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Debezium source connector

The Debezium source connector pulls messages from MySQL or PostgreSQL and persists the messages to Pulsar topics.

Configuration

The configuration of Debezium source connector has the following properties.

NameRequiredDefaultDescription
task.classtruenullA source task class that implemented in Debezium.
database.hostnametruenullThe address of a database server.
database.porttruenullThe port number of a database server.
database.usertruenullThe name of a database user that has the required privileges.
database.passwordtruenullThe password for a database user that has the required privileges.
database.server.idtruenullThe connector’s identifier that must be unique within a database cluster and similar to the database’s server-id configuration property.
database.server.nametruenullThe logical name of a database server/cluster, which forms a namespace and it is used in all the names of Kafka topics to which the connector writes, the Kafka Connect schema names, and the namespaces of the corresponding Avro schema when the Avro Connector is used.
database.whitelistfalsenullA list of all databases hosted by this server which is monitored by the connector.

This is optional, and there are other properties for listing databases and tables to include or exclude from monitoring.
key.convertertruenullThe converter provided by Kafka Connect to convert record key.
value.convertertruenullThe converter provided by Kafka Connect to convert record value.
database.historytruenullThe name of the database history class.
database.history.pulsar.topictruenullThe name of the database history topic where the connector writes and recovers DDL statements.

Note: this topic is for internal use only and should not be used by consumers.
database.history.pulsar.service.urltruenullPulsar cluster service URL for history topic.
pulsar.service.urltruenullPulsar cluster service URL.
offset.storage.topictruenullRecord the last committed offsets that the connector successfully completes.
json-with-envelopefalsefalsePresent the message only consist of payload.

Converter Options

  1. org.apache.kafka.connect.json.JsonConverter

This config json-with-envelope is valid only for the JsonConverter. It's default value is false, the consumer use the schema Schema.KeyValue(Schema.AUTO_CONSUME(), Schema.AUTO_CONSUME(), KeyValueEncodingType.SEPARATED), and the message only consist of payload.

If the config json-with-envelope value is true, the consumer use the schema Schema.KeyValue(Schema.BYTES, Schema.BYTES, the message consist of schema and payload.

  1. org.apache.pulsar.kafka.shade.io.confluent.connect.avro.AvroConverter

If users select the AvroConverter, then the pulsar consumer should use the schema Schema.KeyValue(Schema.AUTO_CONSUME(), Schema.AUTO_CONSUME(), KeyValueEncodingType.SEPARATED), and the message consist of payload.

MongoDB Configuration

NameRequiredDefaultDescription
mongodb.hoststruenullThe comma-separated list of hostname and port pairs (in the form 'host' or 'host:port') of the MongoDB servers in the replica set. The list contains a single hostname and a port pair. If mongodb.members.auto.discover is set to false, the host and port pair are prefixed with the replica set name (e.g., rs0/localhost:27017).
mongodb.nametruenullA unique name that identifies the connector and/or MongoDB replica set or shared cluster that this connector monitors. Each server should be monitored by at most one Debezium connector, since this server name prefixes all persisted Kafka topics emanating from the MongoDB replica set or cluster.
mongodb.usertruenullName of the database user to be used when connecting to MongoDB. This is required only when MongoDB is configured to use authentication.
mongodb.passwordtruenullPassword to be used when connecting to MongoDB. This is required only when MongoDB is configured to use authentication.
mongodb.task.idtruenullThe taskId of the MongoDB connector that attempts to use a separate task for each replica set.

Example of MySQL

You need to create a configuration file before using the Pulsar Debezium connector.

Configuration

You can use one of the following methods to create a configuration file.

