lvs+keepalived Implement Ha

High Availability ha

Highavailable

1, the need heartbeat mechanism to detect whether the back-end RS provide services.

A) detection down, need to remove the RS from LVs

B probe send from down to up, need to add RS again from LVS.

2, Lvs DR, need to master (HA)

Keepalived: Provides highly available

VRRP protocol to realize the drift of IP

Zookeeper:

The difference between keepalived and zookeeper is that master hangs up, and when Master is back up, it can take over. keepalived Installation:

At least two servers need to be installed

Yuminstall keepalived

keepalived configuration file

At least two servers

1. Address:/etc/keepalived/keepalived.conf

2, help manual: Mankeepalived.conf

3, before editing, need to back up: cp–akeepalived.conf Keepalived.conf.bak

4. Edit:

! Configuration File for Keepalived

Global_defs {

Notification_email {

root@localhost# send a reminder message can have more than one destination address

Goldbin@126.com

}

Notification_email_from root@localhost# send the From address of the mail, can write at will, the email address does not exist does not matter

Smtp_server 127.0.0.1# Mail Service address, general write local

Smtp_connect_timeout 30

router_id Lvs_devel

}

Vrrp_instance Vi_1 {

State BACKUP #MASTER Lord and from

Interface Eth0 #VIP需要绑定的网卡名称

VIRTUAL_ROUTER_ID 51

Priority 101# Priority Master priority is at least higher than from 50, master 101 from <=50

Advert_int 1

Authentication {

Auth_type Pass

Auth_pass 1111

}

virtual_ipaddress {

192.168.223.100/24 Dev eth0 label eth0:0 #设置VIP

}

}

Virtual_server 192.168.223.100 {#设置虚拟lvs服务, VIP PORT

Delay_loop 6

Lb_algo rr# Scheduling Algorithm WRR

The pattern of Lb_kind Dr#lvs

Nat_mask 255.255.255.0

Persistence_timeout 50 The same IP address in 50 seconds LVs forward to the same back-end server

Protocol TCP

Real_server 192.168.223.111 {#设置真实服务器的心跳机制 RID PORT

Weight weight

Http_get {#心跳检测的方式

URL {

path/#心跳检查的地址

Status_code 200# The status returned by the heartbeat check

}

Connect_timeout 2 #超时时间

Nb_get_retry 3# repeat Check 3 times

Delay_before_retry, check again every 1 seconds.

}

}

Real_server 192.168.223.112 {#第二个真实服务器设置

Weight 1

Http_get {

URL {

Path/

Status_code 200

}

Connect_timeout 2

Nb_get_retry 3

Delay_before_retry 1

}

}

}

keepalived Startup and Logging

Service keepalived Start

Tail/var/log/message View the log.

Install mail:yum–y Install Mail

Turn off a real server's Tomcat:killall Java

To view messages on the Lvs_master machine: Mail

Thinking:

1, Nginx +keepalived high availability (do not need LVS).