---
title: "Link a MySQL semi-sync cluster to a dedicated server"
sidebar_label: "Link a cluster to a dedicated server"
sidebar_position: 15
description: "How to link a MySQL semi-sync cluster to a dedicated server"
---
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# Link a MySQL semi-sync cluster to a dedicated server
:::info
Some dedicated server configurations of the [Chipcore Line](/dedicated/order/dedicated-configurations.mdx#prebuilt-servers) cannot be added to a global router network because they lack a port for connecting to a private network. You can check for the presence of a private network port in the [Control panel](https://my.selectel.ru/servers/servers/) on the server page under the **Ports**.
:::
1. [Create a global router](#create-global-router).
2. [Connect a network and a subnet to the global router up to the dedicated server VLAN](#connect-network-and-subnet-to-router-up-to-dedicated-server-vlan).
3. [Connect a network and a subnet to the global router up to the Cloud Platform project](#connect-network-and-subnet-to-router-up-to-cloud-platform-project).
4. [Assign IP addresses from the created subnets to the dedicated server](#assign-ip-to-dedicated-server).
5. [Specify routes on the dedicated server](#write-routes-on-dedicated-server).
6. [Create a Managed Database cluster](#create-managed-database-cluster): new or from a backup of an existing Managed Database cluster.
See an [example of networking](#example-of-network-organization-between-managed-database-and-dedicated-server) between a dedicated server and a Managed Database.
## Example of networking between a Managed Database and a dedicated server \{#example-of-network-organization-between-managed-database-and-dedicated-server}
If you need to configure private connectivity between a dedicated server in the SPB-2 pool and a new Managed Database in the ru-2 pool:
1. Create a global router.
2. Connect two private subnets to the router — `192.168.0.0/29` with gateway `192.168.0.1` for the SPB-2 pool and `172.16.0.0/29` with gateway `172.16.0.1` for the ru-2 pool.
3. Assign an address from the `192.168.0.0/29` subnet to the dedicated server, for example, `192.168.0.2`.
4. Specify routes on the dedicated server in the SPB-2 pool — to the `172.16.0.0/29` subnet via gateway `192.168.0.1`.
5. Create a new Managed Database cluster on the subnet `172.16.0.0/29`.
## 1. Create a global router \{#create-global-router}
## 2. Connect a network and subnet to a VLAN of a dedicated server to the global router \{#connect-network-and-subnet-to-router-up-to-dedicated-server-vlan}
## 3. Connect a network and subnet to a Cloud Platform project to the global router \{#connect-network-and-subnet-to-router-up-to-cloud-platform-project}
## 4. Assign an IP address to a dedicated server \{#assign-ip-to-dedicated-server}
Configure a local port on the dedicated server that is included in the global router network. Assign an IP address from the private subnet that you [connected to the global router in step 2](#connect-network-and-subnet-to-router-up-to-dedicated-server-vlan).
## 5. Specify a route on the dedicated server \{#write-routes-on-dedicated-server}
On the server, you must add a static route to the cloud platform subnet that you [connected to the global router in step 3](#connect-network-and-subnet-to-router-up-to-cloud-platform-project).
## 6. Create a Managed Database cluster \{#create-managed-database-cluster}
New
1. In the [Control panel](https://my.selectel.ru/vpc/default/dbaas/), in the top menu, click **Products** and select **Managed Databases**.
2. Click **Create cluster**.
3. Enter the cluster name.
4. Select a [location](/infrastructure/locations.mdx). You cannot change the location after creation.
5. Select a DBMS — MySQL semi-sync.
6. Select a [MySQL semi-sync version](/managed-databases/mysql-semi-sync/configurations.mdx#versions). You cannot change the version after creation.
7. Select a [configuration line](/managed-databases/mysql-semi-sync/configurations.mdx) and specify the number of vCPU, the amount of RAM, and the disk size.
After creating the cluster, you can change the node configuration — [scale the cluster](/managed-databases/mysql-semi-sync/resize-cluster.mdx).
8. Optional: to configure [cluster fault tolerance](/managed-databases/mysql-semi-sync/cluster-fault-tolerance.mdx), specify the number of nodes in the cluster in the **Fault Tolerance** block. The first node is the master node, the others are replicas. For a multi-node cluster, the [SLA](https://files.selectel.ru/docs/ru/conditions-cloud-platform.pdf) applies — we guarantee 99.95% write availability and 99.99% read availability.
9. Select the subnet that you [connected to the global router to the Cloud Platform project](#connect-network-and-subnet-to-router-up-to-cloud-platform-project).
You can [restrict the list of addresses](/managed-databases/mysql-semi-sync/network-access-control.mdx) from which access to the database cluster will be allowed.
10. Optional: to change the [DBMS settings](/managed-databases/mysql-semi-sync/settings.mdx), click **Change**. We recommend changing settings only when necessary — incorrectly selected values can reduce cluster performance.
11. Check the cluster price.
12. Click **Create cluster**. The cluster will be ready to use when it enters the `ACTIVE`.
From backup
1. In the [Control panel](https://my.selectel.ru/vpc/default/dbaas/), in the top menu, click **Products** and select **Managed Databases**.
2. Click **Create cluster**.
3. Select the [location](/infrastructure/locations.mdx) that hosts your existing Managed Database cluster.
4. Select the **Restore cluster from backup**.
5. Select an existing Managed Database cluster.
6. Choose how to restore the cluster — from the latest available backup or to a specific point in time within the last 7 days.
7. Click **Continue**.
8. Select a [configuration line](/managed-databases/mysql-semi-sync/configurations.mdx#configuration-lines) and specify the number of vCPU, the amount of RAM, and the disk size.
After creating the cluster, you can change the node configuration — [scale the cluster](/managed-databases/mysql-semi-sync/resize-cluster.mdx).
9. Optional: to configure cluster fault tolerance, specify the number of nodes in the cluster in the **Fault Tolerance** block. The first node is the master node, the others are replicas. For a multi-node cluster, the [SLA](https://files.selectel.ru/docs/ru/conditions-cloud-platform.pdf) applies — we guarantee 99.95% write availability and 99.99% read availability.
10. Select the subnet that you [connected to the global router to the Cloud Platform project](#connect-network-and-subnet-to-router-up-to-cloud-platform-project).
You can [restrict the list of addresses](/managed-databases/mysql-semi-sync/network-access-control.mdx) from which access to the database cluster will be allowed.
11. Optional: to change [DBMS settings](/managed-databases/mysql-semi-sync/settings.mdx), click **Change**. We recommend changing settings only when necessary — incorrectly selected values can reduce cluster performance.
12. Check the cluster price.
13. Click **Create cluster**.
14. After restoring the cluster, the node addresses will change — update them in your application.