Managing MySQL cluster hosts
You can add and remove cluster hosts and manage their settings. To move cluster hosts to a different availability zone, read this guide.
Getting a list of cluster hosts
- Go to the folder page
and select Managed Service for MySQL. - Click the cluster name and select the Hosts tab.
If you do not have the Yandex Cloud command line interface yet, install and initialize it.
The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name
or --folder-id
parameter.
To get a list of cluster hosts, run the command:
yc managed-mysql host list \
--cluster-name=<cluster_name>
Result:
+----------------------------+----------------------+---------+--------+---------------+
| NAME | CLUSTER ID | ROLE | HEALTH | ZONE ID |
+----------------------------+----------------------+---------+--------+---------------+
| rc1b...mdb.yandexcloud.net | c9q5k4ve7ev4******** | MASTER | ALIVE | ru-central1-b |
| rc1a...mdb.yandexcloud.net | c9q5k4ve7ev4******** | REPLICA | ALIVE | ru-central1-a |
+----------------------------+----------------------+---------+--------+---------------+
You can request the cluster name with a list of clusters in the folder.
To get a list of cluster hosts, use the listHosts REST API method for the Cluster resource or the ClusterService/ListHosts gRPC API call and provide the cluster ID in the clusterId
request parameter.
To find out the cluster ID, get a list of clusters in the folder.
Adding a host
The number of hosts in Managed Service for MySQL clusters is limited by the CPU and RAM quotas available to DB clusters in your cloud. To check the resources in use, open the Quotas
-
Go to the folder page
and select Managed Service for MySQL. -
Click the cluster name and go to the Hosts tab.
-
Click Add host.
-
Specify the host parameters:
-
Availability zone.
-
Subnet (if the required subnet is not on the list, create it).
-
Select Public access if the host must be accessible from outside Yandex Cloud.
-
Priority for assigning the host as a master.
-
Host priority as a MySQL replica for creating backups.
-
If you do not have the Yandex Cloud command line interface yet, install and initialize it.
The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name
or --folder-id
parameter.
To add a host to a cluster:
-
Request a list of cluster subnets to select one for the new host:
yc vpc subnet list
Result:
+----------------------+-----------+-----------------------+---------------+------------------+ | ID | NAME | NETWORK ID | ZONE | RANGE | +----------------------+-----------+-----------------------+---------------+------------------+ | b0cl69a2b4c6******** | default-d | enp6rq72rndgr******** | ru-central1-d | [172.**.*.*/20] | | e2lkj9qwe762******** | default-b | enp6rq72rndgr******** | ru-central1-b | [10.**.*.*/16] | | e9b0ph42bn96******** | a-2 | enp6rq72rndgr******** | ru-central1-a | [172.**.**.*/20] | | e9b9v22r88io******** | default-a | enp6rq72rndgr******** | ru-central1-a | [172.**.**.*/20] | +----------------------+-----------+-----------------------+---------------+------------------+
If the required subnet is not in the list, create it.
-
View a description of the CLI command for adding a host:
yc managed-mysql host add --help
-
Run the add host command (the example does not show all the available parameters):
yc managed-mysql host add \ --cluster-name=<cluster_name> \ --host zone-id=<availability_zone_ID>,` `subnet-id=<subnet_ID>,` `assign-public-ip=<public_access_to_subcluster_host>,` `replication-source=<source_host_name>,` `backup-priority=<host_backup_priority>,` `priority=<priority_of_assigning_host_as_master>
Where:
--cluster-name
: Name of a Managed Service for MySQL cluster.--host
: Host parameters:zone-id
: Availability zone.subnet-id
: Subnet ID. Specify if two or more subnets are created in the selected availability zone.assign-public-ip
: Internet access to the host,true
orfalse.
replication-source
: Replication source for the host.backup-priority
: Host backup priority, between0
and100
.priority
: Priority for assigning the host as master if the primary master fails, between0
and100
.
You can request the cluster name with a list of clusters in the folder.
-
Open the current Terraform configuration file with an infrastructure plan.
For more information about creating this file, see Creating a MySQL cluster.
