VIP + KEEPALIVED + LVS 遇到Connection Peer的问题的解决

- 先使用命令看下ipvsadm -L --timeout 看下服务器超时时间，如果设置正常在用以下方法。

## 方法一：LVS方式进行tcp转发，进而改为http方式反向代理
取消LVS方式进行tcp转发，进而改为http方式反向代理，问题即可解决。
当然，这是在业务允许使用http的情况下，如果必须使用tcp协议，那就得使用下面的方法了。

## 方法二：修改keepalived配置文件
- **Keepalived.conf**

```conf
virtual_server 192.168.20.140 55555 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    #persistence_timeout 900
    protocol TCP
    real_server 192.168.20.154 55555  {
        weight 100
        MISC_CHECK {
        misc_path "/data/shell/check_port.pl -h 192.168.20.154 -p 55555 -w 5 -c 10"
            misc_timeout 10
        }
    }
}

#将原来的TCP_CHECK方式改为 MISC_CHECK模式，将perl脚本传到指定目录下，给可执行权限。

#查看系统是否支持perl
rpm -q perl

#perl -v  可查看版本信息
```

- **check_port.pl文件**

```pl
#!/usr/bin/perl  -w
#===============================================================================
#

#         FILE:  check_port.pl

#

#        USAGE:  check_port.pl -p <port> -h <host> (-c <critical> -w <warning> -v)

#

#  DESCRIPTION:  tests to see if the port is responding and can display timing

#

#      OPTIONS:  ---

# REQUIREMENTS:  ---

#         BUGS:  ---

#        NOTES:  ---

#       AUTHOR:  Tim Pretlove

#      VERSION:  1.3

#      CREATED:  04/12/09 13:57:23

#     REVISION:  ---

#      LICENCE:  GNU

#

#       AUTHOR:  Jim Sander jim.sander@jdsmedia.net

#      VERSION:  1.2

#     MODIFIED:  10-04-2014 16:00

#         BUGS:  Socket::pack_sockaddr_in, length is 0 error for unresolvable hostnames

#        NOTES:  Fixed; now exits with '3', status UNKNOWN, and 'host lookup failed'

#

#    This program is free software: you can redistribute it and/or modify

#    it under the terms of the GNU General Public License as published by

#    the Free Software Foundation, either version 3 of the License, or

#    (at your option) any later version.

#

#    This program is distributed in the hope that it will be useful,

#    but WITHOUT ANY WARRANTY; without even the implied warranty of

#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

#    GNU General Public License for more details.

#

#    You should have received a copy of the GNU General Public License

#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

#
#===============================================================================

use strict;
use warnings;
use Socket;
use Getopt::Long;
use Time::HiRes qw(gettimeofday tv_interval);

my ($crit, $warn, $timeout, $host, $portnum, $verbose);
GetOptions(
    'crtitical=s'   => \$crit,
    'warning=s'     => \$warn,
    'timeout=s'     => \$timeout,
    'host=s'        => \$host,
    'port=s'        => \$portnum,
    'verbose'       => \$verbose) or HELP_MESSAGE();

sub testport {
	my ($host,$port,$protocol,$timeout) = @_;
    my $startsec;
    my $elapsed = 0;
	if (!defined $timeout) { $timeout = 10 }
	if (!defined $protocol) { $protocol = "tcp" }
	my $proto = getprotobyname($protocol);
	my $iaddr = inet_aton($host);
	if ( !defined $iaddr ){ return 3,$elapsed; }
	my $paddr = sockaddr_in($port, $iaddr);
	$startsec = [gettimeofday()];
	socket(SOCKET, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
	eval {
		local $SIG{ALRM} = sub { die "timeout" };
		alarm($timeout);
		connect(SOCKET, $paddr) or error();
		alarm(0);
	};
	if ($@) {
		close SOCKET || die "close: $!";
		$elapsed = tv_interval ($startsec, [gettimeofday]);
		return "1",$elapsed;
	} else {
		close SOCKET || die "close: $!";
		$elapsed = tv_interval ($startsec, [gettimeofday]);
		return "0",$elapsed;
	}
}
sub HELP_MESSAGE {
	print "$0 -p <port> -h <host> (-c <critical> -w <warning> -v)\n"; 
	print "\t -p <port> # port number to examine\n";
	print "\t -h <hostname> # hostname or ip address to contact\n";
	print "\t -c <seconds> # the number of seconds to wait before a going critical\n";
	print "\t -w <seconds> # the number of seconds to wait before a flagging a warning\n";
	print "\t -v # displays nagios performance information\n";
	print "\te.g $0 -p 80 -h www.google.com -c 1.5 -w 1.0 -v\n";
    exit(4);
}

sub printperf {
    my ($warning,$critical,$elapsed) = @_;
	if ((defined $warning) && (defined $critical)) {
		print "|rta=$elapsed" . "s;$warning;$critical;0;$critical";
	} else {
		print "|rta=$elapsed" 
	}
}

sub test {
    my ($critical,$warning,$host,$portnum,$timeout) = @_;
    my $proto = "tcp";
	my ($rc,$elapsed) = testport($host,$portnum,$proto,$timeout); 
	if ($rc == 0) {
		if (defined $critical) {
			if ($critical <= $elapsed) {
				return 2,$elapsed;
			}
		}
		if (defined $warning) {
			if ($warning <= $elapsed) {
				return 1,$elapsed;
			}
		}
		return $rc,$elapsed;
	} else {
		return 2,$elapsed;
	}
}

unless ((defined $portnum) && (defined $host)) { 
	HELP_MESSAGE();
	exit 1;
}
if ((defined $crit) && (defined $warn)) {
	if ($crit <= $warn) {
		print "Error: warning is greater than critical will never reach warning\n";
		exit 4;
	}
}

my @mess = qw(OK WARNING CRITICAL UNKNOWN);
my @mess2 = ("is responding","is slow responding","is not responding","host lookup failed");
my ($rc,$elapsed) = test($crit,$warn,$host,$portnum,$timeout);
print "PORT $portnum $mess[$rc]: $host/$portnum $mess2[$rc]";
if (defined $verbose) {
	printperf($warn,$crit,$elapsed);
}
exit($rc);
```