[리눅스] pacemaker로 nginx 고가용성(High Availability) 설정하기

pacemaker로 nginx 고가용성(High Availability) 설정하기

테스트 환경

호스트 이름	서버 아이피	도메인	운영체제	비고
VIP	192.168.0.60	vip.cluster.local
control1	192.168.0.51	control1.cluster.local	Ubuntu 22.04 LTS
node3	192.168.0.63	node3.cluster.local	Ubuntu 22.04 LTS

pcs status

$ pcs status
Cluster name: hacluster
Cluster Summary:
  * Stack: corosync
  * Current DC: node3.cluster.local (version 2.1.2-ada5c3b36e2) - partition with quorum
  * Last updated: Tue Feb  7 12:45:51 2023
  * Last change:  Tue Feb  7 11:05:49 2023 by root via cibadmin on node3.cluster.local
  * 2 nodes configured
  * 1 resource instance configured

Node List:
  * Online: [ control1.cluster.local node3.cluster.local ]

Full List of Resources:
  * VirtualIP   (ocf:heartbeat:IPaddr2):         Started control1.cluster.local

Daemon Status:
  corosync: active/enabled
  pacemaker: active/enabled
  pcsd: active/enabled

ngixn를 클러스터 리소스로 추가

cd /usr/lib/ocf/resource.d/heartbeat

wget -q https://raw.githubusercontent.com/ClusterLabs/resource-agents/master/heartbeat/nginx

chmod +x /usr/lib/ocf/resource.d/heartbeat/nginx

pcs resource agents ocf:heartbeat

$ pcs resource agents ocf:heartbeat
IPaddr2
iscsi
iSCSILogicalUnit
iSCSITarget
LVM-activate
nginx

nginx 고가용성 설정하기

nginx 설치

apt-get install -y nginx

echo '<h1>webserver 01</h1>' > /var/www/html/index.html

echo '<h1>webserver 02</h1>' > /var/www/html/index.html

systemctl restart nginx

리소스(resource) 추가

pcs resource create nginx_webserver ocf:heartbeat:nginx configfile=/etc/nginx/nginx.conf op monitor interval=30s

 pcs status resources

$ pcs status resources
  * VirtualIP   (ocf:heartbeat:IPaddr2):         Started control1.cluster.local
  * webserver   (ocf:heartbeat:nginx):   Started node3.cluster.local

클러스터 리소스 그룹

pcs constraint colocation add webserver with VirtualIP INFINITY

pcs constraint

$ pcs constraint
Location Constraints:
  Resource: VirtualIP
    Enabled on:
      Node: control1.cluster.local (score:200)
      Node: node3.cluster.local (score:100)
Ordering Constraints:
Colocation Constraints:
  webserver with VirtualIP (score:INFINITY)
Ticket Constraints:

$ pcs constraint order VirtualIP then webserver
Adding VirtualIP webserver (kind: Mandatory) (Options: first-action=start then-action=start)

$ pcs status resources                         
  * VirtualIP   (ocf:heartbeat:IPaddr2):         Started control1.cluster.local
  * webserver   (ocf:heartbeat:nginx):   Started control1.cluster.local

수동으로 리소스 이동

pcs constraint location webserver prefers node3.cluster.local=INFINITY

$ pcs status resources      
  * VirtualIP   (ocf:heartbeat:IPaddr2):         Started node3.cluster.local
  * webserver   (ocf:heartbeat:nginx):   Started node3.cluster.local

$ pcs constraint --full
Location Constraints:
  Resource: VirtualIP
    Enabled on:
      Node: control1.cluster.local (score:200) (id:location-VirtualIP-control1.cluster.local-200)
      Node: node3.cluster.local (score:100) (id:location-VirtualIP-node3.cluster.local-100)
  Resource: webserver
    Enabled on:
      Node: node3.cluster.local (score:INFINITY) (id:location-webserver-node3.cluster.local-INFINITY)
Ordering Constraints:
  start VirtualIP then start webserver (kind:Mandatory) (id:order-VirtualIP-webserver-mandatory)
Colocation Constraints:
  webserver with VirtualIP (score:INFINITY) (id:colocation-webserver-VirtualIP-INFINITY)
Ticket Constraints: