mysql-ch-replicator 0.0.4

Tool for replication of MySQL databases to ClickHouse

mysql_ch_replicator

mysql_ch_replicator is a powerful and efficient tool designed for real-time replication of MySQL databases to ClickHouse.

With a focus on high performance, it utilizes batching heavily and uses C++ extension for faster execution. This tool ensures seamless data integration with support for migrations, schema changes, and correct data management.

Features

• Real-Time Replication: Keeps your ClickHouse database in sync with MySQL in real-time.
• High Performance: Utilizes batching and ports slow parts to C++ (e.g., MySQL internal JSON parsing) for optimal performance.
• Supports Migrations/Schema Changes: Handles adding, altering, and removing tables without breaking the replication process.
• Recovery without Downtime: Allows for preserving old data while performing initial replication, ensuring continuous operation.
• Correct Data Removal: Unlike MaterializedMySQL, mysql_ch_replicator ensures physical removal of data.
• Comprehensive Data Type Support: Accurately replicates most data types, including JSON, booleans, and more. Easily extensible for additional data types.
• Multi-Database Handling: Replicates the binary log once for all databases, optimizing the process compared to MaterializedMySQL, which replicates the log separately for each database.

Installation

To install mysql_ch_replicator, use the following command:

pip install mysql_ch_replicator

You may need to also compile C++ components if they're not pre-built for your platform.

Usage

Basic Usage

To start the replication process:

1. Prepare config file. Use example_config.yaml as an example.
2. Start the replication:

mysql_ch_replicator --config config.yaml run_all

Configuration

mysql_ch_replicator can be configured through a configuration file. Here is the config example:

mysql:
  host: 'localhost'
  port: 8306
  user: 'root'
  password: 'root'

clickhouse:
  host: 'localhost'
  port: 8323
  user: 'default'
  password: 'default'

binlog_replicator:
  data_dir: '/home/user/binlog/'
  records_per_file: 100000

databases: 'database_name_pattern_*'

• mysql MySQL connection settings
• clickhouse ClickHouse connection settings
• binlog_replicator.data_dir Directory for store binary log and application state
• databases Databases name pattern to replicate, eg db_* will match db_1 db_2 db_test

Advanced Features

Migrations & Schema Changes

mysql_ch_replicator supports the following:

• Adding Tables: Automatically starts replicating data from newly added tables.
• Altering Tables: Adjusts replication strategy based on schema changes.
• Removing Tables: Handles removal of tables without disrupting the replication process.

Recovery Without Downtime

In case of a failure or during the initial replication, mysql_ch_replicator will preserve old data and continue syncing new data seamlessly. You could remove the state and restart replication from scratch.

Development

To contribute to mysql_ch_replicator, clone the repository and install the required dependencies:

git clone https://github.com/your-repo/mysql_ch_replicator.git
cd mysql_ch_replicator
pip install -r requirements.txt

Running Tests

For running test you will need:

1. MySQL and ClickHouse server
2. config.yaml that will be used during tests
3. Run tests with:

pytest -v -s test_mysql_ch_replicator.py

Contribution

Contributions are welcome! Please open an issue or submit a pull request for any bugs or features you would like to add.

License

mysql_ch_replicator is licensed under the MIT License. See the LICENSE file for more details.

Acknowledgements

Thank you to all the contributors who have helped build and improve this tool.