Loading data from Yandex Object Storage to a ClickHouse® data mart
You can migrate data from Yandex Object Storage to the Managed Service for ClickHouse® table using Data Transfer. To do this:
If you no longer need the resources you created, delete them.
Getting started
Prepare the infrastructure:
-
Create a Managed Service for ClickHouse® target cluster in any suitable configuration with the following settings:
- Number of ClickHouse® hosts: At least two, which is required to enable replication in the cluster.
- Public access to cluster hosts: Allowed
- DB name:
db1
- Username:
user1
- Password:
<user_password>
-
If using security groups in your cluster, make sure they are configured correctly and allow connecting to the cluster.
-
Create a service account named
storage-viewer
with thestorage.viewer
role. The transfer will use it to access the bucket. -
Create a static access key for the
storage-viewer
service account.
-
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 object-storage-to-clickhouse.tf
configuration file to the same working directory.This file describes:
- Network.
- Subnet.
- Security group required to connect to a cluster.
- Service account to be used to create and access the bucket.
- Yandex Lockbox secret which will store the static key of the service account to configure the source endpoint.
- Object Storage source bucket.
- Managed Service for ClickHouse® target cluster.
- Target endpoint.
- Transfer.
-
Specify the following in the
object-storage-to-clickhouse.tf
file:folder_id
: Cloud folder ID, same as in the provider settings.bucket_name
: Bucket name consistent with the naming conventions.ch_password
: ClickHouse® user password.
-
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 test data
-
Prepare two CSV files with test data:
-
demo_data1.csv
:1,Anna 2,Robert 3,Umar 4,Algul 5,Viktor
-
demo_data2.csv
:6,Maria 7,Alex
-
-
Upload the
demo_data1.csv
file to the Object Storage bucket.
Prepare and activate the transfer
-
Create a source endpoint of the
Object Storage
type with the following settings:-
Database type:
Object Storage
-
Bucket: Bucket name in Object Storage
-
Access Key ID: Public part of the service account static key. If you created your infrastructure with Terraform, copy the key value from the Yandex Lockbox secret.
-
Secret Access Key: Private part of the service account static key. If you created your infrastructure with Terraform, copy the key value from the Yandex Lockbox secret.
-
Endpoint:
https://storage.yandexcloud.net
-
Region:
ru-central1
-
Data format:
CSV
-
Delimiter: Comma (
,
) -
Table:
table1
-
Result table schema: Select
Manual
and specify field names and data types:Id
:Int64
Name
:UTF8
Leave the default values for other properties.
-
-
Create a target endpoint and a transfer:
ManuallyUsing Terraform-
Create a target endpoint of the
ClickHouse®
type and specify the cluster connection parameters in it:- Connection type:
Managed cluster
- Managed cluster:
<ClickHouse®_target_cluster_name>
from the drop-down list - Database:
db1
- User:
user1
- Password:
<user_password>
- Connection type:
-
Create a transfer of the Snapshot and replication type that will use the created endpoints.
-
Activate the transfer and wait for its status to change to Replicating.
-
In the
object-storage-to-clickhouse.tf
file, specify the following parameters:source_endpoint_id
: Source endpoint ID.transfer_enabled
:1
to create a transfer.
-
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.
-
-
-
The transfer will be activated automatically. Wait for its status to change to Replicating.
-
Test the transfer
Check the transfer performance by testing the copy and replication processes.
Test the copy process
-
Connect to
db1
in the Managed Service for ClickHouse® target cluster. -
Run the following query:
SELECT * FROM db1.table1;
Response example
__file_name | __row_index | Id | Name --------------+-------------+----+-------- demo_data1.csv | 1 | 1 | Anna demo_data1.csv | 2 | 2 | Robert demo_data1.csv | 3 | 3 | Umar demo_data1.csv | 4 | 4 | Algul demo_data1.csv | 5 | 5 | Viktor
Test the replication process
-
Upload the
demo_data2.csv
file to the Object Storage bucket. -
Make sure the data from
demo_data2.csv
has been added to the target database:-
Connect to
db1
in the Managed Service for ClickHouse® target cluster. -
Run the following query:
SELECT * FROM db1.table1;
Response example
__file_name | __row_index | Id | Name --------------+-------------+----+-------- demo_data1.csv | 1 | 1 | Anna demo_data1.csv | 2 | 2 | Robert demo_data1.csv | 3 | 3 | Umar demo_data1.csv | 4 | 4 | Algul demo_data1.csv | 5 | 5 | Viktor demo_data2.csv | 1 | 6 | Maria demo_data2.csv | 2 | 7 | Alex
-
Delete the resources you created
Note
Before deleting the created resources, deactivate the transfer.
Some resources are not free of charge. To avoid paying for them, delete the resources you no longer need:
-
Delete the other resources depending on how they were created:
ManuallyUsing TerraformIf you created your resources using Terraform:
-
Delete all objects from the bucket.
-
In the terminal window, go to the directory containing the infrastructure plan.
-
Delete the
object-storage-to-clickhouse.tf
configuration file. -
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.
-
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.
-
All the resources described in the
object-storage-to-clickhouse.tf
configuration file will be deleted. -
-