PaceMaker + corosync in Centos6
LPIC304の勉強として。 PaceMakerはCentos7で使ったことあるのですが、Centos6のPaceMakerはあまり経験がないので構築してみました。 VIPとhttpdリソースを使って、VIPにアクセスするとWebが表示されるような構成です。
構成
| ホスト名 | IP | VIP |
|---|---|---|
| centos6-1 | 192.168.0.102 | 192.168.0.100 |
| centos6-2 | 192.168.0.156 |
インストール
yum -y install pacemaker # crmコマンドをインストール wget -P /etc/yum.repos.d/ http://download.opensuse.org/repositories/network:ha-clustering:Stable/RedHat_RHEL-6/network:ha-clustering:Stable.repo yum -y install crmsh
認証設定
両ノードとも以下の設定を行い、内容を揃える。
vi /etc/ha.d/authkeys auth 1 1 sha1 secret chmod 600 /etc/ha.d/authkeys
コンフィグ設定
今回はcloudStackで建てたサーバーを使う。CloudStackはマルチキャストが使えないので、udpuの方を使います。
記法は古い形式の member という記法を使います。新しいと node という記法になるらしい。
https://qiita.com/tukiyo3/items/162e131007365fc4fe80
# cp /etc/corosync/corosync.conf.example.udpu /etc/corosync/corosync.conf
# vi /etc/corosync/corosync.conf
# cat /etc/corosync/corosync.conf
# Please read the corosync.conf.5 manual page
compatibility: whitetank
aisexec {
user: root
group: root
}
service {
name: pacemaker
ver: 0
use_mgmtd: yes
}
totem {
version: 2
secauth: off
interface {
member {
memberaddr: 192.168.0.102
}
member {
memberaddr: 192.168.0.156
}
ringnumber: 0
bindnetaddr: 192.168.0.0
mcastport: 5405
ttl: 1
}
transport: udpu
}
logging {
fileline: off
to_logfile: yes
to_syslog: yes
logfile: /var/log/cluster/corosync.log
debug: off
timestamp: on
logger_subsys {
subsys: AMF
debug: off
}
}
ログのパーミッション変更とサービス起動
両方のノードで行う。
chown -R hacluster. /var/log/cluster /etc/rc.d/init.d/corosync start
確認
crm_mon コマンドは -1 をつけないと更新型の表示になる、 -1 をつけると一度きりの表示。
[root@centos6-1 ~]# crm_mon -1 Stack: classic openais (with plugin) Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum Last updated: Sat Jul 25 21:51:34 2020 Last change: Sat Jul 25 18:53:23 2020 by hacluster via crmd on centos6-2 2 nodes configured (2 expected votes) 0 resources configured Online: [ centos6-1 centos6-2 ] No active resources [root@centos6-1 ~]# crm status Stack: classic openais (with plugin) Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum Last updated: Sat Jul 25 22:01:49 2020 Last change: Sat Jul 25 18:53:23 2020 by hacluster via crmd on centos6-2 2 nodes configured (2 expected votes) 0 resources configured Online: [ centos6-1 centos6-2 ] No resources
初期設定・リソース設定
# STONITH無効化 crm configure property \ stonith-enabled=false # quorum無効化 (ノードの数が半分以下になったときはクラスタとしてサービス提供不可と見なすが2台構成で1台落ちたらその状態になるので無効化) crm configure property \ no-quorum-policy=ignore # ノード復帰時に自動でリソースを元のノード上に移そうとするのを止める crm configure rsc_defaults \ resource-stickiness=100
設定確認
[root@centos6-1 ~]# crm configure show
node centos6-1
node centos6-2
property cib-bootstrap-options: \
have-watchdog=false \
dc-version=1.1.18-3.el6-bfe4e80420 \
cluster-infrastructure="classic openais (with plugin)" \
expected-quorum-votes=2 \
stonith-enabled=false \
no-quorum-policy=ignore
rsc_defaults rsc-options: \
resource-stickiness=100
VIPの設定
# crm configure primitive vip ocf:heartbeat:IPaddr2 \
params ip="192.168.0.100" \
nic="eth0” \
cidr_netmask="24" \
op start interval="0s" timeout="60s" \
op monitor interval="5s" timeout="20s" \
op stop interval="0s" timeout="60s"
# crm configure show
node centos6-1
node centos6-2
primitive vip IPaddr2 \
params ip=192.168.0.100 nic=eth0 cidr_netmask=24 \
op start interval=0s timeout=60s \
op monitor interval=5s timeout=20s \
