Overview
Summary | Uses |
Current Version | 1.1.0 |
Author | Andreas Dangel (adangel [at] users.sf.net) |
Issue Tracking | |
Source Repository | |
Maven Coordinates | com.github.adangel.liquibase.ext:liquibase-percona |
Supported Database | MySQL |
News
October 19, 2014 | 1.0.0 | compatible with liquibase 3.2.x |
November 6, 2014 | 1.1.0 | compatible with liquibase 3.3.0 |
Readme
Supported Databases
MySQL is the only supported database. The extension checks whether it is being run against a MySQL database. If not, it falls back to the default AddColumn/DropColumn change of liquibase-core.
Liquibase version(s) tested against
- Liquibase 3.2.0 (liquibase-percona 1.0.0)
- Liquibase 3.3.0 (liquibase-percona 1.1.0)
Example
This changeset
<changeSet id="2" author="Alice"> <addColumn tableName="person"> <column name="address" type="varchar(255)"/> </addColumn> </changeSet>
will execute the following command:
pt-online-schema-change --alter="ADD COLUMN address VARCHAR(255)" --host=127.0.0.1 --port=3306 --user=root --password=** --execute D=testdb,t=person
Configuration
The extension supports the following java system properties:
liquibase.percona.failIfNoPT
: true/false. Default: false. If set to true, the database upate will fail, if the commandpt-online-schema-change
is not found. This can be used, to enforce, that percona toolkit is used.liquibase.percona.noAlterSqlDryMode
: true/false. Default: false. When running updateSQL or rollbackSQL in order to generate a migration SQL file, the command line, that would be executed, will be added as a comment. In addition, the SQL statements (as produced by liquibase-core) will also be generated and output into the migration file. This allows to simply execute the generated migration SQL to perform an update. However, the Percona toolkit won't be used. If this property is set totrue
, then no such SQL statements will be output into the migration file.
Using / Installing the extension
Command line liquibase
After extracting the zip file of liquibase, place liquibase-percona-1.1.0.jar
file in the sub directory lib
. The shell script liquibase
/ liquibase.bat
will automatically pick this up and the extension is available.
Via maven
Add the following dependency to your project's pom file:
<project>
<dependencies>
<dependency>
<groupId>com.github.adangel.liquibase.ext</groupId>
<artifactId>liquibase-percona</artifactId>
<!-- use 1.0.0 or 1.1.0 -->
<version>1.1.0</version>
<scope>runtime</scope>
</dependency>
</dependencies>
</project>
Notes
The non-locking update is achieved using triggers. First a new temporary table is created, including the added or dropped columns. Then the data is copied in chunks. While to copy is in progress, any newly created or deleted or updated rows are copied, too. This is done by adding triggers to the original table. After the copy is finished, the original table is dropped and the temporary table is renamed.
This means, that pt-online-schema-change cannot be used, if the table already uses triggers.
The command pt-online-schema-change
is searched only on the PATH
.
Building this extension
Simply run mvn clean install
.
In order to execute the integration tests, run mvn clean install -Prun-its
. Please note, that a MySQL server/Percona server is needed. See the properties config_... in pom.xml
for connection details.
Common Problems
NoSuchMethodError: PerconaDropColumnChange.getColumns()Ljava/util/List
The full error message:
Unexpected error running Liquibase: liquibase.exception.UnexpectedLiquibaseException:
java.lang.NoSuchMethodError: liquibase.ext.percona.PerconaDropColumnChange.getColumns()Ljava/util/List;
This means, you are trying to use version 1.1.0 of the extension with liquibase 3.2.x. This is an unsupported combination. For Liquibase 3.2.x, you'll need to use liquibase-percona 1.0.0
References