How to set up a three-node cluster on a single box

This tutorial describes how to set up a 3-node cluster on a single physical box.

For the purposes of this tutorial, assume the following:

• The local IP address is 192.168.2.21.

• Percona XtraDB Cluster is extracted from binary tarball into /usr/local/Percona-XtraDB-Cluster-8.0.x86_64

To set up the cluster:

1. Create three MySQL configuration files for the corresponding nodes:

   • /etc/my.4000.cnf

   [mysqld]
   port = 4000
   socket=/tmp/mysql.4000.sock
   datadir=/data/bench/d1
   basedir=/usr/local/Percona-XtraDB-Cluster-8.0.x86_64
   user=mysql
   log_error=error.log
   wsrep_cluster_address='gcomm://192.168.2.21:5030,192.168.2.21:6030'
   wsrep_provider=/usr/local/Percona-XtraDB-Cluster-8.0.x86_64/lib/libgalera_smm.so
   wsrep_sst_receive_address=192.168.2.21:4020
   wsrep_node_incoming_address=192.168.2.21
   wsrep_cluster_name=trimethylxanthine
   wsrep_provider_options = "gmcast.listen_addr=tcp://192.168.2.21:4030;"
   wsrep_sst_method=xtrabackup-v2
   wsrep_node_name=node4000
   innodb_autoinc_lock_mode=2
   

   • /etc/my.5000.cnf

   [mysqld]
   port = 5000
   socket=/tmp/mysql.5000.sock
   datadir=/data/bench/d2
   basedir=/usr/local/Percona-XtraDB-Cluster-8.0.x86_64
   user=mysql
   log_error=error.log
   wsrep_cluster_address='gcomm://192.168.2.21:4030,192.168.2.21:6030'
   wsrep_provider=/usr/local/Percona-XtraDB-Cluster-8.0.x86_64/lib/libgalera_smm.so
   wsrep_sst_receive_address=192.168.2.21:5020
   wsrep_node_incoming_address=192.168.2.21
   
   wsrep_cluster_name=trimethylxanthine
   wsrep_provider_options = "gmcast.listen_addr=tcp://192.168.2.21:5030;"
   wsrep_sst_method=xtrabackup-v2
   wsrep_node_name=node5000
   innodb_autoinc_lock_mode=2
   

   • /etc/my.6000.cnf

   [mysqld]
   port = 6000
   socket=/tmp/mysql.6000.sock
   datadir=/data/bench/d3
   basedir=/usr/local/Percona-XtraDB-Cluster-8.0.x86_64
   user=mysql
   log_error=error.log
   wsrep_cluster_address='gcomm://192.168.2.21:4030,192.168.2.21:5030'
   wsrep_provider=/usr/local/Percona-XtraDB-Cluster-8.0.x86_64/lib/libgalera_smm.so
   wsrep_sst_receive_address=192.168.2.21:6020
   wsrep_node_incoming_address=192.168.2.21
   wsrep_cluster_name=trimethylxanthine
   wsrep_provider_options = "gmcast.listen_addr=tcp://192.168.2.21:6030;"
   wsrep_sst_method=xtrabackup-v2
   wsrep_node_name=node6000
   innodb_autoinc_lock_mode=2
   

2. Create three data directories for the nodes:

   • /data/bench/d1

   • /data/bench/d2

   • /data/bench/d3

3. Start the first node using the following command (from the Percona XtraDB Cluster install directory):

   $ bin/mysqld_safe --defaults-file=/etc/my.4000.cnf --wsrep-new-cluster
   

   If the node starts correctly, you should see the following output:

   Expected output

   111215 19:01:49 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 0)
   111215 19:01:49 [Note] WSREP: New cluster view: global state: 4c286ccc-2792-11e1-0800-94bd91e32efa:0, view# 1: Primary, number of nodes: 1, my index: 0, protocol version 1
   

   To check the ports, run the following command:

   $ netstat -anp | grep mysqld
   tcp        0      0 192.168.2.21:4030           0.0.0.0:*                   LISTEN      21895/mysqld
   tcp        0      0 0.0.0.0:4000                0.0.0.0:*                   LISTEN      21895/mysqld
   

4. Start the second and third nodes:

   bin/mysqld_safe --defaults-file=/etc/my.5000.cnf
   bin/mysqld_safe --defaults-file=/etc/my.6000.cnf
   

   If the nodes start and join the cluster successful, you should see the following output:

   111215 19:22:26 [Note] WSREP: Shifting JOINER -> JOINED (TO: 2)
   111215 19:22:26 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 2)
   111215 19:22:26 [Note] WSREP: Synchronized with group, ready for connections
   

   To check the cluster size, run the following command:

   $ mysql -h127.0.0.1 -P6000 -e "show global status like 'wsrep_cluster_size';"
   

   Expected output

   +--------------------+-------+
   | Variable_name      | Value |
   +--------------------+-------+
   | wsrep_cluster_size | 3     |
   +--------------------+-------+
   

   After that you can connect to any node and perform queries, which will be automatically synchronized with other nodes. For example, to create a database on the second node, you can run the following command:

   $ mysql -h127.0.0.1 -P5000 -e "CREATE DATABASE hello_peter"