Pacemaker+Corosync+DRBD实现Openstack A/P高可用

本文是基于CentOS 7及Openstack juno版本的高可用实践。

高可用组件安装配置

准备工作

首先确保两台机器时间同步，配置ssh。

安装组件

添加yum源，这个源包含了crmsh、resource-agents等包：

[haclustering]
name=HA Clustering
baseurl=http://download.opensuse.org/repositories/network:/ha-clustering:/Stable/CentOS_CentOS-7/
enabled=1
gpgcheck=0

安装相关组件：

#yum install pacemaker corosync resource-agents crmsh pcs

安装DRBD

方法一通过yum源安装：

# rpm --import http://elrepo.org/RPM-GPG-KEY-elrepo.org
# rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm
# yum -y install drbd84-utils kmod-drbd84

方法二编译安装：

#yum install docbook-style-xsl          #编译drbd时候用到
#mkdir -p /tmp/drbdinst
#/usr/bin/wget --directory-prefix=/tmp/drbdinst/ http://oss.linbit.com/drbd/8.4/drbd-8.4.5.tar.gz
#cd /tmp/drbdinst
#tar -zxfp drbd-8.4.5.tar.gz
#cd drbd-8.4.5
#/usr/bin/yum -y install flex gcc make
#make
#make install
#/usr/bin/yum -y install libxslt
#/usr/bin/wget --directory-prefix=/tmp/drbdinst/ http://oss.linbit.com/drbd/drbd-utils-8.9.1.tar.gz
#cd /tmp/drbdinst
#tar -zxfp drbd-utils-8.9.1.tar.gz
#cd drbd-utils-8.9.1
#./configure --prefix=/usr --localstatedir=/var --sysconfdir=/etc
#make
#make install
#cp /lib/udev/65-drbd.rules /lib/udev/rules.d/
#/bin/rm -rf /tmp/drbdinst

配置

Corosync配置

从/etc/corosync/corosync.conf.example.udpu复制sample文件到/etc/corosync/corosync.conf，根据实际配置编辑：

compatibility: whitetank

service {
        ver: 1
        name: pacemaker
        use_logd: yes
}

logging {
        fileline: off
        to_logfile: yes
        logfile: /var/log/cluster/corosync.log
        to_stderr: no
        debug: off
        timestamp: on
        to_syslog: yes
        logger_subsys {
                subsys: QUORUM
                debug: off
        }
}

totem {
        version: 2
        token: 3000
        secauth: on
        rrp_mode: active

        interface {
                ringnumber: 0
                bindnetaddr: 10.0.0.0
                mcastaddr: 226.94.1.1
                mcastport: 5405
        }
}

quorum {
        provider: corosync_votequorum
        expected_votes: 2
}

如果secauth设置为on，则需要生成一个加密key用于集群通信：

# corosync-keygen

生成完成后，复制到其他节点：

# scp -p /etc/corosync/authkey controllerv:/etc/corosync/

在所有节点上启动服务：

# systemctl start corosync pacemaker

查看配置、membership及quorum API

# corosync-cfgtool -s

# corosync-cmapctl | grep members

# corosync-quorumtool -l  或pcs status corosync

Pacemaker配置

首先验证pacemaker安装：

# ps axf
49091 ?        Ss     0:00 /usr/sbin/pacemakerd -f
49092 ?        Ss     0:00  \_ /usr/libexec/pacemaker/cib
49093 ?        Ss     0:00  \_ /usr/libexec/pacemaker/stonithd
49094 ?        Ss     0:00  \_ /usr/libexec/pacemaker/lrmd
49095 ?        Ss     0:00  \_ /usr/libexec/pacemaker/attrd
49096 ?        Ss     0:00  \_ /usr/libexec/pacemaker/pengine
49097 ?        Ss     0:00  \_ /usr/libexec/pacemaker/crmd

检查集群状态：

# crm status
Last updated: Tue Dec  2 23:04:29 2014
Last change: Tue Dec  2 22:54:01 2014 via crmd on node1
Stack: corosync
Current DC: NONE
2 Nodes configured
0 Resources configured


Online: [ controller controllerv ]

查看配置：

# crm configure show
node 167772171: controller
node 167772172: controllerv
property cib-bootstrap-options: \
        dc-version=1.1.10-32.el7_0.1-368c726 \
        cluster-infrastructure=corosync

cibadmin --query --local或pcs cluster cib查看xml格式的cib信息。

如下命令验证配置，可以发现问题：

# crm_verify -L -V
   error: unpack_resources:     Resource start-up disabled since no STONITH resources have been defined
   error: unpack_resources:     Either configure some or disable STONITH with the stonith-enabled option
   error: unpack_resources:     NOTE: Clusters with shared data need STONITH to ensure data integrity
Errors found during check: config not valid

因为测试没有STONITH设备，所以禁用STONITH：（STONITH会在另一篇不可做详细介绍）

# crm configure property stonith-enabled=false

双节点忽略quorum：

# crm configure property no-quorum-policy=ignore

修改后查看配置并验证：

# crm configure show
node 167772171: controller
node 167772172: controllerv
property cib-bootstrap-options: \
        dc-version=1.1.10-32.el7_0.1-368c726 \
        cluster-infrastructure=corosync \
        stonith-enabled=false \
        no-quorum-policy=ignore
# crm_verify -L
#

配置DRBD

MARIADB

MySQL/DRBD/Pacemaker/Corosync Stack

编辑/etc/drbd.conf

# You can find an example in  /usr/share/doc/drbd.../drbd.conf.example

include "drbd.d/global_common.conf";
include "drbd.d/*.res";

使用global_common.conf，后面还需要配置rabbitmq。

global {
        usage-count no;
}

common {
        protocol C;     # C 同步 A 异步 B 半同步
        handlers {
                pri-on-incon-degr "/usr/lib/drbd/notify-pri-on-incon-degr.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b > /proc/sysrq-trigger ; reboot -f";
                pri-lost-after-sb "/usr/lib/drbd/notify-pri-lost-after-sb.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b > /proc/sysrq-trigger ; reboot -f";
                local-io-error "/usr/lib/drbd/notify-io-error.sh; /usr/lib/drbd/notify-emergency-shutdown.sh; echo o > /proc/sysrq-trigger ; halt -f";
        }
        startup {
                wfc-timeout 30; #DRBD资源连接
                degr-wfc-timeout 30;    #节点在degraded cluster
        }
        disk {
                on-i