op stop interval=0s timeout=60s
property cib-bootstrap-options: \
have-watchdog=false \
dc-version=1.1.18-3.el6-bfe4e80420 \
cluster-infrastructure="classic openais (with plugin)" \
expected-quorum-votes=2 \
stonith-enabled=false \
no-quorum-policy=ignore
rsc_defaults rsc-options: \
resource-stickiness=100
VIPがついたことを確認
[root@centos6-1 ~]# ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
inet 192.168.0.102/24 brd 192.168.0.255 scope global eth0
inet 192.168.0.100/24 brd 192.168.0.255 scope global secondary eth0
ここでいったん設定確認
[root@centos6-1 ~]# crm_mon -1 Stack: classic openais (with plugin) Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum Last updated: Sat Jul 25 22:19:00 2020 Last change: Sat Jul 25 22:17:13 2020 by root via cibadmin on centos6-1 2 nodes configured (2 expected votes) 1 resource configured Online: [ centos6-1 centos6-2 ] Active resources: vip (ocf::heartbeat:IPaddr2): Started centos6-1
httpd設定
両方のサーバーで設定します
コンフィグ設定
vi /etc/httpd/conf/httpd.conf # 921-926行目：コメント解除しアクセス許可範囲変更 <Location /server-status> SetHandler server-status Order deny,allow Deny from all Allow from 127.0.0.1 10.0.0.0/24 </Location>
httpdのリソース設定と同居設定
crm configure primitive httpd ocf:heartbeat:apache \ params configfile="/etc/httpd/conf/httpd.conf" \ port="80" \ op start interval="0s" timeout="60s" \ op monitor interval="5s" timeout="20s" \ op stop interval="0s" timeout="60s"
同居設定
crm configure colocation coloc_1 inf: vip httpd
同居設定しない場合はグループ化でも良い
crm configure group webserver vip httpd
確認(グループ化した場合)
[root@centos6-1 ~]# crm status
Stack: classic openais (with plugin)
Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum
Last updated: Sat Jul 25 22:28:32 2020
Last change: Sat Jul 25 22:28:17 2020 by hacluster via cibadmin on centos6-2
2 nodes configured (2 expected votes)
2 resources configured
Online: [ centos6-1 centos6-2 ]
Full list of resources:
Resource Group: webserver
vip (ocf::heartbeat:IPaddr2): Started centos6-1
httpd (ocf::heartbeat:apache): Started centos6-1
Failed Actions:
* httpd_monitor_0 on centos6-1 'unknown error' (1): call=12, status=complete, exitreason='',
last-rc-change='Sat Jul 25 22:24:16 2020', queued=0ms, exec=102ms
[root@centos6-1 ~]# crm configure show
node centos6-1
node centos6-2
primitive httpd apache \
params configfile="/etc/httpd/conf/httpd.conf" port=80 \
op start interval=0s timeout=60s \
op monitor interval=5s timeout=20s \
op stop interval=0s timeout=60s
primitive vip IPaddr2 \
params ip=192.168.0.100 nic=eth0 cidr_netmask=24 \
op start interval=0s timeout=60s \
op monitor interval=5s timeout=20s \
op stop interval=0s timeout=60s
group webserver vip httpd
property cib-bootstrap-options: \
have-watchdog=false \
dc-version=1.1.18-3.el6-bfe4e80420 \
cluster-infrastructure="classic openais (with plugin)" \
expected-quorum-votes=2 \
stonith-enabled=false \
no-quorum-policy=ignore
rsc_defaults rsc-options: \
resource-stickiness=100
アクセスしてみる
グローバルIPにアクセスするとこんな感じです。
メンテナンスモードにする
クラスタ全体をメンテナンスモードにします。httpdサービス自体は継続されます。
[root@centos6-1 ~]# crm configure property maintenance-mode=true
[root@centos6-1 ~]# crm status
Stack: classic openais (with plugin)
Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum
Last updated: Sat Jul 25 22:57:31 2020
Last change: Sat Jul 25 22:57:28 2020 by root via cibadmin on centos6-1
2 nodes configured (2 expected votes)
