Keepalived is a routing software written in C. The main goal of this project is to provide simple and robust facilities for loadbalancing and high-availability to Linux system and Linux based infrastructures. Loadbalancing framework relies on well-known and widely used Linux Virtual Server (IPVS)<\/a> kernel module providing Layer4 loadbalancing. Keepalived implements a set of checkers to dynamically and adaptively maintain and manage loadbalanced server pool according their health. On the other hand high-availability is achieved by VRRP<\/a> protocol. VRRP is a fundamental brick for router failover. In addition, Keepalived implements a set of hooks to the VRRP finite state machine providing low-level and high-speed protocol interactions. In order to offer fastest network failure detection, Keepalived implements BFD<\/a> protocol. VRRP state transition can take into account BFD hint to drive fast state transition. Keepalived frameworks can be used independently or all together to provide resilient infrastructures.<\/p>\n\n\n\n As always, start with installint the software:<\/p>\n\n\n\n Now, move original configuration file and create you own and insert values like below. This is configuration for primary (master) server1:<\/p>\n\n\n\n Save and close the file when you are finished.<\/p>\n\n\n\n On the secondary (slave) server2, edit the keepalived.conf file, very similar to our first:<\/p>\n\n\n\n Now we will need to create a script to check whether the apache service is running or not. You can create it using the following command:<\/p>\n\n\n\n Now we set proper permission with the following command:<\/p>\n\n\n\n Before we start keeplived daemon, if we have (I believe, you have) firewall enabled, enable vrrp protocol:<\/p>\n\n\n\n Finally, start keepalived service and enable it to start at system reboot using the following command.<\/p>\n\n\n\n We can also check the status of keepalived service using the following command:<\/p>\n\n\n\n What is Keepalived ? Keepalived is a routing software written in C. The main goal of this project is to provide simple and robust facilities for loadbalancing and high-availability to Linux system and Linux based infrastructures. Loadbalancing framework relies on well-known and widely used Linux Virtual Server (IPVS) kernel module providing Layer4 loadbalancing. Keepalived implements … Continue reading Centos 9 and keeplived<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[149,94,151,152],"class_list":["post-1033","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-centos-9","tag-httpd","tag-keeplived","tag-vrrp"],"_links":{"self":[{"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=\/wp\/v2\/posts\/1033","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1033"}],"version-history":[{"count":1,"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=\/wp\/v2\/posts\/1033\/revisions"}],"predecessor-version":[{"id":1034,"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=\/wp\/v2\/posts\/1033\/revisions\/1034"}],"wp:attachment":[{"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1033"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1033"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gonscak.sk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1033"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}dnf install keepalived -y<\/pre>\n\n\n\n
mv \/etc\/keepalived\/keepalived.conf \/etc\/keepalived\/keepalived.conf.original
vim \/etc\/keepalived\/keepalived.conf
global_defs {
# Keepalived process identifier
router_id apache
}
# Script to check whether apache is running or not
vrrp_script check_httpd {
script \"\/bin\/check_httpd.sh\"
interval 2
weight 50
}
# Virtual interface - The priority specifies the order in which the assigned interface to take over in a failover
vrrp_instance apache {
state MASTER
interface ens18
virtual_router_id 151
priority 110
# The virtual ip address shared between the two apache Web Servers which will float
virtual_ipaddress {
192.168.1.10\/24
}
track_script {
check_httpd
}
authentication {
auth_type PASS
auth_pass secret
}
}<\/pre>\n\n\n\nmv \/etc\/keepalived\/keepalived.conf \/etc\/keepalived\/keepalived.conf.original
vim \/etc\/keepalived\/keepalived.conf
global_defs {
# Keepalived process identifier
router_id apache
}
# Script to check whether apache is running or not
vrrp_script check_httpd {
script \"\/bin\/check_httpd.sh\"
interval 2
weight 50
}
# Virtual interface - The priority specifies the order in which the assigned interface to take over in a failover
vrrp_instance apache {
state BACKUP
interface ens18
virtual_router_id 151
priority 100
# The virtual ip address shared between the two apache Web Servers which will float
virtual_ipaddress {
192.168.1.10\/24
}
track_script {
check_httpd
}
authentication {
auth_type PASS
auth_pass secret
}
}<\/pre>\n\n\n\nvim \/bin\/check_httpd.sh
#!\/bin\/sh
if [ -z \"`pidof httpd`\" ]; then
exit 1
fi<\/pre>\n\n\n\nchmod 755 \/bin\/check_httpd.sh<\/pre>\n\n\n\n
firewall-cmd --add-protocol=vrrp --permanent
firewall-cmd --add-protocol=vrrp<\/pre>\n\n\n\nsystemctl enable keepalived --now<\/pre>\n\n\n\n
systemctl status keepalived<\/pre>\n ","protected":false},"excerpt":{"rendered":"