InnoDB Cluster

MySQL InnoDB Cluster combines three components into a fully managed HA solution:

Group Replication — synchronous multi-master replication with automatic failover
MySQL Shell (mysqlsh) — orchestrates cluster bootstrapping and management
MySQL Router — transparent connection routing that directs reads/writes to the right node

dbdeployer automates the entire setup. You get a working cluster with a router in one command.

Minimum version: MySQL 8.0+

Requirements

Before deploying, ensure the following are installed and in your PATH:

mysqlsh (MySQL Shell) — required for cluster bootstrapping
mysqlrouter (MySQL Router) — required unless you use --skip-router

which mysqlsh mysqlrouter
mysqlsh --version
mysqlrouter --version

Deploy an InnoDB Cluster

dbdeployer deploy replication 8.4.8 --topology=innodb-cluster

This bootstraps a 3-node Group Replication cluster via MySQL Shell, then starts MySQL Router pointed at it.

~/sandboxes/ic_msb_8_4_8/
├── node1/          # GR node (primary)
├── node2/          # GR node (secondary)
├── node3/          # GR node (secondary)
├── router/         # MySQL Router instance
│   ├── router_start
│   ├── router_stop
│   └── router.conf
├── check_cluster
├── start_all
├── stop_all
└── use_all

MySQL Router Ports

Port	Purpose
6446	Read/Write — routes to the current primary
6447	Read-Only — routes to secondaries (round-robin)

Connect through the router:

# Writes (goes to primary)
mysql -h 127.0.0.1 -P 6446 -u msandbox -pmsandbox

# Reads (goes to a secondary)
mysql -h 127.0.0.1 -P 6447 -u msandbox -pmsandbox

Deploy Without MySQL Router

If you don’t have MySQL Router installed, or want to manage routing yourself:

dbdeployer deploy replication 8.4.8 --topology=innodb-cluster --skip-router

No router/ directory is created. Nodes are still bootstrapped as a Group Replication cluster via MySQL Shell.

Deploy with ProxySQL Instead of MySQL Router

ProxySQL can serve as the connection router for InnoDB Cluster:

dbdeployer deploy replication 8.4.8 --topology=innodb-cluster \
    --skip-router \
    --with-proxysql

ProxySQL is deployed alongside the cluster and configured with the cluster nodes as backends.

For a comparison of MySQL Router vs ProxySQL for InnoDB Cluster routing, see Topology reference.

Checking Cluster Status

~/sandboxes/ic_msb_8_4_8/check_cluster
# Cluster members:
# node1:3310  PRIMARY   ONLINE
# node2:3320  SECONDARY ONLINE
# node3:3330  SECONDARY ONLINE

Or query the cluster via MySQL Shell:

~/sandboxes/ic_msb_8_4_8/n1 -e \
  "SELECT member_host, member_port, member_role, member_state
   FROM performance_schema.replication_group_members"

Router Management

# Start router
~/sandboxes/ic_msb_8_4_8/router/router_start

# Stop router
~/sandboxes/ic_msb_8_4_8/router/router_stop

Available Scripts

Script	Purpose
`n1`, `n2`, `n3`	Connect to cluster node 1, 2, 3
`check_cluster`	Show cluster member status and roles
`start_all` / `stop_all`	Start or stop all cluster nodes
`use_all`	Run a query on every node
`router/router_start`	Start the MySQL Router
`router/router_stop`	Stop the MySQL Router