Apache Fail Over with MON

السلام علیکم و رحمہ اللہ
ادہر جو ٹیوٹوریل پیش کیا جارہا ہے اسکا انگریزی ورژن آپ http://adamdesktop.blogspot.com/2006_10_01_archive.html
سے حاصل کرسکتے ہیں۔ اس تمام مضمون میں تیکنیکی لفظوں کے معین اردو الفاظ مجھے معلوم نہیں۔ لہزا جن صاحب کو بھی اس بارے میں علم ہو وہ تصیح‌کرسکتا ہے۔ میں‌کوشش کروں گا کہ اپنے مفہوم کو مناسب الفاظ میں‌بیان کرسکوں۔

یہ مضمون جاننے سے پہلے آپکو کیا کیا آنا چاہیے:
××××××××××××××××××××××××××××××××
- لینکس کی مناسب کمانڈز۔
- ویب سرور اور Apache کی تنصیب کے بارے میں علم ہو۔

مو ضوع:
-----------

HA CLuster for Apache web server. یعنی
ویب سرور اگر خدا نخواستہ کسی وجہ سے خراب ہو جائے تو صارفین کو ویب سروس کے حصول میںکوئی دقت نہ ہو۔

سسٹم کی ضروریات:
-----------------------------------
دو کمپیوٹر کی مشینیں جو لینکس چلا رہی ہوں اور ایپاچی ویب سرور۔ ایک کمپیٹر آقا اور دوسرا غلام کہلائے گا عینی
master and slave.
Download Cluster Software: (کلسٹر کا سافٹ ویر ڈاونلوڈ کریں)
----------------------------------

http://www.ultramonkey.org/download/3/rh.el.3/RPMS/

اب ان سب ر پی ایمز کو ایک فولڈر میں محفوظ کرلیں ۔ نیچے دی گی سکرپٹ کو مناسب پیرمیشنز کے ساتھ چلائیں‌تو خود بخود سارے ر پی ایمز انسٹال ہو جائیںگے۔

************* install.sh ***************************************

#! /bin/bash

rpm -ivh libnet-1.1.0-1.rh.el.1.i386.rpm

rpm -ivh libnet-debuginfo-1.1.0-1.rh.el.1.i386.rpm

rpm -ivh heartbeat-pils-1.2.3-2.rh.el.3.0.i386.rpm

rpm -ivh heartbeat-stonith-1.2.3-2.rh.el.3.0.i386.rpm

rpm -ivh perl-Parse-RecDescent-1.80-1.rh.el.um.1.noarch.rpm

rpm -ivh perl-Mail-IMAPClient-2.2.7-1.rh.el.um.1.noarch.rpm

rpm -ivh perl-Net-SSLeay-1.23-1.rh.el.um.1.i386.rpm

rpm -ivh perl-IO-Socket-SSL-0.92-1.rh.el.um.1.noarch.rpm

rpm -ivh perl-Authen-SASL-2.03-1.rh.el.um.1.noarch.rpm

rpm -ivh heartbeat-1.2.3-2.rh.el.3.0.i386.rpm

rpm -ivh heartbeat-ldirectord-1.2.3-2.rh.el.3.0.i386.rpm

rpm -ivh --nodeps heartbeat-ldirectord-1.2.3-2.rh.el.3.0.i386.rpm

################################

اب یہ کمانڈ چلائیں:

[root@hrdfphp02 ha]# vi install.sh

[root@hrdfphp02 ha]# chmod 755 install.sh

[root@hrdfphp02 ha]# ./install.sh

اس سافٹ ویر کا آصل نام ہارٹ بیٹ ہے۔ جو مقبول عام زمانہ ہے۔
اب اسے کنفیگر کرتے ہین:
---------------------------
اب دونوں کمپیوٹروں‌ کی serial cables (null modems) کو ایک دوسرے سے باہم منسلک کردیں:
اور درج ذیل کمانڈز چلائیں؛
Enter the master and slave hosts in