  • JSON


    {
    "database.hostname": "localhost",
    "database.port": "3306",
    "database.user": "debezium",
    "database.password": "dbz",
    "database.server.id": "184054",
    "database.server.name": "dbserver1",
    "database.whitelist": "inventory",
    "database.history": "org.apache.pulsar.io.debezium.PulsarDatabaseHistory",
    "database.history.pulsar.topic": "history-topic",
    "database.history.pulsar.service.url": "pulsar://127.0.0.1:6650",
    "key.converter": "org.apache.kafka.connect.json.JsonConverter",
    "value.converter": "org.apache.kafka.connect.json.JsonConverter",
    "pulsar.service.url": "pulsar://127.0.0.1:6650",
    "offset.storage.topic": "offset-topic"
    }

  • YAML

    You can create a debezium-mysql-source-config.yaml file and copy the contents below to the debezium-mysql-source-config.yaml file.


    tenant: "public"
    namespace: "default"
    name: "debezium-mysql-source"
    topicName: "debezium-mysql-topic"
    archive: "connectors/pulsar-io-debezium-mysql-2.8.0.nar"
    parallelism: 1

    configs:

    ## config for mysql, docker image: debezium/example-mysql:0.8
    database.hostname: "localhost"
    database.port: "3306"
    database.user: "debezium"
    database.password: "dbz"
    database.server.id: "184054"
    database.server.name: "dbserver1"
    database.whitelist: "inventory"
    database.history: "org.apache.pulsar.io.debezium.PulsarDatabaseHistory"
    database.history.pulsar.topic: "history-topic"
    database.history.pulsar.service.url: "pulsar://127.0.0.1:6650"

    ## KEY_CONVERTER_CLASS_CONFIG, VALUE_CONVERTER_CLASS_CONFIG
    key.converter: "org.apache.kafka.connect.json.JsonConverter"
    value.converter: "org.apache.kafka.connect.json.JsonConverter"

    ## PULSAR_SERVICE_URL_CONFIG
    pulsar.service.url: "pulsar://127.0.0.1:6650"

    ## OFFSET_STORAGE_TOPIC_CONFIG
    offset.storage.topic: "offset-topic"

Usage

This example shows how to change the data of a MySQL table using the Pulsar Debezium connector.

  1. Start a MySQL server with a database from which Debezium can capture changes.


    $ docker run -it --rm \
    --name mysql \
    -p 3306:3306 \
    -e MYSQL_ROOT_PASSWORD=debezium \
    -e MYSQL_USER=mysqluser \
    -e MYSQL_PASSWORD=mysqlpw debezium/example-mysql:0.8

  2. Start a Pulsar service locally in standalone mode.


    $ bin/pulsar standalone

  3. Start the Pulsar Debezium connector in local run mode using one of the following methods.

    • Use the JSON configuration file as shown previously.

      Make sure the nar file is available at connectors/pulsar-io-debezium-mysql-2.8.0.nar.


      $ bin/pulsar-admin source localrun \
      --archive connectors/pulsar-io-debezium-mysql-2.8.0.nar \
      --name debezium-mysql-source --destination-topic-name debezium-mysql-topic \
      --tenant public \
      --namespace default \
      --source-config '{"database.hostname": "localhost","database.port": "3306","database.user": "debezium","database.password": "dbz","database.server.id": "184054","database.server.name": "dbserver1","database.whitelist": "inventory","database.history": "org.apache.pulsar.io.debezium.PulsarDatabaseHistory","database.history.pulsar.topic": "history-topic","database.history.pulsar.service.url": "pulsar://127.0.0.1:6650","key.converter": "org.apache.kafka.connect.json.JsonConverter","value.converter": "org.apache.kafka.connect.json.JsonConverter","pulsar.service.url": "pulsar://127.0.0.1:6650","offset.storage.topic": "offset-topic"}'

      note

      Currently, the destination topic (specified by the destination-topic-name option ) is a required configuration but it is not used for the Debezium connector to save data. The Debezium connector saves data in the following 4 types of topics:

      • One topic named with the database server name ( database.server.name) for storing the database metadata messages, such as public/default/database.server.name.
      • One topic (database.history.pulsar.topic) for storing the database history information. The connector writes and recovers DDL statements on this topic.
      • One topic (offset.storage.topic) for storing the offset metadata messages. The connector saves the last successfully-committed offsets on this topic.
      • One per-table topic. The connector writes change events for all operations that occur in a table to a single Pulsar topic that is specific to that table.

      If the automatic topic creation is disabled on your broker, you need to manually create the above 4 types of topics and the destination topic.

