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Debezium 0.8 Final Is Released

I’m very happy to announce the release of Debezium 0.8.0.Final!

The key features of Debezium 0.8 are the first work-in-progress version of our Oracle connector (based on the XStream API) and a brand-new parser for MySQL DDL statements. Besides that, there are plenty of smaller new features (e.g. propagation of default values to corresponding Connect schemas, optional propagation of source queries in CDC messages and a largely improved SMT for sinking changes from MongoDB into RDBMS) as well as lots of bug fixes (e.g. around temporal and numeric column types, large transactions with Postgres).

Please see the previous announcements (Beta 1, CR 1) to learn about all the changes in more depth. The Final release largely resembles CR1; apart from further improvements to the Oracle connector (DBZ-792) there’s one nice addition to the MySQL connector contributed by Peter Goransson: when doing a snapshot, it will now expose information about the processed rows via JMX (DBZ-789), which is very handy when snapshotting larger tables.

Please take a look at the change log for the complete list of changes in 0.8.0.Final and general upgrade notes.

What’s next?

We’re continuing our work on the Oracle connector. The work on initial snapshotting is well progressing and it should be part of the next release. Other improvements will be support for structural changes to captured tables after the initial snapshot has been made, more extensive source info metadata and more. Please track DBZ-716 for this work; the improvements are planned to be released incrementally in the upcoming versions of Debezium.

We’ve also started to explore ingesting changes via LogMiner. This is more involved in terms of engineering efforts than using XStream, but it comes with the huge advantage of not requiring a separate license (LogMiner comes with the Oracle database itself). It’s not quite clear yet when we can release something on this front, and we’re also actively exploring further alternatives. But we are quite optimistic and hope to have something some time soon.

The other focus of work is a connector for SQL Server (see DBZ-40). Work on this has started as well, and there should be an Alpha1 release of Debezium 0.9 with a first drop of that connector within the next few weeks.

To find out about some more long term ideas, please check out our roadmap and get in touch with us, if you got any ideas or suggestions for future development.

About Debezium

Debezium is an open source distributed platform that turns your existing databases into event streams, so applications can see and respond almost instantly to each committed row-level change in the databases. Debezium is built on top of Kafka and provides Kafka Connect compatible connectors that monitor specific database management systems. Debezium records the history of data changes in Kafka logs, so your application can be stopped and restarted at any time and can easily consume all of the events it missed while it was not running, ensuring that all events are processed correctly and completely. Debezium is open source under the Apache License, Version 2.0.

Get involved

We hope you find Debezium interesting and useful, and want to give it a try. Follow us on Twitter @debezium, chat with us on Gitter, or join our mailing list to talk with the community. All of the code is open source on GitHub, so build the code locally and help us improve ours existing connectors and add even more connectors. If you find problems or have ideas how we can improve Debezium, please let us know or log an issue.


Debezium 0.8.0.CR1 Is Released

A fantastic Independence Day to all the Debezium users in the U.S.! But that’s not the only reason to celebrate: it’s also with great happiness that I’m announcing the release of Debezium 0.8.0.CR1!

Following our new release scheme, the focus for this candidate release of Debezium 0.8 has been to fix bug reported for last week’s Beta release, accompanied by a small number of newly implemented features.

Thanks a lot to everyone testing the new Antlr-based DDL parser for the MySQL connector; based on the issues you reported, we were able to fix a few bugs in it. As announced recently, for 0.8 the legacy parser will remain the default implementation, but you are strongly encouraged to test out the new one (by setting the connector option ddl.parser.mode to antlr) and report any findings you may have. We’ve planned to switch to the new implementation by default in Debezium 0.9.

In terms of new features, the CR1 release brings support for CITEXT columns in the Postgres connector (DBZ-762). All the relational connectors support it now to convey the original name and length of captured columns using schema parameters in the emitted change messages (DBZ-644). This can come in handy to properly size columns in a sink database for types such as VARCHAR.

Thanks a lot to the following community members who contributed to this release: Andreas Bergmeier, Olavi Mustanoja and Orr Ganani.

Please take a look at the change log for the complete list of changes in 0.8.0.CR1 and general upgrade notes.

