README.md

Spring Data & MongoDB

Migrations

Data changes over time.

Mongo Documents vs Java Objects:

• A change in a Mongo Document will impact serialization / deserialization process
• A change in Mongo Document will impact the queries
• Changes to collections will also impact queries

Implementation options:

• Manual migrations using scripts (to be avoided at all cost)
• Create migration component ourselves
  • Needs
    • Version detection (& automatic upgrade)
    • Simple configuration
    • Logging
  • Pro
    • Complete control
    • Can meet every aspect of our needs
  • Con
    • Requires more time to develop
    • Is not trivial to create
• Use an existing migration framework
  • Pro
    • Saves time
    • Increased focus on the application domain
  • Con
    • The data migration process is not fully under our control
    • Some applications need more features than frameworks offer

Mongobee

Dependency:

<dependency>
  <groupId>com.github.mongobee</groupId>
  <artifactId>mongobee</artifactId>
</dependency>

Configure bean:

@Bean
public Mongobee mongobee() {
    Mongobee runner = new Mongobee(mongoUri);
    runner.setEnabled(true);
    runner.setChangeLogsScanPackage("yourdomain.*");
    runner.setMongoTemplate(this.mongoTemplate);
    return runner;
}

Changelog:

@ChangeLog(order = "001")
public class DBChangeLog001 {
    @ChangeSet(order = "001", id = "seedCrew", author = "Steven")
    public void seedCrewMembers(MongoTemplate mongoTemplate) {
        // ...
    }
}

We can go here for more information and examples.

Other Options

• Liquibase MongoDB Extension
  • Example project
• Mongock
  • Example project