Showing posts with label cluster. Show all posts
Showing posts with label cluster. Show all posts

Tuesday, May 22, 2012

My Cluster Crash :(

Ok.. today is my bad day.. This is the first time that my snapshot doesn't work... You know why??? It is because the server is cluster.. We cannot simply revert your snapshot for cluster server. 

What you should do actually you should copy the folder and move to the current server. This is for moodle application. 


WARGH...keja dah aaa menimbun.. tambah lg satu masalah.. :( sedih... Tapi, it is a process of learning... Go shariha go..

Thursday, January 19, 2012

Cluster Ubuntu - DRBD

Before I start sharing my knowledge here, I would like to give my best reward to Bro John who teach me and sis salina.. :)

Hoyeee... let start writing..

What is cluster.. ???
A group of the same or similar elements gathered or occurring closely together.

Why need cluster..
Because it is for backup purposes and will reduce the possibility for a site to down since the both server are working together.


update the package
#apt-get update

Untuk install cluster, kena ada 2 server at least... Kalu nk buat all the steps... Make sure do it the both server for each step before go to another step :

1. Install apache2
#apt-get install apache2
-> check idup ke tk -> pi browser //ip

2. Install php5
#apt-get install php5

3. Install libapache2-mod-php5

4. Restart Apache
#/etc/init.d/apache2 restart

5. Check package info
#dpkg --get-selection

6. Install php extension
#apt-get -y install php5-cli php5-common php5... etc
-y untuk dia terus pilih yes..
tambah jerk php extension yang lain untuk install serentak


Untuk Present Hardisk
pi kat vmware - add hardisk
7. #fdisk -l
kalau tak jumpa #reboot

8. Install drbd
#apt-get install drbd8-utils
check samada yang nih yang paling update kat web dia atau browsing pasal drbd

9. nano /etc/drbd.conf

- install drbd file refer here http://dev.mysql.com/doc/mysql-ha-scalability/en/ha-drbd-install-drbd.html

- now ubuntu 10.04 using only this apt-get install drbd8-utils
example on drbd.conf :

global {
usage-count no;
}
resource r0 {
protocol C;
startup {
become-primary-on both;
}
net {
allow-two-primaries;
cram-hmac-alg "sha1";
shared-secret "k3n4Tuk4r";
after-sb-0pri discard-least-changes;
after-sb-1pri violently-as0p;
after-sb-2pri violently-as0p;
rr-conflict violently;
}
syncer {
verify-alg md5;
al-extents 257;
rate 40M;
}

on pm-vst-drbd01 {
device /dev/drbd0;
disk /dev/sdb;
address 172.18.33.33:7788;
flexible-meta-disk internal;
}

on pm-vst-drbd02 {
device /dev/drbd0;
disk /dev/sdb;
address 172. 18.33.34:7788;
flexible-meta-disk internal;
}
}

10. Install OCFS (Oracle Cluster Site System)
#apt-get -y install ocfs2-tools ocfs2console
create folder ocfs2 and touch cluster.conf inside the folder

example :

#nano /etc/ocfs2/cluster.conf
cluster:
node_count = 2
name = mysqlocfs

node:
ip_port = 7777
ip_address = 172.18.33.33
number = 0
name = pm-vst-drbd01
cluster = mysqlocfs
node:
ip_port = 7777
ip_address = 172. 18.33.34
number = 1
name = pm-vst-drbd02
cluster = mysqlocfs

11. Check status ocfs2
#/etc/init.d/o2cb status

12. add HDD to each server and reboot the server to detect the HDD but do not format it just leave it.

13. Run OCFS
#dpkg-reconfigure -p medium -f readline ocfs2-tools

example :
Would you like to start an OCFS2 cluster (O2CB) at boot time? yes
Name of the cluster to start at boot time: ocfs2
The O2CB heartbeat threshold sets up the maximum time in seconds that a node
awaits for an I/O operation. After it, the node "fences" itself, and you will
probably see a crash.

It is calculated as the result of: (threshold - 1) x 2.

Its default value is 31 (60 seconds).

Raise it if you have slow disks and/or crashes with kernel messages like:

o2hb_write_timeout: 164 ERROR: heartbeat write timeout to device XXXX after NNNN
milliseconds
O2CB Heartbeat threshold: 31
Loading filesystem "configfs": OK
Mounting configfs filesystem at /sys/kernel/config: OK
Loading stack plugin "o2cb": OK
Loading filesystem "ocfs2_dlmfs": OK
Mounting ocfs2_dlmfs filesystem at /dlm: OK
Setting cluster stack "o2cb": OK
Starting O2CB cluster ocfs2: OK

14. Buat DRBD partition
#drbdadm create-md all
- run drbdadm create-md all (If you see error please check your drbd.conf and edit disk conf. Make sure you have invalid HDD path)

15. Start DRBD
#/etc/init.d/drbd start -> yang nih kena buat serentak utk dua2 server.. sbb nnti dia akan cari yang lg satu

16. Overwrite data
#drbdadm -- --overwrite-data-of-peer primary all

17.Format hardisk (p/s: JANGAN BUAT SERENTAK.. buat satu2... !!!!!!!!!!)
#mkfs -t ocfs2 -N 2 -L ocfs2_drbd0 /dev/drbd0
- create drbd filesystem mkfs.ext3 /dev/drbd0 or mkfs -t ocfs2 -N 2 -L ocfs2_drbd0 /dev/drbd0

18. ada lg step... to be continued.. :)