ASIC/FPGA Design and Verification Out Source Services

A perl script to monitor a linux OS operation.

1. A few days ago, this site fell for a few hours. It was the result of some bandwidth consuming commands, which I mistakenly run, from remote.
   The "dieing" process was slow. Probably the swap was increasingly used and load average value became high.


2. Should I have rebooted the system, the shut down period would have been short. Or better, should a script to monitor some of the system parameters be existed, it could have been done automatically.


3. Such a perl script is under development. It, presently monitors the swap size as well as swap data in and data out rate in KB/sec, number of active processes on the system and load average.
   


4. The code of the script is shown below:
   
   #!/bin/perl
   
   open(FPW, ">>/home/pini/junk/Pini/sys_mon.txt") || die("open fail $o_name\n");
   
   $flg=1;
   while($flg == 1) {
     $dateS=`date +%y%m%d_%H%M%S`; chomp($dateS);
   
     #swap size
     $cmd="free | grep Swap";
     $r=`$cmd`;
     chomp($r);
     $r =~ s/Swap://;
     $r =~ s/ ([0-9])/_\1/g;
     $r =~ s/ //g;
     $r =~ s/_/ /g;
     $r =~ s/^ //g;
     @a=split(/ /, $r);
     #total used free
     $used_p=($a[1]*100)/$a[0];
     $used_p=int($used_p);
     if($used_p > 75) {
       chomp($used_p);
       $flg=0;#quit and re-boot
       #also check swap in and out KB/sec
       $r=`vmstat`;
       @a=split(/\n/, $r);
       $a[2] =~ s/ *([0-9]*)/_\1/g;
       @aa=split(/_/, $a[2]);
       $si=$aa[7];
       $so=$aa[8];
       while( length($si) < 4 ) {$si=" " . $si;}
       while( length($so) < 4 ) {$so=" " . $so;}
       #common print
       print FPW ("$dateS swap $used_p si=$si so=$so\n");
     }
   
     #load average
     $cmd="cat /proc/loadavg";
     $r=`$cmd`;
     chomp($r);
     @a=split(/ /, $r);
     #1min 5min 15min
     if($a[0] > 10 && $a[1] > 5) {
       chomp($a[0]); chomp($a[1]);
       print FPW ("$dateS load average $a[0] $a[1]\n");
       $flg=0;#quit and re-boot
     }
   
     #number of active processes
     $cmd="ps -aef | wc -l";
     $r=`$cmd`;
     chomp($r);
     if($r > 800) {
       print FPW ("$dateS number of active processes on the system $r\n");
       $flg=0;#quit and re-boot
     }
     sleep(120);
   
   }#while
   
   close(FPW);
   #shutdown -r now
   

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