    • Use the YAML configuration file as shown previously.


      $ bin/pulsar-admin source localrun \
      --source-config-file debezium-mysql-source-config.yaml

  4. Subscribe the topic sub-products for the table inventory.products.


    $ bin/pulsar-client consume -s "sub-products" public/default/dbserver1.inventory.products -n 0

  5. Start a MySQL client in docker.


    $ docker run -it --rm \
    --name mysqlterm \
    --link mysql \
    --rm mysql:5.7 sh \
    -c 'exec mysql -h"$MYSQL_PORT_3306_TCP_ADDR" -P"$MYSQL_PORT_3306_TCP_PORT" -uroot -p"$MYSQL_ENV_MYSQL_ROOT_PASSWORD"'

  6. A MySQL client pops out.

    Use the following commands to change the data of the table products.


    mysql> use inventory;
    mysql> show tables;
    mysql> SELECT * FROM products;
    mysql> UPDATE products SET name='1111111111' WHERE id=101;
    mysql> UPDATE products SET name='1111111111' WHERE id=107;

    In the terminal window of subscribing topic, you can find the data changes have been kept in the sub-products topic.

Example of PostgreSQL

You need to create a configuration file before using the Pulsar Debezium connector.

Configuration

You can use one of the following methods to create a configuration file.

  • JSON


    {
    "database.hostname": "localhost",
    "database.port": "5432",
    "database.user": "postgres",
    "database.password": "changeme",
    "database.dbname": "postgres",
    "database.server.name": "dbserver1",
    "plugin.name": "pgoutput",
    "schema.whitelist": "public",
    "table.whitelist": "public.users",
    "pulsar.service.url": "pulsar://127.0.0.1:6650"
    }

  • YAML

    You can create a debezium-postgres-source-config.yaml file and copy the contents below to the debezium-postgres-source-config.yaml file.


    tenant: "public"
    namespace: "default"
    name: "debezium-postgres-source"
    topicName: "debezium-postgres-topic"
    archive: "connectors/pulsar-io-debezium-postgres-2.8.0.nar"
    parallelism: 1

    configs:

    ## config for postgres version 10+, official docker image: postgres:<10+>
    database.hostname: "localhost"
    database.port: "5432"
    database.user: "postgres"
    database.password: "changeme"
    database.dbname: "postgres"
    database.server.name: "dbserver1"
    plugin.name: "pgoutput"
    schema.whitelist: "public"
    table.whitelist: "public.users"

    ## PULSAR_SERVICE_URL_CONFIG
    pulsar.service.url: "pulsar://127.0.0.1:6650"

Notice that pgoutput is a standard plugin of Postgres introduced in version 10 - see Postgres architecture docu. You don't need to install anything, just make sure the WAL level is set to logical (see docker command below and Postgres docu).

Usage

This example shows how to change the data of a PostgreSQL table using the Pulsar Debezium connector.

  1. Start a PostgreSQL server with a database from which Debezium can capture changes.


    $ docker run -d -it --rm \
    --name pulsar-postgres \
    -p 5432:5432 \
    -e POSTGRES_PASSWORD=changeme \
    postgres:13.3 -c wal_level=logical

  2. Start a Pulsar service locally in standalone mode.


    $ bin/pulsar standalone

  3. Start the Pulsar Debezium connector in local run mode using one of the following methods.

    • Use the JSON configuration file as shown previously.

      Make sure the nar file is available at connectors/pulsar-io-debezium-postgres-2.8.0.nar.