What’s next?

Barring any unforeseen issues and critical bug reports, we’ll release Debezium 0.8.0.Final next week.

Once that’s out, we’ll continue work on the Oracle connector (e.g. exploring alternatives to using XStream for ingesting changes from the database as well as initial snapshotting), which remains a "tech preview" component as of 0.8.

We’ll also work towards a connector for SQL Server (see DBZ-40), for which the first steps just have been made today by preparing a Docker-based setup with a CDC-enabled SQL Server instance, allowing to implement and test the connector in the following.

To find out about some more long term ideas, please check out our roadmap and get in touch with us, if you got any ideas or suggestions for future development.

About Debezium

Debezium is an open source distributed platform that turns your existing databases into event streams, so applications can see and respond almost instantly to each committed row-level change in the databases. Debezium is built on top of Kafka and provides Kafka Connect compatible connectors that monitor specific database management systems. Debezium records the history of data changes in Kafka logs, so your application can be stopped and restarted at any time and can easily consume all of the events it missed while it was not running, ensuring that all events are processed correctly and completely. Debezium is open source under the Apache License, Version 2.0.

Get involved

We hope you find Debezium interesting and useful, and want to give it a try. Follow us on Twitter @debezium, chat with us on Gitter, or join our mailing list to talk with the community. All of the code is open source on GitHub, so build the code locally and help us improve ours existing connectors and add even more connectors. If you find problems or have ideas how we can improve Debezium, please let us know or log an issue.


Debezium 0.8.0.Beta1 Is Released

It’s with great excitement that I’m announcing the release of Debezium 0.8.0.Beta1!

This release brings many exciting new features as well as bug fixes, e.g. the first drop of our new Oracle connector, a brand new DDL parser for the MySQL connector, support for MySQL default values and the update to Apache Kafka 1.1.

Due to the big number of changes (the release contains exactly 42 issues overall), we decided to alter our versioning schema a little bit: going forward we may do one or more Beta and CR ("candidate release") releases before doing a final one. This will allow us to get feedback from the community early on, while still completing and polishing specific features. Final (stable) releases will be named like 0.8.0.Final etc.

This release would not have been possible without our outstanding community; a huge "thank you" goes out to the following open source enthusiasts who all contributed to the new version: Echo Xu, Ivan Vucina, Listman Gamboa, Omar Al-Safi, Peter Goransson, Roman Kuchar (who did a tremendous job with the new DDL parser implementation!), Sagar Rao, Saulius Valatka, Sairam Polavarapu, Stephen Powis and WenZe Hu.

Thank you all very much for your help!

Now let’s take a closer look at some of the features new in Debezium 0.8.0.Beta1; as always, you can find the complete list of changes of this release in the change log. Plese take a special look at the breaking changes and the upgrade notes.

XStream-based Oracle Connector (Tech Preview)

Support for a Debezium Oracle connector has been one of the most asked for features for a long time (its original issue number is DBZ-20!). So we are very happy that we eventually can release a first work-in-progress version of that connector. At this point this code is still very much evolving, so it should be considered as a first tech preview. This means it’s not feature complete (most notably, there’s no support for initial snapshots yet), the emitted message format may still change etc. So while we don’t recommend using it in production quite yet, you should definitely give it a try and report back about your experiences.

One challenge for the Oracle connector is how to get the actual change events out of the database. Unlike with MySQL and Postgres, there’s unfortunately no free-to-use and easy-to-work-with API which would allow to do the same for Oracle. After some exploration we decided to base this first version of the connector on the Oracle XStream API. While this (kinda) checks the box for "easy-to-work-with", it doesn’t do so for "free-to-use": using this API requires you to have a license for Oracle’s separate GoldenGate product. We’re fully aware of this being not ideal, but we decided to still go this route as a first step, allowing us to get some experiences with Oracle and also get a connector into the hands of those with the required license handy. Going forward, we are going to explore alternative approaches. We already have some ideas and discussions around this, so please stay tuned (the issue to track is DBZ-137).

The Oracle connector is going to evolve within the next 0.8.x releases. To learn more about it, please check its connector documentation page.

