Installing Debezium on OpenShift
For use with Debezium 1.7 on OpenShift Container Platform
Abstract
Preface
Making open source more inclusive
Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message.
Chapter 1. Debezium Overview
Debezium for Red Hat Integration is a distributed platform that captures database operations, creates data change event records for row-level operations, and streams change event records to Apache Kafka topics. Debezium is built on Apache Kafka and is deployed and integrated with AMQ Streams.
Debezium captures row-level changes to a database table and passes corresponding change events to AMQ Streams. Applications can read these change event streams and access the change events in the order in which they occurred.
Debezium is the upstream community project for Debezium for Red Hat Integration.
Debezium has multiple uses, including:
- Data replication
- Updating caches and search indexes
- Simplifying monolithic applications
- Data integration
- Enabling streaming queries
Debezium provides connectors (based on Kafka Connect) for the following common databases:
- Db2
- MySQL
- MongoDB
- Oracle (Technology Preview)
- PostgreSQL
- SQL Server
Chapter 2. Installing Debezium connectors
Install Debezium connectors through AMQ Streams by extending Kafka Connect with connector plug-ins. Following a deployment of AMQ Streams, you can deploy Debezium as a connector configuration through Kafka Connect.
2.1. Kafka topic creation recommendations
Debezium stores data in multiple Apache Kafka topics. The topics must either be created in advance by an administrator, or you can configure Kafka Connect to configure topics automatically.
The following list describes limitations and recommendations to consider when creating topics:
- Database history topics for MySQL, SQL Server, Db2, and Oracle connectors
- Infinite or very long retention.
- Replication factor of at least three in production environments.
- Single partition.
- Other topics
When you enable Kafka log compaction so that only the last change event for a given record is saved, set the following topic properties in Apache Kafka:
-
min.compaction.lag.ms
To ensure that topic consumers have enough time to receive all events and delete markers, specify values for the preceding properties that are larger than the maximum downtime that you expect for your sink connectors. For example, consider the downtime that might occur when you apply updates to sink connectors.
-
- Replicated in production.
Single partition.
You can relax the single partition rule, but your application must handle out-of-order events for different rows in the database. Events for a single row are still totally ordered. If you use multiple partitions, the default behavior is that Kafka determines the partition by hashing the key. Other partition strategies require the use of single message transformations (SMTs) to set the partition number for each record.
2.2. Debezium deployment on AMQ Streams
To set up connectors for Debezium on Red Hat OpenShift Container Platform, you use AMQ Streams to build a Kafka Connect container image that includes the connector plug-in for each connector that you want to use. After the connector starts, it connects to the configured database and generates change event records for each inserted, updated, and deleted row or document.
Beginning with Debezium 1.7, the preferred method for deploying a Debezium connector is to use AMQ Streams to build a Kafka Connect container image that includes the connector plug-in.
During the deployment process, you create and use the following custom resources (CRs):
-
A
KafkaConnect
CR that defines your Kafka Connect instance and includes information about the connector artifacts needs to include in the image. -
A
KafkaConnector
CR that provides details that include information the connector uses to access the source database. After AMQ Streams starts the Kafka Connect pod, you start the connector by applying theKafkaConnector
CR.
In the build specification for the Kafka Connect image, you can specify the connectors that are available to deploy. For each connector plug-in, you can also specify other components that you want to make available for deployment. For example, you can add Service Registry artifacts, or the Debezium scripting component. When AMQ Streams builds the Kafka Connect image, it downloads the specified artifacts, and incorporates them into the image.
The spec.build.output
parameter in the KafkaConnect
CR specifies where to store the resulting Kafka Connect container image. Container images can be stored in a Docker registry, or in an OpenShift ImageStream. To store images in an ImageStream, you must create the ImageStream before you deploy Kafka Connect. ImageStreams are not created automatically.
If you use a KafkaConnect
resource to create a cluster, afterwards you cannot use the Kafka Connect REST API to create or update connectors. You can still use the REST API to retrieve information.
Additional resources
- Configuring Kafka Connect in Using AMQ Streams on OpenShift.
- Creating a new container image automatically using AMQ Streams in Deploying and Upgrading AMQ Streams on OpenShift.
