Global load balance between two servers (failover), with no preemption

This is another version of the perl script, that adds a feature that make sure that the backup server is out-of-the-manual resume at all time.

 

 

!/usr/bin/perl

 

 

================================================================

 

Description: Enable pool members that are manually disabled when their pool

 

is completely down, due to a manual resume feature.

 

Combining this with global availability, to Globally failover between two servers will

 

prevent possible flapping issues, if one of the servers goes unstable.

 

================================================================

 

Disclaimer:

 

This script is provided "AS IS", for non-commercial use, and you, its user, assume all risks when using it.

 

================================================================

 

 

 

use strict;

 

use warnings;

 

 

define system commands

 

my $snmpwalk_prog = '/usr/bin/snmpwalk -v2c -c baltimore localhost ';

 

my $pool_status = $snmpwalk_prog . 'gtmPoolStatusAvailState';

 

my $pool_member_order = $snmpwalk_prog . 'gtmPoolMbrOrder';

 

my $pool_member_enabled = $snmpwalk_prog . 'gtmPoolMbrEnabled';

 

my %pools;

 

 

get pool member order

 

open( my $pool_member_order_out, '-|', $pool_member_order )

 

or die "Failed to run command $pool_member_order : $!";

 

while (<$pool_member_order_out>) {

 

my ( $pool, $member ) = / "(.*?)" [.]ipv4[.] "(.*?)" /x;

 

my ($member_order) = / (\d) $ /x;

 

$pools{$pool}{MEMBER}{$member} = $member_order;

 

}

 

 

get pool member enable status

 

open( my $pool_member_enabled_out, '-|', $pool_member_enabled )

 

or die "Failed to run command $pool_member_enabled : $!";

 

while (<$pool_member_enabled_out>) {

 

my ( $pool, $member ) = / "(.*?)" [.]ipv4[.] "(.*?)" /x;

 

my ($status) = / INTEGER: \s+ ( enable | disable ) /x;

 

my $member_order = $pools{$pool}{MEMBER}{$member};

 

$pools{$pool}{$member_order} = $status;

 

}

 

 

get pool status

 

open( my $pool_status_out, '-|', $pool_status )

 

or die "Failed to run command $pool_status : $!";

 

while (<$pool_status_out>) {

 

 

get pool

 

my ($pool) = /"(.*?)"/;

 

 

pool status

 

my ($pool_status) = / INTEGER: \s+ ( green | red ) /x;

 

 

pool status is red or member 1 is disabled

 

if ( ( $pool_status eq 'red' )

 

or ( exists $pools{$pool}{1} and $pools{$pool}{1} eq 'disable' ) )

 

{

 

construct command

 

my $cmd =

 

"tmsh modify gtm pool $pool members modify { all { enabled }}";

 

 

run command

 

print "Running command: $cmd\n";

 

system($cmd) == 0 or die "$cmd failed";

 

}

 

}