2 resources configured
*** Resource management is DISABLED ***
The cluster will not attempt to start, stop or recover services
Online: [ centos6-1 centos6-2 ]
Full list of resources:
Resource Group: webserver
vip (ocf::heartbeat:IPaddr2): Started centos6-1 (unmanaged)
httpd (ocf::heartbeat:apache): Started centos6-1 (unmanaged)
Failed Actions:
* httpd_monitor_0 on centos6-1 'unknown error' (1): call=12, status=complete, exitreason='',
last-rc-change='Sat Jul 25 22:24:16 2020', queued=0ms, exec=102ms
[root@centos6-1 ~]# ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
inet 192.168.0.102/24 brd 192.168.0.255 scope global eth0
inet 192.168.0.100/24 brd 192.168.0.255 scope global secondary eth0
メンテナンスモードを解除します。
[root@centos6-1 ~]# crm configure property maintenance-mode=false
[root@centos6-1 ~]#
[root@centos6-1 ~]# crm status
Stack: classic openais (with plugin)
Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum
Last updated: Sat Jul 25 22:58:49 2020
Last change: Sat Jul 25 22:58:45 2020 by root via cibadmin on centos6-1
2 nodes configured (2 expected votes)
2 resources configured
Online: [ centos6-1 centos6-2 ]
Full list of resources:
Resource Group: webserver
vip (ocf::heartbeat:IPaddr2): Started centos6-1
httpd (ocf::heartbeat:apache): Started centos6-1
Failed Actions:
* httpd_monitor_0 on centos6-1 'unknown error' (1): call=12, status=complete, exitreason='',
last-rc-change='Sat Jul 25 22:24:16 2020', queued=0ms, exec=102ms
フェイルオーバーしてみる
フェイルオーバーしてみます。現在centos6-1というサーバーにリソースがあるので、centos6-2に移します。現在リソースがあるノードに対して、 crm node stanby [node_name] でフェイルオーバーされます。
[root@centos6-1 ~]# crm node standby centos6-1
[root@centos6-1 ~]# crm status
Stack: classic openais (with plugin)
Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum
Last updated: Sat Jul 25 23:01:02 2020
Last change: Sat Jul 25 23:01:00 2020 by root via crm_attribute on centos6-1
2 nodes configured (2 expected votes)
2 resources configured
Node centos6-1: standby
Online: [ centos6-2 ]
Full list of resources:
Resource Group: webserver
vip (ocf::heartbeat:IPaddr2): Started centos6-2
httpd (ocf::heartbeat:apache): Started centos6-2
Failed Actions:
* httpd_monitor_0 on centos6-1 'unknown error' (1): call=12, status=complete, exitreason='',
last-rc-change='Sat Jul 25 22:24:16 2020', queued=0ms, exec=102ms
IPはcentos6-2に移動したことがわかりました。
[root@centos6-2 ~]# ip -4 a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
inet 192.168.0.156/24 brd 192.168.0.255 scope global eth0
inet 192.168.0.100/24 brd 192.168.0.255 scope global secondary eth0
Webはこんな感じです。
スタンバイ状態から復旧させます。復旧させても、リソースはcentos6-2のままです。
[root@centos6-1 ~]# crm node online centos6-1
[root@centos6-1 ~]# crm status
Stack: classic openais (with plugin)
Current DC: centos6-2 (version 1.1.18-3.el6-bfe4e80420) - partition with quorum
Last updated: Sat Jul 25 23:01:42 2020
Last change: Sat Jul 25 23:01:39 2020 by hacluster via crm_attribute on centos6-2
2 nodes configured (2 expected votes)
2 resources configured
Online: [ centos6-1 centos6-2 ]
Full list of resources:
Resource Group: webserver
vip (ocf::heartbeat:IPaddr2): Started centos6-2
httpd (ocf::heartbeat:apache): Started centos6-2
Failed Actions:
* httpd_monitor_0 on centos6-1 'unknown error' (1): call=12, status=complete, exitreason='',
last-rc-change='Sat Jul 25 22:24:16 2020', queued=0ms, exec=102ms
