Installing Debezium
There are several ways to install and use Debezium connectors, so we’ve documented a few of the most common ways to do this.
Installing a Debezium Connector
If you’ve already installedZookeeper,Kafka, andKafka Connect, then using one of Debezium’s connectors is easy. Simply download one or more connector plug-in archives (see below), extract their files into your Kafka Connect environment, and add the parent directory of the extracted plug-in(s) to Kafka Connect’s plugin path. If not the case yet, specify the plugin path in your worker configuration (e.g.connect-distributed.properties) using theplugin.pathconfiguration property. As an example, let’s assume you have downloaded the Debezium MySQL connector archive and extracted its contents to/kafka/connect/debezium-connector-mysql. Then you’d specify the following in the worker config:
plugin.path=/kafka/connectRestart your Kafka Connect process to pick up the new JARs.
连接器插件基于“增大化现实”技术e available from Maven:
If immutable containers are your thing, then check outDebezium’s container images(alternative sourceon DockerHub) for Apache Kafka, Kafka Connect and Apache Zookeeper, with the different Debezium connectors already pre-installed and ready to go. Ourtutorialeven walks you through using these images, and this is a great way to learn what Debezium is all about. Of course you also can run Debezium on Kubernetes andOpenShift.
By default, the directory/kafka/connectis used as plugin directory by the Debezium Docker image for Kafka Connect. So any additional connectors you may wish to use should be added to that directory. Alternatively, you can add further directories to the plugin path by specifying theKAFKA_CONNECT_PLUGINS_DIRenvironment variable when starting the container (e.g.-e KAFKA_CONNECT_PLUGINS_DIR=/kafka/connect/,/path/to/further/plugins). When using the Docker image for Kafka Connect provided by Confluent, you can specify theCONNECT_PLUGIN_PATHenvironment variable to achieve the same.
Not that Java 8 or later is required to run the Debezium connectors.
Consuming Snapshot Releases
Debezium executes nightly builds and deployments into the Sonatype snapshot repository. If you want to try latest and fresh or verify a bug fix you are interested in, then use plugins fromoss.sonatype.orgor view themaster branchversion of this document for direct links to each connector’s plugin artifact. The installation procedure is the same as for regular releases.
Using a Debezium Connector
To use a connector to produce change events for a particular source server/cluster, simply create a configuration file for theMySQL Connector,Postgres Connector,MongoDB Connector,SQL Server Connector,Oracle Connector,Db2 Connectoror卡珊德拉Connectorand use the卡夫卡连接其他APIto add that connector configuration to your Kafka Connect cluster. When the connector starts, it will connect to the source and produce events for each inserted, updated, and deleted row or document.
See the DebeziumConnectorsdocumentation for more information.
Configuring Debezium Topics
Debezium uses (either via Kafka Connect or directly) multiple topics for storing data. The topics have to be either created by an administrator or by Kafka itself by enabling auto-creation for topics. There are certain limitations and recommendations which apply to topics:
Database history topic (for the Debezium connectors for MySQL and SQL Server)
Infinite (or very long) retention (no compaction!)
Replication factor at least 3 for production
Single partition
Other topics
Optionally,log compactionenabled (if you wish to only keep thelastchange event for a given record); in this case the
min.compaction.lag.msanddelete.retention.mstopic-level settings in Apache Kafka should be configured, so that consumers have enough time to receive all events and delete markers; specifically, these values should be larger than the maximum downtime you anticipate for the sink connectors, e.g. when updating themReplicated in production
Single partition
You can relax the single partition rule but your application must handle out-of-order events for different rows in database (events for a single row are still totally ordered). If multiple partitions are used, Kafka will determine the partition by hashing the key by default. Other partition strategies require using SMTs to set the partition number for each record.
Using the Debezium Libraries
Although Debezium is intended to be used as turnkey services, all of JARs and other artifacts are available inMaven Central.
We do provide a small library so applications canembed any Kafka Connect connectorand consume data change events read directly from the source system. This provides a light weight system (since Zookeeper, Kafka, and Kafka Connect services are not needed), but as a consequence it is not as fault tolerant or reliable since the application must manage and maintain all state normally kept inside Kafka’s distributed and replicated logs. It’s perfect for use in tests, and with careful consideration it may be useful in some applications.