Keepalived provides health checks for RealServers and failover between LoadBalance hosts.keepalived to in , a service , can implement in node or node , and can in ipvshas node node , node node Master/Backup.
VRRP (easily understood if you know TCP/IP):
(VRRP) is , can a to VRRP . IP Address VRRP , data to these IP Address. not can , process provide , IP Addresscan . use VRRP is has can in each configuration or . VRRP in IP .
VRRP:
VRRPeach node is has , is from 0-255 , can : to has status , node 100 node 99, , is node all node all is backupstatus , via method master, if node no will master : if between nodes master, , we manage already keepalivedsupport , if status can via method manage , manage can view status ,
keepalivedpart
- vrrp implement
- virtual_server: vrrp
- vrrp_script:method perform
keepalived
KeepAlived Installation:
[root@Nginx-one ~]# tar zxf keepalived-1.2.13.tar.gz [root@Nginx-one ~]# cd keepalived-1.2.13[root@Nginx-one keepalived-1.2.13]# yum install kernel-devel openssl-devel libnl-devel[root@Nginx-one keepalived-1.2.13]# ./configure --prefix=/ --mandir=/usr/local/share/man/ --with-kernel-dir=/usr/src/kernels/2.6.32-431.el6.x86_64/[root@Nginx-one keepalived-1.2.13]# make && make installKeepalived configuration------------------------Keepalived version : 1.2.13 ##version#Compiler : gcc ##tool ##Compiler flags : -g -O2 ####Extra Lib : -lssl -lcrypto -lcrypt ####Use IPVS Framework : Yes ##LVS, not use LVScan disable-lvs##IPVS sync daemon support : Yes ##IPVS, is IPVS FRAMEWORK###IPVS use libnl : Yes ##is use libnl##fwmark socket support : Yes ####Use VRRP Framework : Yes ##VRRP, keepalived vrrpd##Use VRRP VMAC : Yes ##VRRP Virtual mac##SNMP support : NoSHA1 support : NoUse Debug flags : No[root@Nginx-one keepalived-1.2.13]# make && make install
KeepAlived all configuration all in a configuration file setting , support configuration can the following :
1, configuration (global configure) 2, VRRPDconfiguration 3, LVSconfiguration , configuration is for keepalived configuration , not is use LVS, VRRPDis keepalived , LVSconfiguration in to use keepalivedconfiguration and manage LVSuse , if use keepalivedHA, LVSnot need configuration . configuration file all is (block) , each all in {}, # and !.
(global definition)
global_defs { notification_email { ##keepalivedin () need Email for , ## itchenyi@gmail.com } notification_email_from itchenyi@gmail.com smtp_server 127.0.0.1 ##SMTPserver ## smtp_connect_timeout 30 #### router_id Nginx-one ##, ##}
VRRPDconfiguration (VRRP (syncchroization group) and VRRP (VRRP instance) )
not use SYNC Group , if has 2, a , a , each a VRRP, VRRPconfiguration , Issues , VRRPDis , not Master and Backup , from Issues, Sync Groupcan all Sync Group, , Group a Issuesall .
vrrp_instance VI_1 { ####state MASTER ##status , , can Master , Master##interface eth1 ##via ##virtual_router_id 10 ## ID, not 255, can IPuse ##priority 100 ##, process , and ##advert_int 1 ##, 1s##authentication { ####auth_type PASS ##method , PASS##auth_pass ipython ####}virtual_ipaddress { ##Address##1.1.1.100}}### configuration ###
configuration Backup configuration :
[root@nginx-two keepalived-1.2.13]# cat /software/keepalived/etc/keepalived/keepalived.conf ! Configuration File for keepalivedglobal_defs { notification_email { itchenyi@gmail.com } notification_email_from itchenyi@gmail.com smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id nginx-two}vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 20 priority 50 advert_int 1 authentication { auth_type PASS auth_pass ipython } virtual_ipaddress { 1.1.1.100 }}###configuration : #### nopreempt setting not , this configuration can setting in stateBACKUP node , and this preempt_delay , 5 debug debug notify_master to Master Script##start##[root@Nginx-one keepalived-1.2.13]# service keepalived startStarting keepalived: [ OK ]###file ###[root@Nginx-one keepalived-1.2.13]# tail -f /var/log/messages Aug 3 00:02:12 Nginx-one Keepalived[8177]: Starting Keepalived v1.2.13 (08/03,2014)Aug 3 00:02:12 Nginx-one Keepalived[8178]: Starting Healthcheck child process, pid=8180Aug 3 00:02:12 Nginx-one Keepalived[8178]: Starting VRRP child process, pid=8181#### IPAddress####Aug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Netlink reflector reports IP 1.1.1.10 addedAug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Netlink reflector reports IP fe80::20c:29ff:fecb:90a2 addedAug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Registering Kernel netlink reflectorAug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Registering Kernel netlink command channelAug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Netlink