2.2.1. Deploying Debezium with AMQ Streams
You follow the same steps to deploy each type of Debezium connector. The following section describes how to deploy a Debezium MySQL connector.
With earlier versions of AMQ Streams, to deploy Debezium connectors on OpenShift, you were required to first build a Kafka Connect image for the connector. The current preferred method for deploying connectors on OpenShift is to use a build configuration in AMQ Streams to automatically build a Kafka Connect container image that includes the Debezium connector plug-ins that you want to use.
During the build process, the AMQ Streams Operator transforms input parameters in a KafkaConnect
custom resource, including Debezium connector definitions, into a Kafka Connect container image. The build downloads the necessary artifacts from the Red Hat Maven repository or another configured HTTP server. The newly created container is pushed to the container registry that is specified in .spec.build.output
, and is used to deploy a Kafka Connect pod. After AMQ Streams builds the Kafka Connect image, you create KafkaConnector
custom resources to start the connectors that included in the build.
Prerequisites
- You have access to an OpenShift cluster on which the cluster Operator is installed.
- The AMQ Streams Operator is running.
- An Apache Kafka cluster is deployed as documented in Deploying and Upgrading AMQ Streams on OpenShift.
- Kafka Connect is deployed on AMQ Streams
- You have a Red Hat Integration license.
-
The OpenShift
oc
CLI client is installed or you have access to the OpenShift Container Platform web console. Depending on how you intend to store the Kafka Connect build image, you need registry permissions or you must create an ImageStream resource:
- To store the build image in an image registry, such as Red Hat Quay.io or Docker Hub
- An account and permissions to create and manage images in the registry.
- To store the build image as a native OpenShift ImageStream
- An ImageStream resource is deployed to the cluster. You must explicitly create an ImageStream for the cluster. ImageStreams are not available by default.
Procedure
- Log in to the OpenShift cluster.
Create a new Debezium
KafkaConnect
custom resource (CR) for the connector. For example, create aKafkaConnect
CR that specifies themetadata.annotations
andspec.build
properties, as shown in the following example. Save the file with a name such asdbz-connect.yaml
.Example 2.1. A
dbz-connect.yaml
file that defines aKafkaConnect
custom resource that includes a Debezium connectorapiVersion: kafka.strimzi.io/v1beta2 kind: KafkaConnect metadata: name: debezium-kafka-connect-cluster annotations: strimzi.io/use-connector-resources: "true" 1 spec: version: 3.00 build: 2 output: 3 type: imagestream 4 image: debezium-streams-connect:latest plugins: 5 - name: debezium-connector-mysql artifacts: - type: zip 6 url: https://maven.repository.redhat.com/ga/io/debezium/debezium-connector-mysql/1.7.2.Final-redhat-<build_number>/debezium-connector-mysql-1.7.2.Final-redhat-<build_number>-plugin.zip 7 - type: zip url: https://maven.repository.redhat.com/ga/io/apicurio/apicurio-registry-distro-connect-converter/2.0-redhat-<build-number>/apicurio-registry-distro-connect-converter-2.0-redhat-<build-number>.zip - type: zip url: https://maven.repository.redhat.com/ga/io/debezium/debezium-scripting/1.7.2.Final/debezium-scripting-1.7.2.Final.zip bootstrapServers: debezium-kafka-cluster-kafka-bootstrap:9093
Table 2.1. Descriptions of Kafka Connect configuration settings Item Description 1
Sets the
strimzi.io/use-connector-resources
annotation to"true"
to enable the Cluster Operator to useKafkaConnector
resources to configure connectors in this Kafka Connect cluster.2
The
spec.build
configuration specifies where to store the build image and lists the plug-ins to include in the image, along with the location of the plug-in artifacts.3
The
build.output
specifies the registry in which the newly built image is stored.4
Specifies the name and image name for the image output. Valid values for
output.type
aredocker
to push into a container registry like Docker Hub or Quay, orimagestream
to push the image to an internal OpenShift ImageStream. To use an ImageStream, an ImageStream resource must be deployed to the cluster. For more information about specifying thebuild.output
in the KafkaConnect configuration, see the AMQ Streams Build schema reference documentation.5
The
plugins
configuration lists all of the connectors that you want to include in the Kafka Connect image. For each entry in the list, specify a plug-inname
, and information for about the artifacts that are required to build the connector. Optionally, for each connector plug-in, you can include other components that you want to be available for use with the connector. For example, you can add Service Registry artifacts, or the Debezium scripting component.6
The value of
artifacts.type
specifies the file type of the artifact specified in theartifacts.url
. Valid types arezip
,tgz
, orjar
. Debezium connector archives are provided in.zip
file format. JDBC driver files are in.jar
format. Thetype
value must match the type of the file that is referenced in theurl
field.7
The value of
artifacts.url
specifies the address of an HTTP server, such as a Maven repository, that stores the file for the connector artifact. The OpenShift cluster must have access to the specified server.Apply the
KafkaConnect
build specification to the OpenShift cluster by entering the following command:oc create -f dbz-connect.yaml
Based on the configuration specified in the custom resource, the Streams Operator prepares a Kafka Connect image to deploy.