[root@HRDFMYSQL01 ha.d]# cat /etc/hosts

# Do not remove the following line, or various programs

# that requires network functionality will fail.

127.0.0.1 HRDFMYSQL01 localhost.localdomain localhost

212.100.220.66 HRDFMYSQL01

212.100.220.67 HRDFMYSQL02

[root@hrdfphp01 ~]# cd /etc/ha.d

[root@hrdfphp01 ~]# vi ha.cf

********************** ha.cf ********************************************

logfile /var/log/ha-log

debugfile /var/log/ha-debug

logfacility local0

keepalive 1

deadtime 20

warntime 10

initdead 60

udpport 694

#bcast eth1

serial /dev/ttyS0

#ucast eth1 192.168.16.5

auto_failback on

node HRDFPHP01

node HRDFPHP02

#respawn hacluster /usr/lib/heartbeat/ipfail # Failover on network failures

[root@hrdfphp01 ha.d]# cat haresources

HRDFPHP01 212.100.220.67 apache mon-start

[root@hrdfphp01 ha.d]# cat authkeys

auth 1

1 crc


Ha.cf and haresource یہ دونوں فائیلیں دونوں کمبپیوٹریوں‌پر ایک جیسی ہونی چاہیے۔ .

Change /etc/ha.d/resource.d/apache to search for the conf file,
and change it to /etc/httpd/conf/httpd.conf

اب اپنے اپاچی کو کنفیگر کریں:
----------------------------------------------------------------------------------------------------------

Change the /etc/httpd/conf/httpd.conf the Listen directive to the VIP:

Listen 212.100.220.67:80

[root@hrdfphp01 local] chkconfig –level 2345 httpd off

[root@hrdfphp02 local] chkconfig –level 2345 httpd off

کنفیگر کریں MON:

[root@hrdfphp01 local] mkdir –p /usr/local/perl-module

[root@hrdfphp01 local] cd /usr/local/perl-module

Download mon from: http://www.kernel.org/software/mon/

Download the Perl Modules from:
http://search.cpan.org/author/PRYAN/Period-1.20/

http://search.cpan.org/CPAN/authors/id/ ... .42.tar.gz

http://search.cpan.org/CPAN/authors/id/ ... .tar.gz%20

http://search.cpan.org/CPAN/authors/id/ ... .tar.gz%20

[root@hrdfphp01 perl-module] mv mon-0.99-9.tar.gz /etc/ha.d
[root@hrdfphp01 perl-module] tar xzvf

Follow the perl modules installation by:

perl Makefile.PL

make

make test

make install

[root@hrdfphp01 ha.d] cd /etc/ha.d; tar xzvf mon-0.99-9.tar.gz

[root@hrdfphp01 ha.d] mv mon-0.99-9 mon

[root@hrdfphp01 ha.d] cd mon

[root@hrdfphp01 mon] vi etc/mon.cf

alertdir = /etc/ha.d/mon/alert.d

mondir = /etc/ha.d/mon/mon.d

statedir = /etc/ha.d/mon/state.d

loir = /var/log/

maxprocs = 20

histlength = 100

randstart = 10s

authtype = getpwnam

hostgroup web-fe 212.100.220.67

watch web-fe

service http

interval 10s

monitor http.monitor -p 80 -u /test.html

allow_empty_group

period wd {Sat-Fri}

alert bring-ha-down.alert -S "web server (Master) down" \

hrdfonline@gmail.com

upalert mail.alert -S "web server (Master) is back up" \

hrdfonline@gmail.com

alertevery 600s

alertafter 2

[root@hrdfphp01 mon] cp etc/mon.cf .

[root@hrdfphp01 mon]# cat mon/alert.d/bring-ha-down.alert

/etc/ha.d/mon/alert.d/mail.alert $*

/etc/init.d/heartbeat stop

[root@hrdfphp01 mon]# cp mon-start ../resource.d/mon-start

(check for the files for absolute paths)

Now on Both Systems:

[root@hrdfphp01 ha.d]#service heartbeat restart

[root@hrdfphp02 ha.d]#service heartbeat restart

[root@hrdfphp01 ha.d]# tail –f /var/log/ha-log

Test Cases:

Stop heartbeat service at master (hardware or system goes down or network unreachable, etc)

Slave become master, logs shows:

heartbeat: 2006/10/09_13:49:11 info: Received shutdown notice from 'hrdfphp01'.

