High Availability Cluster High-Passive MariaDB-Server on Red Hat 7

A high availability cluster is a set of two or more machines that are characterized by maintaining a series of shared services and being constantly monitored. ===

What is an HA Cluster?

A high availability cluster is a set of two or more machines which are characterized by maintaining a series of shared services and constantly monitoring each other. Can

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Install ISCSI

Bash

yum -y install iscsi-initiator-utils device-mapper-multipath

We add the multipathd configuration

Bash

cat /etc/multipath.conf
defaults {
user_friendly_names yes
path_grouping_policy multibus
path_checker readsector0
failback immediate
}

We restart the multipathd and add it to the beginning

Bash

service multipathd start
Redirecting to /bin/systemctl start multipathd.service
chkconfig multipathd on
Note: Forwarding request to ‘systemctl enable multipathd.service’.

We carry out the discovery

text

iscsiadm -m discovery -t st -p 192.168.20.1

192.168.20.1:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.24.1:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.20.2:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.24.2:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.24.3:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.20.3:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.24.4:3260,1 iqn.2010-06.com.purestorage:flasharray

192.168.20.4:3260,1 iqn.2010-06.com.purestorage:flasharray

We make the connection

text

iscsiadm -m node -L automatic

We rescan

text

iscsiadm -m session –rescan

We restart the iscsi service

Bash

service iscsi restart

We check the session

text

iscsiadm -m sesión

We check the multipath

text

multipath -ll

mpatha (3624a93708731da97f48571620001105a) dm-6 PURE ,FlashArray

size=232G features=’0′ hwhandler=’0′ wp=rw

`-+- policy=’service-time 0′ prio=1 status=active

|- 3:0:0:10 sdb 8:16 active ready running

|- 4:0:0:10 sdc 8:32 active ready running

|- 5:0:0:10 sdd 8:48 active ready running

|- 6:0:0:10 sde 8:64 active ready running

|- 7:0:0:10 sdf 8:80 active ready running

|- 10:0:0:10 sdh 8:112 active ready running

|- 8:0:0:10 sdg 8:96 active ready running

`- 9:0:0:10 sdi 8:128 active ready running

We create the volume

text

pvcreate /dev/mapper/mpatha

vgcreate vg_mysql /dev/mapper/mpatha

lvcreate -l+100%FREE -n lv_mysql vg_mysql

We format the volume

text

mkfs.xfs /dev/mapper/vg_mysql-lv_mysql

We add the disk to /etc/fstab

text

/dev/mapper/vg_mysql-lv_mysql /mysql xfs defaults 0 0

We configure the /etc/hosts file

text

192.167.1.235 redorbitaclus02.redorbita.com redorbitaclus02

192.167.1.234 redorbitaclus01.redorbita.com redorbitaclus01

We add the subscription

text

subscription-manager list –available

text

subscription-manager attach –pool=8a85f981550f53aa01550fbfd43c69aa

subscription-manager repos –enable=rhel-ha-for-rhel-7-server-rpms

We install the necessary packaging:

Bash

yum install pcs fence-agents-all

We enable the rules in the firewall or deactivate it

Bash

firewall-cmd –permanent –add-service=high-availability

firewall-cmd –add-service=high-availability
systemctl stop firewalld

systemctl disable firewalld

We change the password to the cluster user

text

passwd hacluster

Changing password for user hacluster.

New password:

Retype new password:

passwd: all authentication tokens updated successfully.

We start the service.

Bash

systemctl start pcsd.service

systemctl enable pcsd.service

Created symlink from /etc/systemd/system/multi-user.target.wants/pcsd.service to /usr/lib/systemd/system/pcsd.service.

Authorize nodes and user, perform on a single node:

yaml

pcs cluster auth  redorbitaclus01  redorbitaclus02

Username: hacluster

Password:

redorbitaclus02: Authorized

redorbitaclus01: Authorized

We create the cluster and enable cluster when starting machines

text

pcs cluster setup –start –name redorbitaclus redorbitaclus01 redorbitaclus02

Shutting down pacemaker/corosync services…

Redirecting to /bin/systemctl stop  pacemaker.service

Redirecting to /bin/systemctl stop  corosync.service

Killing any remaining services…

Removing all cluster configuration files…

redorbitaclus01: Succeeded

redorbitaclus02: Succeeded

Starting cluster on nodes: redorbitaclus01, redorbitaclus02…

redorbitaclus01: Starting Cluster…

redorbitaclus02: Starting Cluster…

Synchronizing pcsd certificates on nodes redorbitaclus01, redorbitaclus02…

redorbitaclus02: Success

redorbitaclus01: Success
Restaring pcsd on the nodes in order to reload the certificates…

redorbitaclus02: Success

redorbitaclus01: Success
pcs cluster enable –all

redorbitaclus01: Cluster Enabled

redorbitaclus02: Cluster Enabled

We check the status of the cluster

text

pcs cluster status

Cluster Status:

