mysql_cdc

MySQL/MariaDB binlog replication client for Rust

Limitations

Please note the lib currently has the following limitations:

• Supports only standard auth plugins mysql_native_password and caching_sha2_password.
• Currently, the library doesn't support SSL encryption.
• Doesn't handle split packets (16MB and more).

Binlog event stream replication

Real-time replication client works the following way.

// Start replication from MariaDB GTID
let _options = BinlogOptions::from_mariadb_gtid(GtidList::parse("0-1-270"));

// Start replication from MySQL GTID
let gtid_set =
    "d4c17f0c-4f11-11ea-93e3-325d3e1cd1c8:1-107, f442510a-2881-11ea-b1dd-27916133dbb2:1-7";
let _options = BinlogOptions::from_mysql_gtid(GtidSet::parse(gtid_set));

// Start replication from the position
let _options = BinlogOptions::from_position(String::from("mysql-bin.000008"), 195);

// Start replication from last master position.
// Useful when you are only interested in new changes.
let _options = BinlogOptions::from_end();

// Start replication from first event of first available master binlog.
// Note that binlog files by default have expiration time and deleted.
let options = BinlogOptions::from_start();

let options = ReplicaOptions {
    username: String::from("root"),
    password: String::from("Qwertyu1"),
    blocking: true,
    ssl_mode: SslMode::Disabled,
    binlog: options,
    ..Default::default()
};

let client = BinlogClient::new(options);

for (header, binlog_event) in client.replicate() {
    println!("{:#?}", header);
    println!("{:#?}", binlog_event);
}

A typical transaction has the following structure.

1. GtidEvent if gtid mode is enabled.
2. One or many TableMapEvent events.
   • One or many WriteRowsEvent events.
   • One or many UpdateRowsEvent events.
   • One or many DeleteRowsEvent events.
3. XidEvent indicating commit of the transaction.

It's best practice to use GTID replication with the from_gtid method. Using the approach you can correctly perform replication failover. Note that in GTID mode from_gtid has the following behavior:

• from_gtid(@@gtid_purged) acts like from_start()
• from_gtid(@@gtid_executed) acts like from_end()

Reading binlog files offline

In some cases you will need to read binlog files offline from the file system. This can be done using BinlogReader class.

let file = File::open("mysql-bin.000001").unwrap();
let reader = BinlogReader::new(file).unwrap();

for (header, binlog_event) in reader.read_events() {
    println!("{:#?}", header);
    println!("{:#?}", binlog_event);
}