Antlr-based MySQL DDL Parser

In order to build up an internal meta-model of the captured database’s structure, the Debezium MySQL connector needs to parse all issued DDL statements (CREATE TABLE etc.). This used to be done with a hand-written DDL parser which worked reasonably well, but over time it also revealed some shortcomings; as the DDL language is quite extensive, we saw repeatedly bug reports caused by some specific DDL constructs not being parseable.

So we decided to go back to the drawing board and came up with a brand new parser design. Thanks to the great work of Roman Kuchar, we now have a completely new DDL parser which is based on the proven and very mature Antlr parser generator (luckily, the Antlr project provides a complete MySQL grammar). So we should see much less issue reports related to DDL parsing going forward.

For the time being, the old parser still is in place and remains to be the default parser for Debezium 0.8.x. You are very encouraged though to test the new implementation by setting the connector option ddl.parser.mode to antlr and report back if you run into any issues doing so. We plan to improve and polish the Antlr parser during the 0.8.x release line (specifically we’re going to measure its performance and optimize as needed) and switch to it by default as of Debezium 0.9. Eventually, the old parser will be removed in a future release after that.

Further MySQL Connector Changes

The MySQL Connector propagates column default values to corresponding Kafka Connect schemas now (DBZ-191). That’s beneficial when using Avro as serialization format and the schema registry with compatibility checking enabled.

By setting the include.query connector option to true, you can add the original query that caused a data change to the corresponding CDC events (DBZ-706). While disabled by default, this feature can be a useful tool for analyzing and interpreting data changes captured with Debezium.

Some other changes in the MySQL connector include configurability of the heartbeat topic name (DBZ-668), fixes around timezone handling for TIMESTAMP (DBZ-578) and DATETIME columns (DBZ-741) and correct handling of NUMERIC column without an explicit scale value (DBZ-727).

Postgres Connector

The Debezium Connector for Postgres has seen quite a number of bugfixes, including the following ones:

  • wal2json can handle transactions now that are bigger than 1Gb (DBZ-638)

  • the transaction ID is consistently handled as long now (DBZ-673)

  • multiple fixes related to temporal column types (DBZ-681, DBZ-696)

  • OIDs are handled correctly as unsigned int now (DBZ-697, DBZ-701)

MongoDB Connector

Also for the MongoDB Connector a number of small feature implementations and bugfixes has been done:

  • Tested against MongoDB 3.6 (DBZ-529)

  • Nested documents can be flattened using a provided SMT now (DBZ-561), which is useful when sinking changes from MongoDB into a relational database

  • The unwrapping SMT can be used together with Avro now (DBZ-650)

  • The unwrapping SMT can handle arrays with mixed element types (DBZ-649)

  • When interrupted during snapshotting before completion, the connector will redo the snapshot after restarting (DBZ-712)

What’s next?

As per the new Beta/CR/Final release scheme, we hope to get some feedback by the community (i.e. you :) on this Beta release. Depending on the number of issues reported, we’ll either release another Beta or go to CR1 with the next version. The 0.8.0.Final version will be released within a few weeks. Note that the Oracle connector will remain a "tech preview" component also in the final version.

After that, we’ve planned to do a few 0.8.x releases with bug fixes mostly, while work on Debezium 0.9 will commence in parallel. For that we’ve planned to work on a connector for SQL Server (see DBZ-40). We’d also like to explore means of creating consistent materializations of joins from multiple tables' CDC streams, based on the ids of originating transactions. Also there’s the idea and a first prototype of exposing Debezium change events as a reactive event stream (DBZ-566), which might be shipped eventually.

Please take a look at the roadmap for some more long term ideas and get in touch with us, if you got thoughts around that.

About Debezium

Debezium is an open source distributed platform that turns your existing databases into event streams, so applications can see and respond almost instantly to each committed row-level change in the databases. Debezium is built on top of Kafka and provides Kafka Connect compatible connectors that monitor specific database management systems. Debezium records the history of data changes in Kafka logs, so your application can be stopped and restarted at any time and can easily consume all of the events it missed while it was not running, ensuring that all events are processed correctly and completely. Debezium is open source under the Apache License, Version 2.0.

