Tuesday, November 17, 2009

Tungsten Replicator and Drizzle howto

Last week I got a few hours to spend on making an extractor for Tungsten Replicator which works against the Drizzle transaction log. This post aims to explain how you use it to replicate changes between drizzle instances.

To get a better understanding of the drizzle replication system, please go read the article on Jay Pipes blog, here.

Get the code
First, you need to check the code out from the tungsten sourceforge repo, like this:
svn co https://tungsten.svn.sourceforge.net/svnroot/tungsten/trunk

Then you need to download my patch, here. Unzip it in the trunk/replicator directory and apply it like this:
patch -p0 < drizzle_support.patch

This patch includes all dependencies and the applier I wrote about in the last post.

Build it
Now you need to build tungsten, change working dir to the replicator directory and write
ant

If you got test errors, you can run ant allExceptJunit to skip the tests (there are some environment configurations needed to get the test suite running).

The artifacts end up in the build/ directory.

Get and build Drizzle
Follow the instructions on the drizzle wiki, http://drizzle.org/wiki/Compiling, just make sure that you pass --with-transaction-log-plugin when you ./configure drizzle.

Start Drizzle
Follow the instructions on the drizzle wiki: http://drizzle.org/wiki/Starting_drizzled and add the parameters --transaction-log-enable --default-replicator-enable when starting drizzled, otherwise you wont get a transaction log.

Set up Tungsten Replicator
Using the binaries built before, read the instructions for MySQL on the Continuent page: http://www.continuent.com/community/tungsten-replicator/documentation

Then we need to do some changes to the configuration files, for the master (extractor), use this configuration file as a template. Note that you must change the path to the transaction log. On the slave (applier), use this config file

Now you should be good to go, start your drizzle and tungsten instances and watch the changes replicate.

Note that almost all the involved components (drizzle, drizzle-jdbc, the drizzle extractor and applier) are not recommended for production use yet.

As always, if you have any questions, shoot me an email (krummas@gmail.com) or ping me on #drizzle @ freenode

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