

# ----------------------------------------------- process sar output
open DATA, ">$data" or die "Cannot open $data for writing";

foreach $line (@sarstats) {

    if ( $line =~ /Average/ ) {
		last;
    } elsif ( $line =~ /^$/ ) {
	next; # skip blank lines

    } elsif ( $opt eq "d" ) {

    	if    ( $line=~/^\d+:\d+:\d+.+hdisk/ ) { # first line in reading
		@cols=split(/\s+/, $line);  
		$disk_line= $cols[0] . " " . $cols[3];
		}
	elsif ( $line =~ /hdisk/ ) {
		@cols=split(/\s+/, $line);  
		$disk_line .= " " . $cols[2];
		} 	
	elsif ( $line =~ /cd/ ) {
		print DATA ("$disk_line \n");
		}
	
    } elsif ( $line=~/\d+:\d+:\d+.+[a-z]/ ) { # capture column headings

        @hdgs=split ' ',$line;		 # store in array for later use

    } else  {
		 print DATA "$line";
    }
}
close DATA;

# Because the "sar -d" provides multi lines, must read headings differently
# 
if ( $opt eq "d" ) {
	
	@hdgs="";
 	foreach $line (@sarstats) {

		if ( $line =~ /cd/ ) { last; }
		if ( $line =~ /hdisk\d+/ ) {
			@hdgs= (@hdgs, $&);
			}
	} # end for each

} # end if

$sz=$#hdgs;		 # number of data columns

# ------------------------------------------------------ run gnuplot
$| = 1;		 	 # disable buffering

my $pid = open3(\*GNUPLOT, \*GRAPHDATA, \*ERROR, $gnuplot);

# send commands to gnuplot
print GNUPLOT << "END";
set term gif color
set title "$dt (sar -$opt)";
set timefmt "%H:%M"
set xdata time
set format x "%H:%M"
set xtics border rotate
set xrange ["00:00" to "23:59"]
set yrange $YRANGE
END

# send command line for each data column
print GNUPLOT "plot ";
for ($x=2; $x<=$sz; $x++) {
    $h=$x-1;
    print GNUPLOT "'$data' using 1:$x t '$hdgs[$h]' with line,";
}
# last line is separate because is has no continuation character
print GNUPLOT "'$data' using 1:$x t '$hdgs[$x-1]' with line";

close(GNUPLOT);

# identify data type
print header("image/gif");

# send the image back to the browser
while ($length = sysread(GRAPHDATA,$content,1024)) {
		 syswrite(STDOUT,$content,$length);
}

close(GRAPHDATA);

`/usr/bin/rm $data`;

Bruce Spencer,
baspence@us.ibm.com