heartbeat: 2006/10/09_13:49:11 info: Resources being acquired from hrdfphp01.

heartbeat: 2006/10/09_13:49:11 info: acquire local HA resources (standby).

heartbeat: 2006/10/09_13:49:11 info: local HA resource acquisition completed (standby).

heartbeat: 2006/10/09_13:49:11 info: No local resources [/usr/lib/heartbeat/ResourceManager listkeys hrdfphp02] to acquire.

heartbeat: 2006/10/09_13:49:11 info: Standby resource acquisition done [all].

heartbeat: 2006/10/09_13:49:11 info: Running /etc/ha.d/rc.d/status status

heartbeat: 2006/10/09_13:49:11 info: Taking over resource group 212.100.220.67

heartbeat: 2006/10/09_13:49:11 info: Acquiring resource group: hrdfphp01 212.100.220.67 apache mon-start

heartbeat: 2006/10/09_13:49:11 info: Running /etc/ha.d/resource.d/IPaddr 212.100.220.67 start

heartbeat: 2006/10/09_13:49:11 info: /sbin/ifconfig eth0:0 212.100.220.67 netmask 255.255.255.248 broadcast 212.100.220.71

heartbeat: 2006/10/09_13:49:11 info: Sending Gratuitous Arp for 212.100.220.67 on eth0:0 [eth0]

heartbeat: 2006/10/09_13:49:11 /usr/lib/heartbeat/send_arp -i 1010 -r 5 -p /var/lib/heartbeat/rsctmp/send_arp/send_arp-212.100.220.67 eth0 212.100.220.67 auto 212.100.220.67 ffffffffffff

heartbeat: 2006/10/09_13:49:11 info: Running /etc/ha.d/resource.d/apache start

heartbeat: 2006/10/09_13:49:12 info: httpd: Could not determine the server's fully qualified domain name, using 127.0.0.1 for ServerName

heartbeat: 2006/10/09_13:49:12 info: Running /etc/ha.d/resource.d/mon-start start

heartbeat: 2006/10/09_13:49:12 info: /usr/lib/heartbeat/mach_down: nice_failback: foreign resources acquired

heartbeat: 2006/10/09_13:49:12 info: mach_down takeover complete.

heartbeat: 2006/10/09_13:49:12 info: mach_down takeover complete for node hrdfphp01.

Slave now took over the Virtual IP:

[root@hrdfphp02 ha]# ifconfig

eth0 Link encap:Ethernet HWaddr 00:14:C2:58:AE:31

inet addr:212.100.220.69 Bcast:212.100.220.71 Mask:255.255.255.248

inet6 addr: fe80::214:c2ff:fe58:ae31/64 Scope:Link

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:1834 errors:0 dropped:0 overruns:0 frame:0

TX packets:981 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:270832 (264.4 KiB) TX bytes:465376 (454.4 KiB)

Interrupt:201 Memory:f7cb0000-f7cc0000

eth0:0 Link encap:Ethernet HWaddr 00:14:C2:58:AE:31

inet addr:212.100.220.67 Bcast:212.100.220.71 Mask:255.255.255.248

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

Interrupt:201 Memory:f7cb0000-f7cc0000

eth1 Link encap:Ethernet HWaddr 00:14:C2:58:AE:30

inet addr:192.168.16.3 Bcast:192.168.16.255 Mask:255.255.255.0

inet6 addr: fe80::214:c2ff:fe58:ae30/64 Scope:Link

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:11629 errors:0 dropped:0 overruns:0 frame:0

TX packets:6848 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:3631751 (3.4 MiB) TX bytes:1121085 (1.0 MiB)

Interrupt:209 Memory:f7ca0000-f7cb0000

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

inet6 addr: ::1/128 Scope:Host

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:4003064 errors:0 dropped:0 overruns:0 frame:0

TX packets:4003064 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:378830313 (361.2 MiB) TX bytes:378830313 (361.2 MiB)

Master Came back:

