COROSYNC+PACEMAKER+DRBD enabling high availability of Web services

One: Experimental environment

Node	OS	Ip	Drbd_ip	DRBD with HDD	Vip
Web1	centos5.10	192.168.10.11	172.16.1.1	/dev/sdb	192.168.10.100
Web2	centos5.10	192.168.10.12	172.16.1.2	/dev/sdb

1. Where the two-node IP address is set as above:

2. Two nodes have been configured with mutual SSH trust and have done time synchronization

Two: Install related software (both nodes 1 and 2 are installed)

1. Install Corosync, pacemaker

Download the corresponding RPM package at the address below

http://clusterlabs.org/rpm/epel-5/x86_64/

The RPM package for this download is:

cluster-glue-1.0.6-1.6.el5.x86_64.rpm

cluster-glue-libs-1.0.6-1.6.el5.x86_64.rpm

corosync-1.2.7-1.1.el5.x86_64.rpm

corosynclib-1.2.7-1.1.el5.x86_64.rpm

heartbeat-3.0.3-2.3.el5.x86_64.rpm

heartbeat-libs-3.0.3-2.3.el5.x86_64.rpm

LIBESMTP-1.0.4-5.EL5.X86_64.RPM//This package is downloaded from the Epel source

pacemaker-1.0.12-1.el5.centos.x86_64.rpm

pacemaker-libs-1.0.12-1.el5.centos.x86_64.rpm

resource-agents-1.0.4-1.1.el5.x86_64.rpm

Installation:

[Root@web1 ~]# for I in 1 2; Do ssh web$i yum-y--nogpgcheck localinstall/root/*.rpm; Done

3. Install Apache and set not to start randomly

[Root@web1 ~]# for I in 1 2; Do ssh web$i yum-y install httpd; Done

[Root@web1 ~]# for I in 1 2; Do ssh web$i chkconfig httpd off; Done

4. Install DRBD and set not to start randomly

[Root@web1 ~]# for I in 1 2; Do ssh web$i yum-y install drbd83 kmod-drbd83; Done

[Root@web1 ~]# for I in 1 2; Do ssh web$i chkconfig drbd off; Done

Three: Configure DRBD

1. [Root@web1 ~]# cp/usr/share/doc/drbd83-8.3.15/drbd.conf/etc/drbd.conf

2. [Root@web1 ~]# cd/etc/drbd.d/

3.[root@web1 drbd.d]# Cat global_common.conf//Only the Change section is listed here, not listed by default

Global {

Usage-count No;

}

Common {

Protocol C;

NET {

Cram-hmac-alg SHA1;

Shared-secret "WJCAIYF";

}

Syncer {

Rate 56M;

}

}

4. New Resource R0

[Root@web1 drbd.d]# Touch R0.res

[Root@web1 drbd.d]# Cat R0.res

Resource R0 {

device/dev/drbd0;

Disk/dev/sdb;

Meta-disk internal;

On web1 {

Address 172.16.1.1:7789;

}

On web2 {

Address 172.16.1.2:7789;

}

}

5. Copy the global_common.conf and r0.res to the web2 corresponding directory

[Root@web1 drbd.d]# SCP global_common.conf r0.res web2:/etc/drbd.d/

6. Create metadata for resource r0 (both nodes 1 and 2 are created)

[Root@web1 ~]# for I in 1 2; Do ssh web$i drbdadm create-md r0; Done

7. Start the DRBD service

[Root@web1 ~]#/ETC/INIT.D/DRBD start

[Root@web2 ~]#/ETC/INIT.D/DRBD start

8. Set Web1 to start synchronizing data for the primary node

[Root@web1 ~]# Drbdadm----Overwrite-data-of-peer primary r0

9. View the/PROC/DRBD to determine the synchronization status

[Root@web1 ~]# CAT/PROC/DRBD

version:8.3.15 (api:88/proto:86-97)

Git-hash:0ce4d235fc02b5c53c1c52c53433d11a694eab8cbuild by mockbuild@builder10.centos.org, 2013-03-27 16:01:26

0:cs:connected ro:primary/secondaryds:uptodate/uptodate C R-----

Ns:4 nr:8 dw:12 dr:17 al:0 bm:1 lo:0 pe:0 ua:0 ap:0 ep:1 wo:b oos:0

The above red font indicates that synchronization is complete.

10. Create a Ext3 file system

[Root@web1 ~]# mkfs.ext3/dev/drbd0

11. Mount the/dev/drbd0 to the/var/www/html directory and place a test page before uninstalling the Mount

[Root@web1 ~]# mount/dev/drbd0/var/www/html/

[Root@web1 ~]# echo "This is a Testpage" >/var/www/html/index.html

[Root@web1 ~]# umount/var/www/html/

12. Restore the DRBD status to Secondary/secondary and stop the DRBD service

[Root@web1 ~]# Drbdadm secondary R0

[Root@web1 ~]# for I in 1 2; do ssh WEB$I/ETC/INIT.D/DRBD stop; Done

Now that the DRBD configuration is complete

Four: Configuration Corosync

1.[root@web1 ~]# cd/etc/corosync/

2.[ROOT@WEB1 corosync]# CP corosync.conf.example corosync.conf

3. The completed configuration file is as follows:

[Root@web1 corosync]# Cat corosync.conf

# Please read the corosync.conf.5 manualpage

Compatibility:whitetank

Totem {

Version:2

Secauth:off