      $ bin/pulsar-admin source localrun \
      --archive connectors/pulsar-io-debezium-postgres-2.8.0.nar \
      --name debezium-postgres-source \
      --destination-topic-name debezium-postgres-topic \
      --tenant public \
      --namespace default \
      --source-config '{"database.hostname": "localhost","database.port": "5432","database.user": "postgres","database.password": "changeme","database.dbname": "postgres","database.server.name": "dbserver1","schema.whitelist": "public","table.whitelist": "public.users","pulsar.service.url": "pulsar://127.0.0.1:6650"}'

      note

      Currently, the destination topic (specified by the destination-topic-name option ) is a required configuration but it is not used for the Debezium connector to save data. The Debezium connector saves data in the following 4 types of topics:

      • One topic named with the database server name ( database.server.name) for storing the database metadata messages, such as public/default/database.server.name.
      • One topic (database.history.pulsar.topic) for storing the database history information. The connector writes and recovers DDL statements on this topic.
      • One topic (offset.storage.topic) for storing the offset metadata messages. The connector saves the last successfully-committed offsets on this topic.
      • One per-table topic. The connector writes change events for all operations that occur in a table to a single Pulsar topic that is specific to that table.

      If the automatic topic creation is disabled on your broker, you need to manually create the above 4 types of topics and the destination topic.

    • Use the YAML configuration file as shown previously.


      $ bin/pulsar-admin source localrun \
      --source-config-file debezium-postgres-source-config.yaml

  4. Subscribe the topic sub-users for the public.users table.


    $ bin/pulsar-client consume -s "sub-users" public/default/dbserver1.public.users -n 0

  5. Start a PostgreSQL client in docker.


    $ docker exec -it pulsar-postgresql /bin/bash

  6. A PostgreSQL client pops out.

    Use the following commands to create sample data in the table users.


    psql -U postgres -h localhost -p 5432
    Password for user postgres:

    CREATE TABLE users(
    id BIGINT GENERATED ALWAYS AS IDENTITY, PRIMARY KEY(id),
    hash_firstname TEXT NOT NULL,
    hash_lastname TEXT NOT NULL,
    gender VARCHAR(6) NOT NULL CHECK (gender IN ('male', 'female'))
    );

    INSERT INTO users(hash_firstname, hash_lastname, gender)
    SELECT md5(RANDOM()::TEXT), md5(RANDOM()::TEXT), CASE WHEN RANDOM() < 0.5 THEN 'male' ELSE 'female' END FROM generate_series(1, 100);

    postgres=# select * from users;

    id | hash_firstname | hash_lastname | gender
    -------+----------------------------------+----------------------------------+--------
    1 | 02bf7880eb489edc624ba637f5ab42bd | 3e742c2cc4217d8e3382cc251415b2fb | female
    2 | dd07064326bb9119189032316158f064 | 9c0e938f9eddbd5200ba348965afbc61 | male
    3 | 2c5316fdd9d6595c1cceb70eed12e80c | 8a93d7d8f9d76acfaaa625c82a03ea8b | female
    4 | 3dfa3b4f70d8cd2155567210e5043d2b | 32c156bc28f7f03ab5d28e2588a3dc19 | female


    postgres=# UPDATE users SET hash_firstname='maxim' WHERE id=1;
    UPDATE 1

    In the terminal window of subscribing topic, you can receive the following messages.


    ----- got message -----
    {"before":null,"after":{"id":1,"hash_firstname":"maxim","hash_lastname":"292113d30a3ccee0e19733dd7f88b258","gender":"male"},"source:{"version":"1.0.0.Final","connector":"postgresql","name":"foobar","ts_ms":1624045862644,"snapshot":"false","db":"postgres","schema":"public","table":"users","txId":595,"lsn":24419784,"xmin":null},"op":"u","ts_ms":1624045862648}
    ...many more

Example of MongoDB

You need to create a configuration file before using the Pulsar Debezium connector.

Configuration

You can use one of the following methods to create a configuration file.

  • JSON


    {
    "mongodb.hosts": "rs0/mongodb:27017",
    "mongodb.name": "dbserver1",
    "mongodb.user": "debezium",
    "mongodb.password": "dbz",
    "mongodb.task.id": "1",
    "database.whitelist": "inventory",
    "pulsar.service.url": "pulsar://127.0.0.1:6650"
    }

  • YAML

    You can create a debezium-mongodb-source-config.yaml file and copy the contents below to the debezium-mongodb-source-config.yaml file.


    tenant: "public"
    namespace: "default"
    name: "debezium-mongodb-source"
    topicName: "debezium-mongodb-topic"
    archive: "connectors/pulsar-io-debezium-mongodb-2.8.0.nar"
    parallelism: 1

    configs:

    ## config for pg, docker image: debezium/example-mongodb:0.10
    mongodb.hosts: "rs0/mongodb:27017",
    mongodb.name: "dbserver1",
    mongodb.user: "debezium",
    mongodb.password: "dbz",
    mongodb.task.id: "1",
    database.whitelist: "inventory",

    ## PULSAR_SERVICE_URL_CONFIG
    pulsar.service.url: "pulsar://127.0.0.1:6650"

Usage

This example shows how to change the data of a MongoDB table using the Pulsar Debezium connector.

