[Devmon-devel] Speeding up exception processing

[W.J.M. N. <Wim...@nl...>]

Hello,

the patch below disables capturing of fields when evaluating the 
'except' directive. This directive is taken from the DEVMON tag in the 
hosts.cfg file of Xymon (bb-hosts file in case of Hobbit). It decreases 
the CPU utilization and lowers the Devmon run-time.

In our environment, Devmon is run in single-node mode, with 15 childs, 
on a HP DL 380, dual CPU with two cores each. Devmon checks 777 devices, 
and for 95 of them an 'except' directive is used. (Most of those devices 
are Cisco switches. 'Except' is used to ignore the interfaces which are 
disabled.) Using the patch below, the run-time of Devmon has decreased 
with about 1.4 [s], and the CPU utilization has decreased with 2%.

The patch on Devmon r216 is:

Index: dm_tests.pm
===================================================================
--- dm_tests.pm (revision 37)
+++ dm_tests.pm (working copy)
@@ -1848,12 +1848,12 @@
           my $a_val  = $dev->{'except'}{$test}{$pri}{'alarm'}     ||
             $dev->{'except'}{'all'}{$pri}{'alarm'}                ||
             $tmpl->{'oids'}{$pri}{'except'}{'alarm'};
-          $alarm = ($pri_val =~ /^($a_val)$/) ? 1 : 0  if defined $a_val;
+          $alarm = ($pri_val =~ /^(?:$a_val)$/) ? 1 : 0  if defined $a_val;
 
           my $na_val = $dev->{'except'}{$test}{$pri}{'noalarm'}   ||
             $dev->{'except'}{'all'}{$pri}{'noalarm'}              ||
             $tmpl->{'oids'}{$pri}{'except'}{'noalarm'};
-          $alarm = 0 if defined $na_val and $pri_val =~ /^($na_val)$/;
+          $alarm = 0 if defined $na_val and $pri_val =~ /^(?:$na_val)$/;
 
          # Now go through all the oids in our table row and replace them
           for my $root ($row_data =~ /\{(.+?)}/g) {
@@ -1881,8 +1881,8 @@
             my $only = $dev->{'except'}{$test}{$oid}{'only'}     ||
               $dev->{'except'}{'all'}{$oid}{'only'}              ||
               $tmpl->{'oids'}{$oid}{'except'}{'only'};
-            next T_LEAF if defined $ignore and $val =~ /^($ignore)$/;
-            next T_LEAF if defined $only and $val !~ /^($only)$/;
+            next T_LEAF if defined $ignore and $val =~ /^(?:$ignore)$/;
+            next T_LEAF if defined $only and $val !~ /^(?:$only)$/;
 
 
            # If we arent alarming on a value, its green by default
@@ -2210,28 +2210,28 @@
 
     if(defined $dev->{'except'}{$test}{$oid}{'noalarm'}) {
       my $match = $dev->{'except'}{$test}{$oid}{'noalarm'};
-      return 1 if $val =~ /^($match)$/;
+      return 1 if $val =~ /^(?:$match)$/;
     }
     elsif(defined $dev->{'except'}{'all'}{$oid}{'noalarm'}) {
       my $match = $dev->{'except'}{'all'}{$oid}{'noalarm'};
-      return 1 if $val =~ /^($match)$/;
+      return 1 if $val =~ /^(?:$match)$/;
     }
     elsif(defined $tmpl->{'oids'}{$oid}{'except'}{'noalarm'}) {
       my $match = $tmpl->{'oids'}{$oid}{'except'}{'noalarm'};
-      return 1 if $val =~ /^($match)$/;
+      return 1 if $val =~ /^(?:$match)$/;
     }
 
     if(defined $dev->{'except'}{$test}{$oid}{'alarm'}) {
       my $match = $dev->{'except'}{$test}{$oid}{'alarm'};
-      return 1 if $val !~ /^($match)$/;
+      return 1 if $val !~ /^(?:$match)$/;
     }
     elsif(defined $dev->{'except'}{'all'}{$oid}{'alarm'}) {
       my $match = $dev->{'except'}{'all'}{$oid}{'alarm'};
-      return 1 if $val !~ /^($match)$/;
+      return 1 if $val !~ /^(?:$match)$/;
     }
     elsif(defined $tmpl->{'oids'}{$oid}{'except'}{'alarm'}) {
       my $match = $tmpl->{'oids'}{$oid}{'except'}{'alarm'};
-      return 1 if $val !~ /^($match)$/;
+      return 1 if $val !~ /^(?:$match)$/;
     }
   }

Kind regards,
  Wim Nelis.




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