$VAR1 = [
          {
            'eventid' => '957',
            'name' => 'aaaa'  
          },
          {
            'eventid' => '2667',
            'name' => 'bbbb'
          },
          {
            'eventid' => '2667'
            'name' => 'bbbb'
          },
          {
            'eventid' => '1503'
            'name' => 'cccc'
          },
          {
            'eventid' => '1103'
            'name' => 'dddd'
          },
          {
            'eventid' => '1503'
            'name' => 'cccc'
          }
        ];

##</code><code>##

#!/usr/bin/env perl       
use strict;
use warnings;
use XML::XPath;
use Data::Dumper;

my $xml = 'ApplicationList.xml';
my $xp = XML::XPath->new(filename => $xml);
my $appxpath =  $xp->findnodes("//application_list/application/");

my %appid = ();
foreach my $appnodeset ($appxpath->get_nodelist) {
  my $id   = $xp->find('./@id',$appnodeset)->string_value;
  my $name = $xp->find('./@name',$appnodeset)->string_value;
  s/^\s+|\s+$//g for $id,$name;
  $appid{$id} = $name;
}
print Dumper \%appid;

my $eventxml = 'events.xml';
my $evenxp = XML::XPath->new(filename => $eventxml);
my $xpath = "//event/custom_attribute_list/custom_attribute[normalize-space(name)='SLB_SSRID']/value";

my @eventrecords = ();
foreach my $node ($evenxp->findnodes($xpath)) { 
  my $ssrid = $node->string_value;
  $ssrid =~ s/^\s+|\s+$//g ;
  if ( exists $appid{$ssrid} ){
    push @eventrecords, 
      { eventid => $ssrid };
  } 
}
print Dumper \@eventrecords;