-
Add a
host
block to the Managed Service for MySQL cluster description.resource "yandex_mdb_mysql_cluster" "<cluster_name>" { ... host { zone = "<availability_zone>" subnet_id = <subnet_ID> assign_public_ip = <public_access_to_host> priority = <priority_of_assigning_host_as_master> ... } }
Where:
assign_public_ip
: Public access to the host,true
orfalse
.priority
: Priority of assigning the host as master, between0
and100
.
-
Make sure the settings are correct.
-
Using the command line, navigate to the folder that contains the up-to-date Terraform configuration files with an infrastructure plan.
-
Run the command:
terraform validate
If there are errors in the configuration files, Terraform will point to them.
-
-
Confirm updating the resources.
-
Run the command to view planned changes:
terraform plan
If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
-
If you are happy with the planned changes, apply them:
-
Run the command:
terraform apply
-
Confirm the update of resources.
-
Wait for the operation to complete.
-
-
For more information, see the Terraform provider documentation
Time limits
A Terraform provider sets the timeout for Managed Service for MySQL cluster operations:
- Creating a cluster, including by restoring one from a backup: 15 minutes.
- Editing a cluster, including the MySQL version update: 60 minutes.
- Deleting a cluster: 15 minutes.
Operations exceeding the set timeout are interrupted.
Add the timeouts
block to the cluster description, for example:
resource "yandex_mdb_mysql_cluster" "<cluster_name>" {
...
timeouts {
create = "1h30m" # 1 hour 30 minutes
update = "2h" # 2 hours
delete = "30m" # 30 minutes
}
}
To add a host, use the addHosts REST API method for the Cluster resource or the ClusterService/AddHosts gRPC API call and provide the following in the request:
- Cluster ID in the
clusterId
parameter. To find out the cluster ID, get a list of clusters in the folder. - New host settings in one or more
hostSpecs
parameters.
Warning
If you cannot connect to the added host, check that the cluster security group is configured correctly for the subnet where you placed the host.
Changing a host
For each host in a Managed Service for MySQL cluster, you can:
- Setting the replication source.
- Managing public access.
- Setting backup priority.
- Set a priority for assigning the host as a master if the primary master fails.
Note
You cannot restart a separate cluster host. To restart hosts, stop and restart the cluster.
To change the parameters of the cluster host:
- Go to the folder page
and select Managed Service for MySQL. - Click the cluster name and open the Hosts tab.
- Click the
icon in the required host row and select Edit. - Set new settings for the host:
- Select a replication source for the host to control replication threads manually.
- Enable Public access if the host must be accessible from outside Yandex Cloud.
- Set the value of the Master priority field.
- Set the value of the Backup priority field.
- Click Save.
If you do not have the Yandex Cloud command line interface yet, install and initialize it.
The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name
or --folder-id
parameter.
To modify host parameters, execute the command below (the parameter list in the example is not exhaustive):
yc managed-mysql host update <host_name> \
--cluster-name=<cluster_name> \
--replication-source=<source_host_name> \
--assign-public-ip=<public_access_to_host> \
--backup-priority=<host_backup_priority> \
--priority=<priority_of_assigning_host_as_master>
Where:
--cluster-name
: Name of a Managed Service for MySQL cluster.--replication-source
: Replication source for the host.--assign-public-ip
: Internet access to the host,true
orfalse
.--backup-priority
: Host backup priority, between0
and100
.priority
: Priority of assigning the host as master if the primary master host fails, between0
and100
.
You can request the host name with a list of cluster hosts, and the cluster name, with a list of clusters in the folder.
To change the parameters of the cluster host:
-
Open the current Terraform configuration file with an infrastructure plan.
For more information about creating this file, see Creating a MySQL cluster.
-
In the Managed Service for MySQL cluster description, change the attributes of the
host
block corresponding to the host to update.resource "yandex_mdb_mysql_cluster" "<cluster_name>" { ... host { replication_source_name = "<replication_source>" assign_public_ip = <public_access_to_host> priority = <priority_of_assigning_host_as_master> } }
Where:
assign_public_ip
: Public access to the host,true
orfalse
.priority
: Priority of assigning the host as master, between0
and100
.
-
Make sure the settings are correct.
-
Using the command line, navigate to the folder that contains the up-to-date Terraform configuration files with an infrastructure plan.
