Canal source connector

note

You can download all the Pulsar connectors on download page.

The Canal source connector pulls messages from MySQL to Pulsar topics.

Configuration

The configuration of the Canal source connector has the following properties.

Property

Name	Required	Default	Description
`username`	true	None	Canal server account (not MySQL).
`password`	true	None	Canal server password (not MySQL).
`destination`	true	None	Source destination that Canal source connector connects to.
`singleHostname`	false	None	Canal server address.
`singlePort`	false	None	Canal server port.
`cluster`	true	false	Whether to enable cluster mode based on Canal server configuration or not. true: cluster mode. If set to true, it talks to `zkServers` to figure out the actual database host. false: standalone mode. If set to false, it connects to the database specified by `singleHostname` and `singlePort`.
`zkServers`	true	None	Address and port of the Zookeeper that Canal source connector talks to figure out the actual database host.
`batchSize`	false	1000	Batch size to fetch from Canal.

Example

Before using the Canal connector, you can create a configuration file through one of the following methods.

JSON

{
    "zkServers": "127.0.0.1:2181",
    "batchSize": "5120",
    "destination": "example",
    "username": "",
    "password": "",
    "cluster": false,
    "singleHostname": "127.0.0.1",
    "singlePort": "11111",
}

YAML

You can create a YAML file and copy the contents below to your YAML file.

configs:
    zkServers: "127.0.0.1:2181"
    batchSize: 5120
    destination: "example"
    username: ""
    password: ""
    cluster: false
    singleHostname: "127.0.0.1"
    singlePort: 11111

Usage

Here is an example of storing MySQL data using the configuration file as above.

Start a MySQL server.

docker pull mysql:5.7
docker run -d -it --rm --name pulsar-mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=canal -e MYSQL_USER=mysqluser -e MYSQL_PASSWORD=mysqlpw mysql:5.7

Create a configuration file mysqld.cnf.

[mysqld]
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
datadir     = /var/lib/mysql
#log-error  = /var/log/mysql/error.log
# By default we only accept connections from localhost
#bind-address   = 127.0.0.1
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-bin=mysql-bin
binlog-format=ROW
server_id=1

Copy the configuration file mysqld.cnf to MySQL server.

docker cp mysqld.cnf pulsar-mysql:/etc/mysql/mysql.conf.d/

Restart the MySQL server.
```
docker restart pulsar-mysql
```

Create a test database in MySQL server.

docker exec -it pulsar-mysql /bin/bash
mysql -h 127.0.0.1 -uroot -pcanal -e 'create database test;'

Start a Canal server and connect to MySQL server.

docker pull canal/canal-server:v1.1.2
docker run -d -it --link pulsar-mysql -e canal.auto.scan=false -e canal.destinations=test -e canal.instance.master.address=pulsar-mysql:3306 -e canal.instance.dbUsername=root -e canal.instance.dbPassword=canal -e canal.instance.connectionCharset=UTF-8 -e canal.instance.tsdb.enable=true -e canal.instance.gtidon=false --name=pulsar-canal-server -p 8000:8000 -p 2222:2222 -p 11111:11111 -p 11112:11112 -m 4096m canal/canal-server:v1.1.2

Start Pulsar standalone.

docker pull apachepulsar/pulsar:2.3.0
docker run -d -it --link pulsar-canal-server -p 6650:6650 -p 8080:8080 -v $PWD/data:/pulsar/data --name pulsar-standalone apachepulsar/pulsar:2.3.0 bin/pulsar standalone

Modify the configuration file canal-mysql-source-config.yaml.

configs:
    zkServers: ""
    batchSize: "5120"
    destination: "test"
    username: ""
    password: ""
    cluster: false
    singleHostname: "pulsar-canal-server"
    singlePort: "11111"

Create a consumer file pulsar-client.py.

import pulsar

client = pulsar.Client('pulsar://localhost:6650')
consumer = client.subscribe('my-topic',
                            subscription_name='my-sub')

while True:
    msg = consumer.receive()
    print("Received message: '%s'" % msg.data())
    consumer.acknowledge(msg)

client.close()

Copy the configuration file canal-mysql-source-config.yaml and the consumer file pulsar-client.py to Pulsar server.

docker cp canal-mysql-source-config.yaml pulsar-standalone:/pulsar/conf/
docker cp pulsar-client.py pulsar-standalone:/pulsar/

Download a Canal connector and start it.

docker exec -it pulsar-standalone /bin/bash
wget https://archive.apache.org/dist/pulsar/pulsar-2.3.0/connectors/pulsar-io-canal-2.3.0.nar -P connectors
./bin/pulsar-admin source localrun \
   --archive ./connectors/pulsar-io-canal-2.3.0.nar \
   --classname org.apache.pulsar.io.canal.CanalStringSource \
   --tenant public \
   --namespace default \
   --name canal \
   --destination-topic-name my-topic \
   --source-config-file /pulsar/conf/canal-mysql-source-config.yaml \
   --parallelism 1

Consume data from MySQL.

docker exec -it pulsar-standalone /bin/bash
python pulsar-client.py

Open another window to log in MySQL server.

docker exec -it pulsar-mysql /bin/bash
mysql -h 127.0.0.1 -uroot -pcanal

Create a table, and insert, delete, and update data in MySQL server.

mysql> use test;
mysql> show tables;
mysql> CREATE TABLE IF NOT EXISTS `test_table`(`test_id` INT UNSIGNED AUTO_INCREMENT,`test_title` VARCHAR(100) NOT NULL,
`test_author` VARCHAR(40) NOT NULL,
`test_date` DATE,PRIMARY KEY ( `test_id` ))ENGINE=InnoDB DEFAULT CHARSET=utf8;
mysql> INSERT INTO test_table (test_title, test_author, test_date) VALUES("a", "b", NOW());
mysql> UPDATE test_table SET test_title='c' WHERE test_title='a';
mysql> DELETE FROM test_table WHERE test_title='c';

Configuration​

Property​

Example​

Usage​

Configuration

Property

Example

Usage