Apache Flink CDC

Overview

Flink CDC handles real-time and batch data integration, including full database and sharded-table synchronization. Log-based capture, initial snapshots, schema evolution, and data transformation support a range of migration and ongoing replication needs. The project is distributed under the Apache 2.0 License, and its self-hosted deployment is on-premise.

This is infrastructure software, not a managed service: deployment involves downloading Flink CDC and connector JARs and running them with Apache Flink. That gives teams control over their environment, but also makes operating and maintaining that environment part of the choice.

Key features

Three ways to define work

The YAML Pipeline API lets users declare sources, sinks, routing, transformations, and schema evolution rules. It suits repeatable pipeline definitions without requiring every job to be expressed as custom application code. SQL and DataStream APIs provide alternatives for defining CDC sources and building custom Flink streaming applications; those options are more appropriate when a team wants its work shaped around Flink APIs.

Database and sink coverage

Pipeline connectors include Doris, Elasticsearch, Fluss, Hudi, Iceberg, Kafka, MaxCompute, MySQL, OceanBase, Oracle, Paimon, PostgreSQL, and StarRocks. SQL and DataStream source connectors include MySQL, PostgreSQL, Oracle, SQL Server, MongoDB, OceanBase, TiDB, Db2, and Vitess. This makes the project relevant to teams combining several named databases or destinations, though connector coverage should be checked against the exact workflow: the two connector lists serve different roles.

Compatibility and operation

Flink CDC 3.6 is compatible with Flink 1.20 and 2.2. Version 3.6.0 is built on JDK 11 and requires JDK 11 or later, so teams need to account for both the Flink and Java runtime requirements. The repository directs users to a mailing list for questions and Flink JIRA for problems. It links to a security policy.

Pricing

Apache Flink CDC is free: the Apache License 2.0 plan costs 0.00 USD per free and includes released JARs and connectors. There is no paid tier or free trial to weigh against a lower-cost option. The trade-off is operational rather than tier-based: users deploy and run the software themselves with Apache Flink, rather than choosing a hosted plan with a stated seat or usage allowance.

Platforms

Flink CDC supports Linux, macOS, and Windows, and is self-hosted. Its deployment model is on-premise. Platform availability does not remove the requirement to run it with an Apache Flink deployment, so it is a better fit for teams prepared to manage that infrastructure than for buyers seeking a turnkey hosted CDC service.

Who it's for

Choose Flink CDC if your team already works with Apache Flink or is prepared to operate it, and needs database synchronization, schema evolution, or transformations across the listed sources and sinks. The YAML Pipeline API is useful for declarative pipelines, while SQL and DataStream APIs suit custom Flink application work.

Look elsewhere if your priority is avoiding self-hosted infrastructure, or if your required source or destination is outside the connectors named above. The project provides several ways to build pipelines, but deployment still depends on a Flink environment and the stated Java version.

Pros and cons

• Pros: YAML, SQL, and DataStream APIs give teams distinct approaches for declarative pipelines and custom Flink applications.
• Pros: Full and sharded-table synchronization, snapshots, schema evolution, and transformations cover more than basic change capture.
• Pros: The named source and pipeline connector sets span a broad mix of databases and destinations.
• Cons: Self-hosted deployment requires an Apache Flink environment, adding infrastructure responsibility for adopters.
• Cons: Flink CDC 3.6.0 requires JDK 11 or later, which teams must accommodate alongside Flink compatibility.

Alternatives

For another free, open-source CDC option, consider Canal, which supports Linux, macOS, API, and self-hosted use. pgstream is also free and self-hosted on Linux or macOS, and is described as a CDC CLI and Go library.

dbmazz offers a free self-hosted plan with an open-source engine, CLI, terminal dashboard, local web UI, and community support. TiCDC is another free, self-hosted option, with no paid plans or usage caps stated on its pages.

If a freemium service is more suitable, Decodable has a free plan with 24 hours / 10GiB stream retention, 20 streams, four running tasks, and Small and Medium task sizes. Estuary offers free plans as well as a $100.00 USD monthly pay-as-you-go plan. PeerDB has a free open-source plan aimed at individuals, with Docker setup, CDC, streaming query, and query layer features. Striim offers freemium plans, including a Developer plan with 25 million events per month.

Browse more tools in Change Data Capture Software or compare projects in Open Source License Compliance Software.

Verdict

Apache Flink CDC is a strong fit for teams that want open-source CDC pipelines integrated with Apache Flink, particularly when its multiple APIs and broad named connector sets match their data estate. Its main reason to choose is the combination of synchronization, transformation, and schema-evolution capabilities at no software cost. Its main reason to look elsewhere is the need to provision and maintain a Flink environment and meet the runtime requirements.