  1. Start a MongoDB server with a database from which Debezium can capture changes.


    $ docker pull debezium/example-mongodb:0.10
    $ docker run -d -it --rm --name pulsar-mongodb -e MONGODB_USER=mongodb -e MONGODB_PASSWORD=mongodb -p 27017:27017 debezium/example-mongodb:0.10

    Use the following commands to initialize the data.


    ./usr/local/bin/init-inventory.sh

    If the local host cannot access the container network, you can update the file /etc/hosts and add a rule 127.0.0.1 6 f114527a95f. f114527a95f is container id, you can try to get by docker ps -a

  1. Start a Pulsar service locally in standalone mode.


    $ bin/pulsar standalone

  2. Start the Pulsar Debezium connector in local run mode using one of the following methods.

    • Use the JSON configuration file as shown previously.

      Make sure the nar file is available at connectors/pulsar-io-mongodb-2.8.0.nar.


      $ bin/pulsar-admin source localrun \
      --archive connectors/pulsar-io-debezium-mongodb-2.8.0.nar \
      --name debezium-mongodb-source \
      --destination-topic-name debezium-mongodb-topic \
      --tenant public \
      --namespace default \
      --source-config '{"mongodb.hosts": "rs0/mongodb:27017","mongodb.name": "dbserver1","mongodb.user": "debezium","mongodb.password": "dbz","mongodb.task.id": "1","database.whitelist": "inventory","pulsar.service.url": "pulsar://127.0.0.1:6650"}'

      note

      Currently, the destination topic (specified by the destination-topic-name option ) is a required configuration but it is not used for the Debezium connector to save data. The Debezium connector saves data in the following 4 types of topics:

      • One topic named with the database server name ( database.server.name) for storing the database metadata messages, such as public/default/database.server.name.
      • One topic (database.history.pulsar.topic) for storing the database history information. The connector writes and recovers DDL statements on this topic.
      • One topic (offset.storage.topic) for storing the offset metadata messages. The connector saves the last successfully-committed offsets on this topic.
      • One per-table topic. The connector writes change events for all operations that occur in a table to a single Pulsar topic that is specific to that table.

      If the automatic topic creation is disabled on your broker, you need to manually create the above 4 types of topics and the destination topic.

    • Use the YAML configuration file as shown previously.


      $ bin/pulsar-admin source localrun \
      --source-config-file debezium-mongodb-source-config.yaml

  3. Subscribe the topic sub-products for the inventory.products table.


    $ bin/pulsar-client consume -s "sub-products" public/default/dbserver1.inventory.products -n 0

  4. Start a MongoDB client in docker.


    $ docker exec -it pulsar-mongodb /bin/bash

  5. A MongoDB client pops out.


    mongo -u debezium -p dbz --authenticationDatabase admin localhost:27017/inventory
    db.products.update({"_id":NumberLong(104)},{$set:{weight:1.25}})

    In the terminal window of subscribing topic, you can receive the following messages.


