Migrating data from PostgreSQL to YDB
A Managed Service for YDB cluster can get data from PostgreSQL databases in real time. This data is automatically added to YDB tables with names of source schemas and tables.
To run data delivery:
If you no longer need the resources you created, delete them.
Getting started
Prepare the data transfer infrastructure:
- Create a source Managed Service for PostgreSQL cluster in any applicable configuration with publicly available hosts.
- Create a Managed Service for YDB database in any suitable configuration.
- In the source cluster, create a user and assign to them the
mdb_replication
role.
-
If you do not have Terraform yet, install it.
-
Get the authentication credentials. You can add them to environment variables or specify them later in the provider configuration file.
-
Configure and initialize a provider. There is no need to create a provider configuration file manually, you can download it
. -
Place the configuration file in a separate working directory and specify the parameter values. If you did not add the authentication credentials to environment variables, specify them in the configuration file.
-
Download the data-transfer-mpg-ydb.tf
configuration file to the same working directory.This file describes:
- Network.
- Subnet.
- Security group and the rule required to connect to a Managed Service for PostgreSQL cluster.
- Managed Service for PostgreSQL source cluster.
- PostgreSQL database.
- Managed Service for PostgreSQL user.
- Managed Service for YDB database.
- Source endpoint.
- Transfer.
-
In the
data-transfer-mpg-ydb.tf
file, specify the values of parameters:source_pg_version
: PostgreSQL version in the source cluster.source_db_name
: DB name in the source cluster.source_user_name
: Username for establishing a connection to the source cluster.source_user_password
: User password.target_db_name
: Managed Service for YDB database name.transfer_enabled
: Set0
to ensure that no transfer and source endpoint is created before you manually create a target endpoint.
-
Make sure the Terraform configuration files are correct using this command:
terraform validate
If there are any errors in the configuration files, Terraform will point them out.
-
Create the required infrastructure:
-
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.
-
All the required resources will be created in the specified folder. You can check resource availability and their settings in the management console
. -
Prepare the source cluster
-
Connect to the database of the source cluster on behalf of the new user.
-
Add test data to the database. In this example, a simple table with information from car sensors is used.
Create a table:
CREATE TABLE public.sensors ( "device_id" text PRIMARY KEY NOT NULL, "datetime" timestamp NOT NULL, "latitude" real NOT NULL, "longitude" real NOT NULL, "altitude" real NOT NULL, "speed" real NOT NULL, "battery_voltage" real, "cabin_temperature" real NOT NULL, "fuel_level" real );
Populate the table with data:
INSERT INTO public.sensors VALUES ('iv9a94th6rzt********', '2020-06-05 17:27:00', 55.70329032, 37.65472196, 427.5, 0, 23.5, 17, NULL), ('rhibbh3y08qm********', '2020-06-06 09:49:54', 55.71294467, 37.66542005, 429.13, 55.5, NULL, 18, 32), ('iv9a94th678t********', '2020-06-07 15:00:10', 55.70985913, 37.62141918, 417.0, 15.7, 10.3, 17, NULL);
Prepare and activate the transfer
-
-
Database type:
YDB
. -
Endpoint parameters:
- Connection settings:
- Database: Select the Managed Service for YDB database from the list.
- Service account ID: Select or create a service account with the
ydb.editor
role.
- Connection settings:
-
-
Create a source endpoint and transfer:
ManuallyTerraform-
Create an endpoint for the previously created PostgreSQL source with the following settings:
- Database type:
PostgreSQL
. - Endpoint parameters:
- Installation type:
Managed Service for PostgreSQL cluster
. - Managed Service for PostgreSQL cluster: Created Managed Service for PostgreSQL cluster.
- Database: Name of the DB created in the cluster Managed Service for PostgreSQL.
- User: Name of the user created in the Managed Service for PostgreSQL cluster.
- Password: User password.
- Included tables:
<DB_name>.sensors
.
- Installation type:
- Database type:
-
Create a transfer of the Snapshot and replication type that will use the created endpoints.
-
Activate the transfer.
-
In the
data-transfer-mpg-ydb.tf
file, specify the values of parameters:target_endpoint_id
: ID of the target endpoint.transfer_enabled
: For creating a source endpoint and a transfer, the value is1
.
-
Make sure the Terraform configuration files are correct using this command:
terraform validate
If there are any errors in the configuration files, Terraform will point them out.
-
Create the required infrastructure:
-
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.
-
Once created, your transfer will be activated automatically.
-
-
Test the transfer
-
Wait for the transfer status to change to Replicating.
-
Make sure the data from the source Managed Service for PostgreSQL cluster has been moved to the Managed Service for YDB database:
Management console- In the management console
, select the folder with the DB you need. - In the list of services, select Managed Service for YDB.
- Select the database from the list.
- Go to the Navigation tab.
- Check that the Managed Service for YDB database contains the
public_sensors
table with the test data.
- In the management console
-
Connect to the Managed Service for PostgreSQL source cluster and add data to the
measurements
table:INSERT INTO public.sensors VALUES ('iv7b74th678t********', '2020-06-08 17:45:00', 53.70987913, 36.62549834, 378.0, 20.5, 5.3, 20, NULL);
-
Check that the Managed Service for YDB database shows information about the added row:
Management consoleYDB CLI- In the management console
, select the folder with the DB you need. - In the list of services, select Managed Service for YDB.
- Select the database from the list.
- Go to the Navigation tab.
- Check that new data has been added to the
public_sensors
table.
-
Check that new data has been added to the
public_sensors
table:ydb table query execute \ --query "SELECT * \ FROM public_sensors"
- In the management console
Delete the resources you created
Some resources are not free of charge. To avoid paying for them, delete the resources you no longer need:
- Deactivate and delete the transfer.
- Delete endpoints for the source and target.
- If you created a service account together with the target endpoint, delete it.
- Delete the Managed Service for YDB database.
- Delete the Managed Service for PostgreSQL cluster.
-
In the terminal, go to the working directory that contains the
data-transfer-mpg-ydb.tf
configuration file. -
Delete the resources using this command:
terraform destroy
-
Type
yes
and press Enter.All the resources described in the
data-transfer-mpg-ydb.tf
configuration file will be deleted.