/ipvs scheduling algorithm for LVS load Balancing implementation mechanism

Eight kinds of scheduling algorithms:
: rr|wrr|lc|wlc|lblc|dh|sh|
Wheel call scheduling (Round-robin scheduling)
Weighted wheel call scheduling (weighted Round-robin scheduling)
Minimum connection scheduling (Least-connection scheduling)
Weighted minimum connection scheduling (weighted least-connection scheduling)
Minimal links based on locality (locality-based least connections scheduling)
Local least-link with replication (locality-based least connections with Replication scheduling)
Target Address hash dispatch (destination hashing scheduling)
Source Address hash dispatch (hashing scheduling)

Three kinds of equilibrium mechanisms:

IP load Balancing technology is the most efficient in the implementation of the load scheduler.

The three mechanisms were:

Virtual server via network address translation (Vs/nat): There is also a port map that aims to make a group of servers a high-performance, highly available virtual server. Because this technology is easy to form a single point of failure, which makes the network inaccessible, and there are bandwidth bottlenecks. So LVS provides the following two kinds of implementations.

Virtual Server via IP tunneling (vs/tun): Virtualization services are implemented via IP tunneling.

Virtual server via direct Routing (VS/DR): A way to implement virtual servers directly (with the highest load capacity), this article builds DR mode.

Lvs

When using keepalived to do LVS, the real server (real-server) needs to write a script for ipvsadm alone, Windows needs to loop back to the network interface, and when Ipvsadm is enabled and working, Keepalived will take over control Ipvsadm.

Script:

The code is as follows

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#!/bin/bash vip=192.168.2.130 /etc/rc.d/init.d/functions Case "$" in Start Ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP /sbin/route add-host $VIP Dev lo:0 echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce Sysctl-p >/dev/null 2>&1 echo "Realserver Start OK" ;; Stop Ifconfig lo:0 Down Route del $VIP >/dev/null 2>&1 echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce echo "Realserver stoped" ;; *) echo "Usage: $ {start|stop}" Exit 1 Esac Exit 0

Ipvsadm

Ipvsadm-l

Ipvsadm-ln

Ipvsadm-lnc

Vrrp_script Configuration

The code is as follows

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Vrrp_script Chk_sshd { Script "killall-0 sshd" # cheaper than pidof Interval 2 # Check every 2 seconds Weight-4 # Default Prio:-4 if KO # weight-40 # if failed, decrease of the priority Fall 1 # require 2 failures for failures Rise 1 # require 1 sucesses for OK } Vrrp_script Chk_haproxy { Script "killall-0 haproxy" # cheaper than pidof Interval 2 # Check every 2 seconds } Vrrp_script Chk_http_port { #script "/TCP/127.0.0.1/80" # Connects and exits #script "Nc-z 127.0.0.1" # Connects and exits Script "</TCP/127.0.0.1/80" # Connects and exits Interval 1 # Check every second Weight-2 # Default Prio:-2 if Connect fails } Vrrp_script Chk_https_port { Script "/tcp/127.0.0.1/443" Interval 1 Weight-2 } Vrrp_script Chk_smtp_port { Script "/TCP/127.0.0.1/25" Interval 1 Weight-2 } Vrrp_instance Vi_1 { Interface eth0 State MASTER VIRTUAL_ROUTER_ID 51 Priority 100 virtual_ipaddress { 192.168.200.18/25 } Track_interface { eth1 Weight 2 # prio = +2 if up Eth2 weight-2 # prio =-2 if down Eth3 # no weight, fault if down } Track_script { CHK_SSHD # Use default weight the script Chk_haproxy Weight 2 # +2 If process is present Chk_http_port Chk_https_port Chk_smtp_port } } Vrrp_instance Vi_2 { Interface eth1 State MASTER VIRTUAL_ROUTER_ID 52 Priority 100 virtual_ipaddress { 192.168.201.18/26 } Track_interface { Eth0 Weight 2 # prio = +2 if up Eth2 weight-2 # prio =-2 if down Eth3 # no weight, fault if down } Track_script { Chk_haproxy Weight 2 Chk_http_port Chk_https_port Chk_smtp_port } }

One example configuration:

The code is as follows

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! Configuration File for Keepalived Global_defs { Notification_email { notify@aooshi.org } Notification_email_from servername@aooshi.org Smtp_server 192.168.2.111 Smtp_connect_timeout 30 router_id webcache253-keepalived } Vrrp_script Check_http { Script "</DEV/TCP/127.0.0.1/80" Interval 5 Weight-10 } Vrrp_instance vi_158 {     State BACKUP     interface eth0   & nbsp VIRTUAL_ROUTER_ID     Priority     advert_int 1     SMTP _alert     Authentication {         Auth_type pass         auth_pass webcache    }     virtual_ipaddress {         192.168.2.158 brd 192.168.2.255 label eth0:158    }  track_script {   check_http   } Vrrp_instance vi_159 {     State MASTER     interface eth0   & nbsp VIRTUAL_ROUTER_ID     Priority     advert_int 1     Smtp_alert     Authentication {         Auth_type pass         auth_pass webcache    }     virtual_ipaddress {         192.168.2.159 brd 192.168.2.255 label eth0:159    }  track_script {   check_http   }