[root@hrdfphp02 ha]# tail -f /var/log/ha-log

heartbeat: 2006/10/09_13:52:27 info: Releasing resource group: hrdfphp01 212.100.220.67 apache mon-start

heartbeat: 2006/10/09_13:52:27 info: Running /etc/ha.d/resource.d/mon-start stop

heartbeat: 2006/10/09_13:52:27 info: Running /etc/ha.d/resource.d/apache stop

heartbeat: 2006/10/09_13:52:28 Killing apache PID 29557

heartbeat: 2006/10/09_13:52:29 info: Running /etc/ha.d/resource.d/IPaddr 212.100.220.67 stop

heartbeat: 2006/10/09_13:52:29 info: /sbin/route -n del -host 212.100.220.67

heartbeat: 2006/10/09_13:52:29 info: /sbin/ifconfig eth0:0 down

heartbeat: 2006/10/09_13:52:29 info: IP Address 212.100.220.67 released

heartbeat: 2006/10/09_13:52:29 info: foreign HA resource release completed (standby).

heartbeat: 2006/10/09_13:52:29 info: Local standby process completed [foreign].

heartbeat: 2006/10/09_13:52:30 WARN: 1 lost packet(s) for [hrdfphp01] [10:12]

heartbeat: 2006/10/09_13:52:30 info: remote resource transition completed.

heartbeat: 2006/10/09_13:52:30 info: No pkts missing from hrdfphp01!

heartbeat: 2006/10/09_13:52:30 info: Other node completed standby takeover of foreign resources.

Apache service goes down at Master:

heartbeat: 2006/10/09_13:52:30 info: Other node completed standby takeover of foreign resources.

heartbeat: 2006/10/09_13:54:48 info: Received shutdown notice from 'hrdfphp01'.

heartbeat: 2006/10/09_13:54:48 info: Resources being acquired from hrdfphp01.

heartbeat: 2006/10/09_13:54:48 info: acquire local HA resources (standby).

heartbeat: 2006/10/09_13:54:48 info: No local resources [/usr/lib/heartbeat/ResourceManager listkeys hrdfphp02] to acquire.

heartbeat: 2006/10/09_13:54:48 info: local HA resource acquisition completed (standby).

heartbeat: 2006/10/09_13:54:48 info: Standby resource acquisition done [foreign].

heartbeat: 2006/10/09_13:54:48 info: Running /etc/ha.d/rc.d/status status

heartbeat: 2006/10/09_13:54:48 info: Taking over resource group 212.100.220.67

heartbeat: 2006/10/09_13:54:48 info: Acquiring resource group: hrdfphp01 212.100.220.67 apache mon-start

heartbeat: 2006/10/09_13:54:48 info: Running /etc/ha.d/resource.d/IPaddr 212.100.220.67 start

heartbeat: 2006/10/09_13:54:48 info: /sbin/ifconfig eth0:0 212.100.220.67 netmask 255.255.255.248 broadcast 212.100.220.71

heartbeat: 2006/10/09_13:54:48 info: Sending Gratuitous Arp for 212.100.220.67 on eth0:0 [eth0]

heartbeat: 2006/10/09_13:54:48 /usr/lib/heartbeat/send_arp -i 1010 -r 5 -p /var/lib/heartbeat/rsctmp/send_arp/send_arp-212.100.220.67 eth0 212.100.220.67 auto 212.100.220.67 ffffffffffff

heartbeat: 2006/10/09_13:54:49 info: Running /etc/ha.d/resource.d/apache start

heartbeat: 2006/10/09_13:54:49 info: httpd: Could not determine the server's fully qualified domain name, using 127.0.0.1 for ServerName

heartbeat: 2006/10/09_13:54:49 info: Running /etc/ha.d/resource.d/mon-start start

heartbeat: 2006/10/09_13:54:49 info: /usr/lib/heartbeat/mach_down: nice_failback: foreign resources acquired

heartbeat: 2006/10/09_13:54:49 info: mach_down takeover complete.

heartbeat: 2006/10/09_13:54:49 info: mach_down takeover complete for node hrdfphp01.

Slave up after two minutes.

 

ماشاء اللہ کا اچھی شئیرنگ ہے پڑھی ہے کام کرنے کے بعد پھر آگے مدد چاہوں گا