5.6.7 The Clone Plugin

The clone plugin permits cloning data locally or from a remote MySQL server instance. Cloned data is a physical snapshot of data stored in InnoDB that includes schemas, tables, tablespaces, and data dictionary metadata. The cloned data comprises a fully functional data directory, which permits using the clone plugin for MySQL server provisioning.

A local cloning operation clones data from the MySQL server instance where the cloning operation is initiated to a directory on the same server or node where MySQL server instance runs.

Figure 5.1 Local Cloning Operation

A remote cloning operation involves a local MySQL server instance (the “recipient”) where the cloning operation is initiated, and a remote MySQL server instance (the “donor”) where the source data is located. When a remote cloning operation is initiated on the recipient, cloned data is transferred over the network from the donor to the recipient. By default, a remote cloning operation removes the data in the recipient data directory and replaces it with the cloned data. Optionally, you can clone data to a different directory on the recipient to avoid removing existing data.

Figure 5.2 Remote Cloning Operation

There is no difference with respect to data that is cloned by a local cloning operation as compared to a remote cloning operation. Both operations clone the same data.

The clone plugin supports replication. In addition to cloning data, a cloning operation extracts and transfers replication coordinates from the donor and applies them on the recipient, which enables using the clone plugin for provisioning Group Replication members and replication slaves. Using the clone plugin for provisioning is considerably faster and more efficient than replicating a large number of transactions (see Section 5.6.7.6, “Cloning for Replication”). Group Replication members can also be configured to use the clone plugin as an alternative method of recovery, so that members automatically choose the most efficient way to retrieve group data from seed members. For more information, see Section 18.4.3.1, “Cloning for Distributed Recovery”.

The clone plugin supports cloning of encrypted and page-compressed data. See Section 5.6.7.4, “Cloning Encrypted Data”, and Section 5.6.7.5, “Cloning Compressed Data”.

The clone plugin must be installed before you can use it. For installation instructions, see Section 5.6.7.1, “Installing the Clone Plugin”. For cloning instructions, see Section 5.6.7.2, “Cloning Data Locally”, and Section 5.6.7.3, “Cloning Remote Data”.

Performance Schema tables and instrumentation are provided for monitoring cloning operations. See Section 5.6.7.9, “Monitoring Cloning Operations”.