After the build completes, the Operator pushes the image to the specified registry or ImageStream, and starts the Kafka Connect cluster. The connector artifacts that you listed in the configuration are available in the cluster.Create a
KafkaConnector
resource to define an instance of each connector that you want to deploy.
For example, create the followingKafkaConnector
CR, and save it asmysql-inventory-connector.yaml
Example 2.2. A
mysql-inventory-connector.yaml
file that defines theKafkaConnector
custom resource for a Debezium connectorapiVersion: kafka.strimzi.io/v1beta2 kind: KafkaConnector metadata: labels: strimzi.io/cluster: debezium-kafka-connect-cluster name: inventory-connector-mysql 1 spec: class: io.debezium.connector.mysql.MySqlConnector 2 tasksMax: 1 3 config: 4 database.history.kafka.bootstrap.servers: 'debezium-kafka-cluster-kafka-bootstrap.debezium.svc.cluster.local:9092' database.history.kafka.topic: schema-changes.inventory database.hostname: mysql.debezium-mysql.svc.cluster.local 5 database.port: 3306 6 database.user: debezium 7 database.password: dbz 8 database.dbname: mydatabase 9 database.server.name: inventory_connector_mysql 10 database.include.list: public.inventory 11
Table 2.2. Descriptions of connector configuration settings Item Description 1
The name of the connector to register with the Kafka Connect cluster.
2
The name of the connector class.
3
The number of tasks that can operate concurrently.
4
The connector’s configuration.
5
The address of the host database instance.
6
The port number of the database instance.
7
The name of the user account through which Debezium connects to the database.
8
The password for the database user account.
9
The name of the database to capture changes from.
10
The logical name of the database instance or cluster.
The specified name must be formed only from alphanumeric characters or underscores.
Because the logical name is used as the prefix for any Kafka topics that receive change events from this connector, the name must be unique among the connectors in the cluster.
The namespace is also used in the names of related Kafka Connect schemas, and the namespaces of a corresponding Avro schema if you integrate the connector with the Avro connector.11
The list of tables from which the connector captures change events.
Create the connector resource by running the following command:
oc create -n <namespace> -f <kafkaConnector>.yaml
For example,
oc create -n debezium -f {context}-inventory-connector.yaml
The connector is registered to the Kafka Connect cluster and starts to run against the database that is specified by
spec.config.database.dbname
in theKafkaConnector
CR. After the connector pod is ready, Debezium is running.
You are now ready to verify the Debezium deployment.
2.2.2. Verifying that the Debezium connector is running
If the connector starts correctly without errors, it creates a topic for each table that the connector is configured to capture. Downstream applications can subscribe to these topics to retrieve information events that occur in the source database.
To verify that the connector is running, you perform the following operations from the OpenShift Container Platform web console, or through the OpenShift CLI tool (oc):
- Verify the connector status.
- Verify that the connector generates topics.
- Verify that topics are populated with events for read operations ("op":"r") that the connector generates during the initial snapshot of each table.
Prerequisites
- A Debezium connector is deployed to AMQ Streams on OpenShift.
-
The OpenShift
oc
CLI client is installed. - You have access to the OpenShift Container Platform web console.
Procedure
Check the status of the
KafkaConnector
resource by using one of the following methods:From the OpenShift Container Platform web console:
- Navigate to Home → Search.