Get involved

We hope you find Debezium interesting and useful, and want to give it a try. Follow us on Twitter @debezium, chat with us on Gitter, or join our mailing list to talk with the community. All of the code is open source on GitHub, so build the code locally and help us improve ours existing connectors and add even more connectors. If you find problems or have ideas how we can improve Debezium, please let us know or log an issue.


Debezium 0.7.5 Is Released

It’s my pleasure to announce the release of Debezium 0.7.5!

This is a bugfix release to the 0.7 release line, which we decided to do while working towards Debezium 0.8. Most notably it fixes an unfortunate bug introduced in 0.7.3 (DBZ-663), where the internal database history topic of the Debezium MySQL connector could be partly deleted under some specific conditions. Please see the dedicated blog post on this issue to find out whether this affects you and what you should do to prevent this issue.

Together with this, we released a couple of other fixes and improvements. Thanks to Maciej Brynski, the performance of the logical table routing SMT has been improved significantly (DBZ-655). Another fix contributed by Maciej is for DBZ-646 which lets the MySQL connector handle CREATE TABLE statements for the TokuDB storage engine now.

And we got some more bugfixes by our fantastic community: Long-term community member Peter Goransson fixed an issue about the snapshot JMX metrics of the MySQL connector, which are now also accessible after the snapshot has been completed (DBZ-640). Andrew Tongen spotted and fixed an issue for the Debezium embedded engine (DBZ-665) which caused offsets to be committed more often than needed. And Matthias Wessendorf upgraded the Debezium dependencies and Docker images to Apache Kafka 1.0.1 (DBZ-647).

Thank you all for your help!

Please refer to the change log for the complete list of changes in Debezium 0.7.5.

What’s next?

Please see the previous release announcement for the next planned features. Due to the unplanned 0.7.5 release, though, the schedule of the next one will likely be extended a little bit.

About Debezium

Debezium is an open source distributed platform that turns your existing databases into event streams, so applications can see and respond almost instantly to each committed row-level change in the databases. Debezium is built on top of Kafka and provides Kafka Connect compatible connectors that monitor specific database management systems. Debezium records the history of data changes in Kafka logs, so your application can be stopped and restarted at any time and can easily consume all of the events it missed while it was not running, ensuring that all events are processed correctly and completely. Debezium is open source under the Apache License, Version 2.0.

Get involved

We hope you find Debezium interesting and useful, and want to give it a try. Follow us on Twitter @debezium, chat with us on Gitter, or join our mailing list to talk with the community. All of the code is open source on GitHub, so build the code locally and help us improve ours existing connectors and add even more connectors. If you find problems or have ideas how we can improve Debezium, please let us know or log an issue.


Debezium 0.7.2 Is Released

It’s my pleasure to announce the release of Debezium 0.7.2!

Amongst the new features there’s support for geo-spatial types, a new snapshotting mode for recovering a lost DB history topic for the MySQL connector, and a message transformation for converting MongoDB change events into a structure which can be consumed by many more sink connectors. And of course we fixed a whole lot of bugs, too.

Debezium 0.7.2 is a drop-in replacement for previous 0.7.x versions. When upgrading from versions earlier than 0.7.0, please check out the release notes of all 0.7.x releases to learn about any steps potentially required for upgrading.

A big thank you goes out to our fantastic community members for their hard work on this release: Andrey Pustovetov, Denis Mikhaylov, Peter Goransson, Robert Coup, Sairam Polavarapu and Tom Bentley.

Now let’s take a closer look at some of new features.

MySQL Connector

The biggest change of the MySQL connector is support for geo-spatial column types such as GEOMETRY, POLYGON, MULTIPOINT etc.

There are two new logical field types — io.debezium.data.geometry.Geometry and io.debezium.data.geometry.Geography — for representing geo-spatial columns in change data messages. These types represent geo-spatial data via WKB ("well-known binary") and SRID (coordinate reference system identifier), allowing downstream consumers to interpret the change events using any existing library with support for parsing WKB. A blog post with more details on this will follow soon.

The new snapshotting mode schema_only_recovery comes in handy when for some reason you lost (parts of) the DB history topic used by the MySQL connector. It’s also useful if you’d like to compact that topic by re-creating it. Please refer to the connector documentation for the details of this mode, esp. when it’s safe (and when not) to make use of it.