-
Run the command:
terraform validate
If there are errors in the configuration files, Terraform will point to them.
-
-
Confirm updating the resources.
-
Run the command to view planned changes:
terraform plan
If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
-
If you are happy with the planned changes, apply them:
-
Run the command:
terraform apply
-
Confirm the update of resources.
-
Wait for the operation to complete.
-
-
For more information, see the Terraform provider documentation
Time limits
A Terraform provider sets the timeout for Managed Service for MySQL cluster operations:
- Creating a cluster, including by restoring one from a backup: 15 minutes.
- Editing a cluster, including the MySQL version update: 60 minutes.
- Deleting a cluster: 15 minutes.
Operations exceeding the set timeout are interrupted.
Add the timeouts
block to the cluster description, for example:
resource "yandex_mdb_mysql_cluster" "<cluster_name>" {
...
timeouts {
create = "1h30m" # 1 hour 30 minutes
update = "2h" # 2 hours
delete = "30m" # 30 minutes
}
}
To update host parameters, use the updateHosts REST API method for the Cluster resource or the ClusterService/UpdateHosts gRPC API call and provide the following in the request:
-
Cluster ID in the
clusterId
parameter. To find out the cluster ID, get a list of clusters in the folder. -
Configuration array for hosts to update in the
updateHostsSpecs
parameter.For each host, specify:
- Name in the
hostName
field. - List of settings to update, in the
updateMask
parameter.
- Name in the
Warning
This API method overrides all parameters of the object being modified that were not explicitly passed in the request to the default values. To avoid this, list the settings you want to change in the updateMask
parameter (one line separated by commas).
Warning
If you can't connect to the changed host, check that the cluster's security group is configured correctly for the subnet where you placed the host.
Removing a host
You can remove a host from a MySQL cluster if it is not the only host in it. To replace a single host, first create a new host and then remove the old one.
If the host is the master when deleted, Managed Service for MySQL automatically assigns the next highest-priority replica as the master.
- Go to the folder page
and select Managed Service for MySQL. - Click the cluster name and open the Hosts tab.
- Click the
icon in the required host row and select Delete.
If you do not have the Yandex Cloud command line interface yet, install and initialize it.
The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name
or --folder-id
parameter.
To remove a host from the cluster, run:
yc managed-mysql host delete <host_name> \
--cluster-name=<cluster_name>
You can request the host name with a list of cluster hosts, and the cluster name, with a list of clusters in the folder.
-
Open the current Terraform configuration file with an infrastructure plan.
For more information about creating this file, see Creating a MySQL cluster.
-
Delete the
host
block from the Managed Service for MySQL cluster description. -
Make sure the settings are correct.
-
Using the command line, navigate to the folder that contains the up-to-date Terraform configuration files with an infrastructure plan.
-
Run the command:
terraform validate
If there are errors in the configuration files, Terraform will point to them.
-
-
Type
yes
and press Enter.-
Run the command to view planned changes:
terraform plan
If the resource configuration descriptions are correct, the terminal will display a list of the resources to modify and their parameters. This is a test step. No resources are updated.
-
If you are happy with the planned changes, apply them:
-
Run the command:
terraform apply
-
Confirm the update of resources.
-
Wait for the operation to complete.
-
-
For more information, see the Terraform provider documentation
Time limits
A Terraform provider sets the timeout for Managed Service for MySQL cluster operations:
- Creating a cluster, including by restoring one from a backup: 15 minutes.
- Editing a cluster, including the MySQL version update: 60 minutes.
- Deleting a cluster: 15 minutes.
Operations exceeding the set timeout are interrupted.
Add the timeouts
block to the cluster description, for example:
resource "yandex_mdb_mysql_cluster" "<cluster_name>" {
...
timeouts {
create = "1h30m" # 1 hour 30 minutes
update = "2h" # 2 hours
delete = "30m" # 30 minutes
}
}
To delete a host, use the deleteHosts REST API method for the Cluster resource or the ClusterService/DeleteHosts gRPC API call and provide the following in the request:
- Cluster ID in the
clusterId
parameter. To find out the cluster ID, get a list of clusters in the folder. - Name(s) of the host(s) to delete in the
hostNames
parameter.