-
On the Search page, click Resources to open the Select Resource box, and then type
KafkaConnector
. - From the KafkaConnectors list, click the name of the connector that you want to check, for example inventory-connector-mysql.
- In the Conditions section, verify that the values in the Type and Status columns are set to Ready and True.
From a terminal window:
Enter the following command:
oc describe KafkaConnector <connector-name> -n <project>
For example,
oc describe KafkaConnector inventory-connector-mysql -n debezium
The command returns status information that is similar to the following output:
Example 2.3.
KafkaConnector
resource statusName: inventory-connector-mysql Namespace: debezium Labels: strimzi.io/cluster=debezium-kafka-connect-cluster Annotations: <none> API Version: kafka.strimzi.io/v1beta2 Kind: KafkaConnector ... Status: Conditions: Last Transition Time: 2021-12-08T17:41:34.897153Z Status: True Type: Ready Connector Status: Connector: State: RUNNING worker_id: 10.131.1.124:8083 Name: inventory-connector-mysql Tasks: Id: 0 State: RUNNING worker_id: 10.131.1.124:8083 Type: source Observed Generation: 1 Tasks Max: 1 Topics: inventory_connector_mysql inventory_connector_mysql.inventory.addresses inventory_connector_mysql.inventory.customers inventory_connector_mysql.inventory.geom inventory_connector_mysql.inventory.orders inventory_connector_mysql.inventory.products inventory_connector_mysql.inventory.products_on_hand Events: <none>
Verify that the connector created Kafka topics:
From the OpenShift Container Platform web console.
- Navigate to Home → Search.
-
On the Search page, click Resources to open the Select Resource box, and then type
KafkaTopic
. - From the KafkaTopics list, click the name of the topic that you want to check, for example, inventory-connector-mysql.inventory.orders---ac5e98ac6a5d91e04d8ec0dc9078a1ece439081d.
- In the Conditions section, verify that the values in the Type and Status columns are set to Ready and True.
From a terminal window:
Enter the following command:
oc get kafkatopics
The command returns status information that is similar to the following output:
Example 2.4.
KafkaTopic
resource statusNAME CLUSTER PARTITIONS REPLICATION FACTOR READY connect-cluster-configs debezium-kafka-cluster 1 1 True connect-cluster-offsets debezium-kafka-cluster 25 1 True connect-cluster-status debezium-kafka-cluster 5 1 True consumer-offsets---84e7a678d08f4bd226872e5cdd4eb527fadc1c6a debezium-kafka-cluster 50 1 True inventory-connector-mysql---a96f69b23d6118ff415f772679da623fbbb99421 debezium-kafka-cluster 1 1 True inventory-connector-mysql.inventory.addresses---1b6beaf7b2eb57d177d92be90ca2b210c9a56480 debezium-kafka-cluster 1 1 True inventory-connector-mysql.inventory.customers---9931e04ec92ecc0924f4406af3fdace7545c483b debezium-kafka-cluster 1 1 True inventory-connector-mysql.inventory.geom---9f7e136091f071bf49ca59bf99e86c713ee58dd5 debezium-kafka-cluster 1 1 True inventory-connector-mysql.inventory.orders---ac5e98ac6a5d91e04d8ec0dc9078a1ece439081d debezium-kafka-cluster 1 1 True inventory-connector-mysql.inventory.products---df0746db116844cee2297fab611c21b56f82dcef debezium-kafka-cluster 1 1 True inventory-connector-mysql.inventory.products-on-hand---8649e0f17ffcc9212e266e31a7aeea4585e5c6b5 debezium-kafka-cluster 1 1 True schema-changes.inventory debezium-kafka-cluster 1 1 True strimzi-store-topic---effb8e3e057afce1ecf67c3f5d8e4e3ff177fc55 debezium-kafka-cluster 1 1 True strimzi-topic-operator-kstreams-topic-store-changelog---b75e702040b99be8a9263134de3507fc0cc4017b debezium-kafka-cluster 1 1 True
Check topic content.
