Confluent Platform 6.2社区版中ksqldb从0.17版本升级至0.19版本的可行方案咨询

Hey there! Let's break down how to safely upgrade your ksqlDB from version 0.17 (bundled with Confluent Platform 6.2 Community Edition) to 0.19. I've put together a practical, step-by-step approach to make this go smoothly:

First, let's cover the critical prep steps to avoid data loss or downtime surprises:

• Backup everything:
  • Copy your ksqlDB config files (usually in <confluent-home>/etc/ksqldb/ — think ksql-server.properties, connect-avro-distributed.properties if you're using embedded connectors) to a safe location.
  • Export all your stream and table definitions: Use the ksqlDB CLI to run LIST STREAMS; and LIST TABLES;, then run DESCRIBE EXTENDED <stream/table-name>; for each to save their full DDL. This lets you rebuild objects if needed.
  • Note the path of your ksqlDB state directory (set via ksql.streams.state.dir in config) — we'll need this to retain existing state data.
• Check compatibility: Confirm your existing Kafka cluster (from Confluent 6.2) works with ksqlDB 0.19. Generally, Confluent ecosystem components are cross-compatible across minor versions, but double-check that none of your existing ksql queries use deprecated syntax that's removed in 0.19.
• Stop the old ksqlDB service: Use confluent stop ksqldb-server if you're using the Confluent CLI, or send a SIGTERM to the ksqlDB process directly. Wait for it to shut down fully before proceeding.

You have two solid options here, depending on whether you want to upgrade just ksqlDB or align with a newer Confluent Platform release:

路径1: 单独升级ksqlDB二进制包 #

This is the lightweight option if you don't want to touch other Confluent components:

• Download the ksqlDB 0.19 Community Edition standalone package matching your OS (Linux/macOS).
• Rename your existing <confluent-home>/ksqldb directory to ksqldb-old (so you can roll back easily).
• Extract the new ksqlDB 0.19 package into <confluent-home>/ and rename the extracted folder to ksqldb.
• Copy your backed-up config files into <confluent-home>/etc/ksqldb/. Then, compare against the new ksql-server.properties.template file to:
  • Add any new required configs (e.g., 0.19 might have updated settings for schema registry integration).
  • Remove or replace deprecated configs (check the release notes for 0.18 and 0.19 to spot these).
  • Ensure ksql.streams.state.dir points to your original state directory (so ksqlDB loads existing stream/table state).

路径2: 升级到Confluent Platform 6.3.x #

ksqlDB 0.19 is bundled with Confluent Platform 6.3.x, so this is a more holistic upgrade if you want all components to be aligned:

• Download Confluent Platform 6.3.x Community Edition.
• Follow the standard Confluent upgrade process:
  • Stop individual components one by one (starting with ksqlDB, then connectors, schema registry, finally Kafka if needed).
  • Replace the component directories (e.g., <confluent-home>/ksqldb, <confluent-home>/schema-registry) with the new versions from 6.3.x.
  • Migrate your config files, updating any settings that changed between 6.2 and 6.3.x.
  • Restart components in reverse order (Kafka first, then schema registry, connectors, ksqlDB).

Once you've deployed the new ksqlDB version:

• Start the service: Use confluent start ksqldb-server or run <confluent-home>/bin/ksql-server-start <confluent-home>/etc/ksqldb/ksql-server.properties.
• Connect via the ksqlDB CLI: Run ksql http://<your-ksqldb-host>:8088.
• Run quick validation checks:
  • SELECT * FROM <your-test-stream> LIMIT 5; to confirm data flows correctly.
  • SHOW STREAMS EXTENDED; and SHOW TABLES EXTENDED; to verify state stores are loaded and healthy.
  • Test any custom queries or UDFs you use to ensure they work as expected.
• Check the ksqlDB logs (in <confluent-home>/logs/ksql-server.log) for any errors or warnings that need addressing.

If something goes wrong, don't panic — we have backups:

• Stop the new ksqlDB service immediately.
• Delete the new ksqldb directory, then rename ksqldb-old back to ksqldb.
• Restore your original config files.
• Start the old ksqlDB 0.17 service. Your streams, tables, and state should be exactly as they were before the upgrade.

内容的提问来源于stack exchange，提问作者ma2 b3