    ----- got message -----
    {"schema":{"type":"struct","fields":[{"type":"string","optional":false,"field":"id"}],"optional":false,"name":"dbserver1.inventory.products.Key"},"payload":{"id":"104"}}, value = {"schema":{"type":"struct","fields":[{"type":"string","optional":true,"name":"io.debezium.data.Json","version":1,"field":"after"},{"type":"string","optional":true,"name":"io.debezium.data.Json","version":1,"field":"patch"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"version"},{"type":"string","optional":false,"field":"connector"},{"type":"string","optional":false,"field":"name"},{"type":"int64","optional":false,"field":"ts_ms"},{"type":"string","optional":true,"name":"io.debezium.data.Enum","version":1,"parameters":{"allowed":"true,last,false"},"default":"false","field":"snapshot"},{"type":"string","optional":false,"field":"db"},{"type":"string","optional":false,"field":"rs"},{"type":"string","optional":false,"field":"collection"},{"type":"int32","optional":false,"field":"ord"},{"type":"int64","optional":true,"field":"h"}],"optional":false,"name":"io.debezium.connector.mongo.Source","field":"source"},{"type":"string","optional":true,"field":"op"},{"type":"int64","optional":true,"field":"ts_ms"}],"optional":false,"name":"dbserver1.inventory.products.Envelope"},"payload":{"after":"{\"_id\": {\"$numberLong\": \"104\"},\"name\": \"hammer\",\"description\": \"12oz carpenter's hammer\",\"weight\": 1.25,\"quantity\": 4}","patch":null,"source":{"version":"0.10.0.Final","connector":"mongodb","name":"dbserver1","ts_ms":1573541905000,"snapshot":"true","db":"inventory","rs":"rs0","collection":"products","ord":1,"h":4983083486544392763},"op":"r","ts_ms":1573541909761}}.

FAQ

Debezium postgres connector will hang when create snap


#18 prio=5 os_prio=31 tid=0x00007fd83096f800 nid=0xa403 waiting on condition [0x000070000f534000]
java.lang.Thread.State: WAITING (parking)
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000007ab025a58> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at java.util.concurrent.LinkedBlockingDeque.putLast(LinkedBlockingDeque.java:396)
at java.util.concurrent.LinkedBlockingDeque.put(LinkedBlockingDeque.java:649)
at io.debezium.connector.base.ChangeEventQueue.enqueue(ChangeEventQueue.java:132)
at io.debezium.connector.postgresql.PostgresConnectorTask$Lambda$203/385424085.accept(Unknown Source)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.sendCurrentRecord(RecordsSnapshotProducer.java:402)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.readTable(RecordsSnapshotProducer.java:321)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.lambda$takeSnapshot$6(RecordsSnapshotProducer.java:226)
at io.debezium.connector.postgresql.RecordsSnapshotProducer$Lambda$240/1347039967.accept(Unknown Source)
at io.debezium.jdbc.JdbcConnection.queryWithBlockingConsumer(JdbcConnection.java:535)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.takeSnapshot(RecordsSnapshotProducer.java:224)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.lambda$start$0(RecordsSnapshotProducer.java:87)
at io.debezium.connector.postgresql.RecordsSnapshotProducer$Lambda$206/589332928.run(Unknown Source)
at java.util.concurrent.CompletableFuture.uniRun(CompletableFuture.java:705)
at java.util.concurrent.CompletableFuture.uniRunStage(CompletableFuture.java:717)
at java.util.concurrent.CompletableFuture.thenRun(CompletableFuture.java:2010)
at io.debezium.connector.postgresql.RecordsSnapshotProducer.start(RecordsSnapshotProducer.java:87)
at io.debezium.connector.postgresql.PostgresConnectorTask.start(PostgresConnectorTask.java:126)
at io.debezium.connector.common.BaseSourceTask.start(BaseSourceTask.java:47)
at org.apache.pulsar.io.kafka.connect.KafkaConnectSource.open(KafkaConnectSource.java:127)
at org.apache.pulsar.io.debezium.DebeziumSource.open(DebeziumSource.java:100)
at org.apache.pulsar.functions.instance.JavaInstanceRunnable.setupInput(JavaInstanceRunnable.java:690)
at org.apache.pulsar.functions.instance.JavaInstanceRunnable.setupJavaInstance(JavaInstanceRunnable.java:200)
at org.apache.pulsar.functions.instance.JavaInstanceRunnable.run(JavaInstanceRunnable.java:230)
at java.lang.Thread.run(Thread.java:748)

If you encounter the above problems in synchronizing data, please refer to this and add the following configuration to the configuration file:


max.queue.size=