Last updated: Thu Jun  2 11:58:37 2016         Last change: Thu Jun  2 11:38:40 2016 by hacluster via crmd on redorbitaclus01

Stack: corosync

Current DC: redorbitaclus01 (version 1.1.13-10.el7_2.2-44eb2dd) – partition with quorum

2 nodes and 0 resources configured

Online: [ redorbitaclus01 redorbitaclus02 ]
PCSD Status:

redorbitaclus01: Online

redorbitaclus02: Online

We install the service which we are going to cluster, in our case mysql.

Bash

yum install MariaDB-server MariaDB-client

We generate the Fence user in vmware, to do this we go to Roles in vcenter

We go to the project folder, right button > Add Permission…

We access through the web through Port 2224

We log in with the hacluster user

We added the cluster to be managed by web.

Next we are going to configure the Fence, to do this we click on Fence devices > Add

We add the IP or name of the DNS server in ipaddr, the user that we previously created and the corresponding password.

Next we are going to create a resource Recurces > Add

We configure a resource which performs the mounting of the file system.

Now we create a group and associate it with the resource created previously.

We create another resource for the cluster IP

We create the resource for the mysql service

Finally we configure /etc/my.cnf of our MariaDB-Server

config

cat /etc/my.cnf
For advice on how to change settings please see

# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
[mysqld]

sql_mode=»STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION»

#

# Remove leading # and set to the amount of RAM for the most important data

# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

innodb_buffer_pool_size = 5G

#

# Remove leading # to turn on a very important data integrity option: logging

# changes to the binary log between backups.

# log_bin

#

# Remove leading # to set options mainly useful for reporting servers.

# The server defaults are faster for transactions and fast SELECTs.

# Adjust sizes as needed, experiment to find the optimal values.

join_buffer_size = 64M

# sort_buffer_size = 2M

read_rnd_buffer_size = 16M

bulk_insert_buffer_size = 64M

#datadir=/var/lib/mysql

innodb_thread_concurrency = 10

innodb_buffer_pool_instances=6

#thread_concurrency = 12

innodb_autoextend_increment = 512

innodb_log_file_size = 1G

read_buffer_size = 2M

datadir=/mysql

socket=/var/lib/mysql/mysql.sock
#skip_grant_tables
# Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0
log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid
validate_password_policy=LOW
user = mysql

port = 3306

basedir = /usr

tmpdir = /tmp

language = /usr/share/mysql/english

symbolic-links  =0

max_allowed_packet = 512M

innodb_file_per_table =1

lower_case_table_names = 1

skip-name-resolve=1
# Query Cache #

query_cache_type = 0

query_cache_limit = 32M

query_cache_size = 64M
# For MyISAM #

key_buffer_size = 32M

myisam_sort_buffer_size = 128M

myisam_max_sort_file_size = 10G

#myisam_max_extra_sort_file_size = 10G

myisam_repair_threads = 1
# LOGGING #

log_queries_not_using_indexes = 1

slow_query_log = 1

slow_query_log_file = /var/lib/mysql/mysqld-slow-query.log

log_queries_not_using_indexes = 0
# Caches #

tmp_table_size = 256M

max_heap_table_size = 256M

max_connections = 500

thread_cache_size = 50

open_files_limit  = 5000

table_definition_cache = 4096

table_open_cache = 1024

We start the cluster

text

crm_resource start redorbitaclus

We check the status of the cluster

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pcs cluster status
Cluster Status:

Last updated: Mon Jun 6 15:59:46 2016 Last change: Mon Jun 6 13:36:01 2016 by

hacluster via cibadmin on redorbitaclus01.redorbita.com

Stack: corosync

Current DC: redorbitaclus01.redorbita.com (version 1.1.13-10.el7_2.2- 44eb2dd) – partition with

quorum

2 nodes and 3 resources configured

Online: [ redorbitaclus01.redorbita.com ]

OFFLINE: [ redorbitaclus02.redorbita.com ]

PCSD Status:

redorbitaclus01.redorbita.com: Online

redorbitaclus02.redorbita.com: Online

All the best.

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