Another new feature related to managing the size of the DB history topic is the option to control whether to include all DDL events or only those pertaining to tables captured as per the whitelist/blacklist configuration. Again, check out the connector docs to learn more about the specifics of that setting.

Finally, we fixed a few shortcomings of the MySQL DDL parser (DBZ-524, DBZ-530).

PostgreSQL Connector

Similar to the MySQL connector, there’s largely improved support for geo-spatial columns in Postgres now. More specifically, PostGIS column types can be represented in change data events now. Thanks a lot for Robert Coup who contributed this feature!

Also the support for Postgres array columns has been expanded, e.g. we now support to track changes to VARCHAR and DATE array columns. Note that the connector doesn’t yet work with geo-spatial array columns (should you ever have those), but this should be added soon, too.

If you’d like to include just a subset of the rows of a captured table in snapshots, you may like the ability to specify dedicated SELECT statements to do so. For instance this can be used to exclude any logically deleted records — which you can recognize based on some flag in that table — from the snapshot.

A few bugs in this connector where reported and fixed by community members, too, e.g. the connector can be correctly paused now (thanks, Andrey Pustovetov), and we fixed an issue which could potentially have committed an incorrect offset to Kafka Connect (thanks, Thon Mekathikom).

MongoDB Connector

If you’ve ever compared the structures of change events emitted by the Debezium RDBMS connectors (MySQL, Postgres) and the MongoDB connector, you’ll know that the message structure of the latter is a bit different than the others. Due to the schemaless nature of MongoDB, the change events essentially contain a String with a JSON representation of the applied insert or patch. This structure cannot be consumed by existing sink connectors, such as the Confluent connectors for JDBC or Elasticsearch.

This gets possible now by means of a newly added single message transformation (SMT), which parses these JSON strings and creates a structured Kafka Connect record from it (thanks, Sairam Polavarapu!). When applying this SMT to the JDBC sink connector, you can now stream data changes from MongoDB to any supported relational database.

Note that this SMT is work-in-progress, details of its emitted message structure may still change. Also there are some inherent limitations to what can be achieved with it, if you e.g. have arrays in your MongoDB documents, the record created by this SMT will be structured accordingly, but many sink connectors cannot process such structure.

We have some ideas for further development here, e.g. there could be an option for flattening out (non-array) nested structures, so that e.g. { "address" { "street" : "..." } } would be represented as address_street, which then could be consumed by sink connectors expecting a flat structure.

The new SMT is described in detail in our docs.

What’s next?

Please see the full change log for more details and the complete list of issues fixed in Debezium 0.7.2.

The 0.7.3 release is scheduled for February 14th.

We’ll focus on some more bug fixes, also we’re working on having Debezium regulary emit heartbeat messages to a dedicated topic. This will be practical for diagnostic purposes but also help to regularly trigger commits of the offset in Kafka Connect. That’s beneficial in certain situations when capturing tables which only very infrequently change.

We’ve also worked out a roadmap describing our ideas for future work on Debezium, going beyond the next bugfix releases. While nothing is cast in stone, this is our idea of the features to add in the coming months. If you miss anything important on this roadmap, please tell us either in the comments below or send a message to our Google group. Looking forward to your feedback!

About Debezium

Debezium is an open source distributed platform that turns your existing databases into event streams, so applications can see and respond almost instantly to each committed row-level change in the databases. Debezium is built on top of Kafka and provides Kafka Connect compatible connectors that monitor specific database management systems. Debezium records the history of data changes in Kafka logs, so your application can be stopped and restarted at any time and can easily consume all of the events it missed while it was not running, ensuring that all events are processed correctly and completely. Debezium is open source under the Apache License, Version 2.0.

Get involved

We hope you find Debezium interesting and useful, and want to give it a try. Follow us on Twitter @debezium, chat with us on Gitter, or join our mailing list to talk with the community. All of the code is open source on GitHub, so build the code locally and help us improve ours existing connectors and add even more connectors. If you find problems or have ideas how we can improve Debezium, please let us know or log an issue.


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