Percona XtraDB Cluster

As a DevOps activist I am exploring Percona XtraDB. In a series of blogs I will share my learnings. This blog intends to capture step by step details of installation of Percona XtraDB in Cluster mode.

Why Cluster Mode Introduction:

Percona XtraDB cluster is High Availability and Scalability solution for MySQL users which provides
Synchronous replication : Transaction either committed on all nodes or none.
Multi-master replication : You can write to any node.
Parallel applying events on slave : parallel event application on all slave nodes
Automatic node provisioning
Data consistency
Straight into the Act:Installing Percona XtraDB Cluster

Pre-requisites/Assumptions

OS – Ububtu
3 Ubuntu nodes are available

For the sake of this discussion lets name the nodes as

node 1
hostname: percona_xtradb_cluster1
IP: 192.168.1.2

node 2
hostname: percona_xtradb_cluster2
IP: 192.168.1.3

node 3
hostname: percona_xtradb_cluster3
IP: 192.168.1.4

Repeat the below steps on all nodes

STEP 1 : Add the Percona repository

$ echo "deb http://repo.percona.com/apt precise main" >> /etc/apt/sources.list.d/percona.list
$ echo "deb-src http://repo.percona.com/apt precise main" >> /etc/apt/sources.list.d/percona.list
$ apt-key adv --keyserver keys.gnupg.net --recv-keys 1C4CBDCDCD2EFD2A

STEP 2 : After adding percona repository, Update apt cache so that new packages can be included in our apt-cache.

$ apt-get update

STEP 3 : Install Percona XtraDB Cluster :

$ apt-get install -y percona-xtradb-cluster-56 qpress xtrabackup

STEP 4 : Install additional package for editing files, downloading etc :

$ apt-get install -y python-software-properties vim wget curl netcat

With the above steps we have, installed Percona XtraDB Cluster on every node. Now we’ll configure each node, so that a cluster of three nodes can be formed.

Node Configuration:

Add/Modify file /etc/mysql/my.cnf on first node :

[MYSQLD] #This section is for mysql configuration
user = mysql                                                   
default_storage_engine = InnoDB                  
basedir = /usr
datadir = /var/lib/mysql
socket = /var/run/mysqld/mysqld.sock
port = 3306
innodb_autoinc_lock_mode = 2
log_queries_not_using_indexes = 1
max_allowed_packet = 128M
binlog_format = ROW
wsrep_provider = /usr/lib/libgalera_smm.so
wsrep_node_address = 192.168.1.2
wsrep_cluster_name="newcluster"
wsrep_cluster_address = gcomm://192.168.1.2,192.168.1.3,192.168.1.4
wsrep_node_name = cluster1
wsrep_slave_threads = 4
wsrep_sst_method = xtrabackup-v2
wsrep_sst_auth = sst:secret

[sst] #This section is for sst(state snapshot transfer) configuration 
streamfmt = xbstream

[xtrabackup] #This section is defines tuning configuration for xtrabackup
compress
compact
parallel = 2
compress_threads = 2
rebuild_threads = 2

Note :
wsrep_node_address = {IP of current node}
wsrep_cluster_name= {Name of cluster}
wsrep_cluster_address = gcomm://{Comma separated IP address’s which are in cluster}
wsrep_node_name = {This is name of current node which is used to identify it in cluster}

Now as we have done node configuration. Now start first node services:
Start the node :

$ service mysql bootstrap-pxc

Make sst user for authentication of cluster nodes :

$ mysql -e "GRANT RELOAD, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'sst'@'localhost' IDENTIFIED BY 'secret';"

Check cluster status :

$ mysql -e "show global status like 'wsrep%';"

Configuration file for second node:

[MYSQLD]
user = mysql
default_storage_engine = InnoDB
basedir = /usr
datadir = /var/lib/mysql
socket = /var/run/mysqld/mysqld.sock
port = 3306
innodb_autoinc_lock_mode = 2
log_queries_not_using_indexes = 1
max_allowed_packet = 128M
binlog_format = ROW
wsrep_provider = /usr/lib/libgalera_smm.so
wsrep_node_address = 192.168.1.3
wsrep_cluster_name="newcluster"
wsrep_cluster_address = gcomm://192.168.1.2,192.168.1.3,192.168.1.4
wsrep_node_name = cluster2
wsrep_slave_threads = 4
wsrep_sst_method = xtrabackup-v2
wsrep_sst_auth = sst:secret

[sst]
streamfmt = xbstream

[xtrabackup]
compress
compact
parallel = 2

After doing configuration, start services of node 2.
Start node 2 :

$ service mysql start

Check cluster status :

$ mysql -e "show global status like 'wsrep%';"

Now similarly you have to configure node 3. Changes are listed below.

Changes in configuration for node 3 :
      wsrep_node_address = 192.168.1.4
      wsrep_node_name = cluster3

Start node 3 :

$ service mysql start

Test percona XtraDb cluster:

Log-in by mysql client in any node:

<code prettyprint="" style="color: black; word-wrap: no

mysql>create database opstree;
mysql>use opstree;
mysql>create table nu113r(name varchar(50));
mysql>insert into nu113r values("zukin");
mysql>select * from nu113r;

Check the database on other node by mysql client:

mysql>show databases;

Note : There should be a database named “opstree”.

mysql>use opstree;

mysql>select * from nu113r;

Note : Data will be same as in the previous node.

Author: opstreeblog

We try on our part to contribute to the DevSecOps knowledge pool. View all posts by opstreeblog

One thought on “Getting Started with Percona XtraDB Cluster”

Thanks for the post. I used similar post for installation – http://sysadm.pp.ua/linux/px-cluster.html . Did you made some performance tests(high load) ? Thanks in advance.

LikeLike