- From a terminal window, enter the following command:
oc exec -n <project> -it <kafka-cluster> -- /opt/kafka/bin/kafka-console-consumer.sh \ > --bootstrap-server localhost:9092 \ > --from-beginning \ > --property print.key=true \ > --topic=<topic-name>
For example,
oc exec -n debezium -it debezium-kafka-cluster-kafka-0 -- /opt/kafka/bin/kafka-console-consumer.sh \ > --bootstrap-server localhost:9092 \ > --from-beginning \ > --property print.key=true \ > --topic=inventory_connector_mysql.inventory.products_on_hand
The format for specifying the topic name is the same as the
oc describe
command returns in Step 1, for example,inventory_connector_mysql.inventory.addresses
.For each event in the topic, the command returns information that is similar to the following output:
Example 2.5. Content of a Debezium change event
{"schema":{"type":"struct","fields":[{"type":"int32","optional":false,"field":"product_id"}],"optional":false,"name":"inventory_connector_mysql.inventory.products_on_hand.Key"},"payload":{"product_id":101}} {"schema":{"type":"struct","fields":[{"type":"struct","fields":[{"type":"int32","optional":false,"field":"product_id"},{"type":"int32","optional":false,"field":"quantity"}],"optional":true,"name":"inventory_connector_mysql.inventory.products_on_hand.Value","field":"before"},{"type":"struct","fields":[{"type":"int32","optional":false,"field":"product_id"},{"type":"int32","optional":false,"field":"quantity"}],"optional":true,"name":"inventory_connector_mysql.inventory.products_on_hand.Value","field":"after"},{"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":true,"field":"sequence"},{"type":"string","optional":true,"field":"table"},{"type":"int64","optional":false,"field":"server_id"},{"type":"string","optional":true,"field":"gtid"},{"type":"string","optional":false,"field":"file"},{"type":"int64","optional":false,"field":"pos"},{"type":"int32","optional":false,"field":"row"},{"type":"int64","optional":true,"field":"thread"},{"type":"string","optional":true,"field":"query"}],"optional":false,"name":"io.debezium.connector.mysql.Source","field":"source"},{"type":"string","optional":false,"field":"op"},{"type":"int64","optional":true,"field":"ts_ms"},{"type":"struct","fields":[{"type":"string","optional":false,"field":"id"},{"type":"int64","optional":false,"field":"total_order"},{"type":"int64","optional":false,"field":"data_collection_order"}],"optional":true,"field":"transaction"}],"optional":false,"name":"inventory_connector_mysql.inventory.products_on_hand.Envelope"},"payload":{"before":null,"after":{"product_id":101,"quantity":3},"source":{"version":"1.7.2.Final-redhat-00001","connector":"mysql","name":"inventory_connector_mysql","ts_ms":1638985247805,"snapshot":"true","db":"inventory","sequence":null,"table":"products_on_hand","server_id":0,"gtid":null,"file":"mysql-bin.000003","pos":156,"row":0,"thread":null,"query":null},"op":"r","ts_ms":1638985247805,"transaction":null}}
In the preceding example, the
payload
value shows that the connector snapshot generated a read ("op" ="r"
) event from the tableinventory.products_on_hand
. The"before"
state of theproduct_id
record isnull
, indicating that no previous value exists for the record. The"after"
state shows aquantity
of3
for the item withproduct_id
101
.
You can run Debezium with multiple Kafka Connect service clusters and multiple Kafka clusters. The number of connectors that you can deploy to a Kafka Connect cluster depends on the volume and rate of database events.
Next steps
For more information about deploying specific connectors, see the following topics in the Debezium User Guide:
Appendix A. Using your subscription
Debezium is provided through a software subscription. To manage your subscriptions, access your account at the Red Hat Customer Portal.
Accessing your account
- Go to access.redhat.com.
- If you do not already have an account, create one.
- Log in to your account.
Activating a subscription
- Go to access.redhat.com.
- Navigate to My Subscriptions.
- Navigate to Activate a subscription and enter your 16-digit activation number.
Downloading zip and tar files
To access zip or tar files, use the customer portal to find the relevant files for download. If you are using RPM packages, this step is not required.
- Open a browser and log in to the Red Hat Customer Portal Product Downloads page at access.redhat.com/downloads.
- Scroll down to INTEGRATION AND AUTOMATION.
- Click Red Hat Integration to display the Red Hat Integration downloads page.
- Click the Download link for your component.
Revised on 2022-04-13 10:00:41 UTC