reflector reports IP 1.1.1.10 addedAug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Netlink reflector reports IP fe80::20c:29ff:fecb:90a2 addedAug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Registering Kernel netlink reflectorAug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Registering gratuitous ARP shared channelAug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Registering Kernel netlink command channelAug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Opening file '/etc/keepalived/keepalived.conf'.Aug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Configuration is using : 62834 BytesAug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: Using LinkWatch kernel netlink reflector...Aug 3 00:02:13 Nginx-one Keepalived_vrrp[8181]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]###configuration file ####Aug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Opening file '/etc/keepalived/keepalived.conf'.Aug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Configuration is using : 7377 BytesAug 3 00:02:13 Nginx-one Keepalived_healthcheckers[8180]: Using LinkWatch kernel netlink reflector...####Master status ####Aug 3 00:02:14 Nginx-one Keepalived_vrrp[8181]: VRRP_Instance(VI_1) Transition to MASTER STATEAug 3 00:02:15 Nginx-one Keepalived_vrrp[8181]: VRRP_Instance(VI_1) Entering MASTER STATEAug 3 00:02:15 Nginx-one Keepalived_vrrp[8181]: VRRP_Instance(VI_1) setting protocol VIPs.####in VIP###Aug 3 00:02:15 Nginx-one Keepalived_vrrp[8181]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 1.1.1.100Aug 3 00:02:15 Nginx-one Keepalived_healthcheckers[8180]: Netlink reflector reports IP 1.1.1.100 addedAug 3 00:02:20 Nginx-one Keepalived_vrrp[8181]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 1.1.1.100###view is VIP###[root@Nginx-one keepalived-1.2.13]# ip a show|awk '/inet/ /' inet 127.0.0.1/8 scope host lo inet 1.1.1.10/8 brd 1.255.255.255 scope global eth1 inet 1.1.1.100/32 scope global eth1StopMASTER, view BACKUP status [root@Nginx-one keepalived-1.2.13]# service keepalived stopStopping keepalived: [ OK ][root@nginx-two keepalived-1.2.13]# tail -f /var/log/messages Aug 3 00:05:01 nginx-two Keepalived_vrrp[5148]: Using LinkWatch kernel netlink reflector...Aug 3 00:05:01 nginx-two Keepalived_vrrp[5148]: VRRP_Instance(VI_1) Entering BACKUP STATEAug 3 00:05:01 nginx-two Keepalived_healthcheckers[5147]: Using LinkWatch kernel netlink reflector...Aug 3 00:05:01 nginx-two Keepalived_vrrp[5148]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]Aug 3 00:05:40 nginx-two Keepalived_vrrp[5148]: VRRP_Instance(VI_1) Transition to MASTER STATEAug 3 00:05:41 nginx-two Keepalived_vrrp[5148]: VRRP_Instance(VI_1) Entering MASTER STATEAug 3 00:05:41 nginx-two Keepalived_vrrp[5148]: VRRP_Instance(VI_1) setting protocol VIPs.Aug 3 00:05:41 nginx-two Keepalived_healthcheckers[5147]: Netlink reflector reports IP 1.1.1.100 addedAug 3 00:05:41 nginx-two Keepalived_vrrp[5148]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 1.1.1.100Aug 3 00:05:46 nginx-two Keepalived_vrrp[5148]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 1.1.1.100#### and , MASTERto VIP, can to , Keepalivedsupport , has BACKUPin MASTER, VIP, ####
Keepalived
### nginx is in ###[root@nginx-two ~]# cat nginx_check.sh #!/bin/bashalive=`netstat -pant|awk '/0.0.0.0:80/&&/LISTEN/'|wc -l`if [ $alive -eq 1 ]; then exit 0else exit 1fi###keepalivedconfiguration ###vrrp_script nginx_check{ script "/root/nginx_check.sh" interval 1 ### 1s### weigh -60 ###if , -60###}####will track_scriptinstance configuration #### track_script { nginx_check }[root@Nginx-one ~]# service keepalived restartStopping keepalived: [ OK ]Starting keepalived: [ OK ]###, to nginx 80is , is ###[root@Nginx-one ~]# ip a show|awk '/inet/ /' inet 127.0.0.1/8 scope host lo inet 1.1.1.10/8 brd 1.255.255.255 scope global eth1 inet 1.1.1.100/32 scope global eth1###Nginxservice ###[root@Nginx-one ~]# service nginx stopStopping nginx: [ OK ]Aug 3 00:52:13 Nginx-one Keepalived_vrrp[8490]: VRRP_Script(nginx_check) failedAug 3 00:52:14 Nginx-one Keepalived_vrrp[8490]: VRRP_Instance(VI_1) Entering FAULT STATEAug 3 00:52:14 Nginx-one Keepalived_vrrp[8490]: VRRP_Instance(VI_1) removing protocol VIPs.Aug 3 00:52:14 Nginx-one Keepalived_vrrp[8490]: VRRP_Instance(VI_1) Now in FAULT stateAug 3 00:52:14 Nginx-one Keepalived_healthcheckers[8489]: Netlink reflector reports IP 1.1.1.100 removed###BackupMaster###[root@nginx-two ~]# ip a show|awk '/inet/ /' inet 127.0.0.1/8 scope host lo inet 1.1.1.20/8 brd 1.255.255.255 scope global eth1 inet 1.1.1.100/32 scope global eth1
Original http://www.ipython.me/centos/keepalived-config-using.html