Shulou(Shulou.com)06/03 Report--

Cluster a) A group of computing groups that are interconnected by the network and managed in a single system mode b) centralize many servers to provide the same service To the client, it looks as if there is only one server c) at a lower cost to achieve performance, reliability, D) Task scheduling is the core technology in the cluster system 1) improve performance 2) reduce cost 3) improve scalability 4) enhance reliability load balancing cluster (LB) LVS and Haproxy high availability cluster (HA) keepalived and RHCSLVS application cluster deployment NAT mode [client role] 192.168.2.253 CIP: client IP 192. 168.2.50 VIP: load balancer IP (IP providing virtual services) [dispenser] 192.168.4.50 DIP: interact with RIP (IP forwarded out requests) 192.168.4.51 [website server] RIP: real server IP 192.168.4.52 how it works: when a user requests The destination IP is VIP, the source IP is CIP, and then it reaches the VIP. The dispenser converts its destination IP to RIP, and its source IP remains unchanged, and then DIP transmits it to the back-end server. When the back-end server processes the response, the source IP is RIP, and the destination IP is CIP, which is passed to DIP, and the source IP is modified to VIP through the dispenser. Then send it back to the CIP client through the VIP network card a) turn on the route forwarding function # / etc/sysctl.confsed-I'7s' sed'/ etc/sysctl/conf#sysctl-p to make it effective immediately b) install the software package ipvsadmyum-y install ipvsadm...c) specify the gateway address [client] # route add default gw 192.168.2.50 / sed-I'$aGAETWAY=192.168.2.50' / etc/sysconfig/ Network-scripe/ifc-eth0 [website server] # route add default gw 192.168.4.50d) add virtual service # ipvsadm-A-t 192.168.2.50 rr 80-E modify scheduling algorithm specify virtual server polling mode # ipvsadm-a-t 192.168.2.50 rr 80-r 192.168.4.51 ipvsadm 80-m-e modification mode Virtual server address real server address nat mode # ipvsadm-a-t 192.168.2.50 cat 80-r 192.168.4.52 cat 80-m#service ipvsadm save save the above configuration # cat / etc/sysconfig/ipvsadm#ipvsadm-ln-stats view configuration information # watch-D1 ipvsadm-ln-stats real-time monitoring deployment DR mode [client role] 192.168.4.253 CIP: client IP 192.168.4.252 VIP: IP of load balancer (IP providing virtual services) [dispenser] 192.168.4.50 DIP: interacting with RIP (IP forwarding requests) 192.168.4.51 192.168.4.252 [website server] RIP: real server IP VIP 192.168.4.52 192.168.4.252 how it works: add a VIP address to the lo port of the back-end web server When the target IP of the request is VIP, it will not add VIP to the dispatcher in response to the message. When the user requests it, it will send it to the RIP through the dispenser. After the RIP receives the message, it uses the VIP on the lo port to return the packet. [website server 51amp 52] add VIP address And do not respond to the message ifconfig lo:1 192.168.4.252 change / proc/sys/net/ipv4/conf/lo/echo 1 > arp_ignore arp_ignore: define the response mode for receiving arp requests echo 2 > arp_announce arp_announce: define notification mode modification / proc/sys/net/ipv4/conf/all/echo 1 > arp_ignoreecho 2 > arp_announce [dispenser] add VIP address ifconfig eth0:1 192.168 .4.252x32 unbind: # service network restart#ipvsadm-A-t 192.168.4.252 rr#ipvsadm 80-a-t 192.168.4.252 service network restart#ipvsadm 80-r 192.168.4.51 The default is DR mode # ipvsadm-a-t 192.168.4.252 service ipvsadm save#watch 80-r 192.168.4.52 service ipvsadm save#watch-d 1 ipvsadm-ln-stats

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