Package uk.sky.cqlmigrate

Interface CqlMigrator

public interface CqlMigrator

Interface for managing application schema changes in a synchronized fashion. The implementation classes are expected to implement some locking mechanism so that there are no concurrent schema modifications when multiple threads attempt to make the schema changes on the same cassandra keyspace.

Method Summary

Modifier and Type	Method	Description
void	clean(com.datastax.driver.core.Session session, java.lang.String keyspace)	Drops keyspace if it exists
void	clean(java.lang.String[] hosts, int port, java.lang.String username, java.lang.String password, java.lang.String keyspace)	Drops keyspace if it exists
void	migrate(com.datastax.driver.core.Session session, java.lang.String keyspace, java.util.Collection<java.nio.file.Path> directories)	If all nodes are up and a lock can be acquired this runs migration starting with bootstrap.cql and then the rest in alphabetical order.
void	migrate(java.lang.String[] hosts, int port, java.lang.String username, java.lang.String password, java.lang.String keyspace, java.util.Collection<java.nio.file.Path> directories)	If all nodes are up and a lock can be acquired this runs migration starting with bootstrap.cql and then the rest in alphabetical order.

Method Detail

migrate

void migrate(java.lang.String[] hosts,
             int port,
             java.lang.String username,
             java.lang.String password,
             java.lang.String keyspace,
             java.util.Collection<java.nio.file.Path> directories)

If all nodes are up and a lock can be acquired this runs migration starting with bootstrap.cql and then the rest in alphabetical order. If the migration fails for any reason, the lock will not be released and manual intervention is required to cleanup and fix the issue.

Parameters:

hosts - Comma separated list of cassandra hosts

port - Native transport port for the above cassandra nodes

username - Username for Cassandra's internal authentication using PasswordAuthenticator (if using AllowAllAuthenticator, can be set to any value)

password - Password for Cassandra's internal authentication using PasswordAuthenticator (if using AllowAllAuthenticator, can be set to any value)

keyspace - Keyspace name for which the schema migration needs to be applied

directories - Comma separated list of directory paths containing the cql statements for the schema change

Throws:

ClusterUnhealthyException - if any nodes are down or the schema is not in agreement before running migration

CannotAcquireLockException - if any of the queries to acquire lock fail or CassandraLockConfig.CassandraLockConfigBuilder.withTimeout(Duration) is reached before lock can be acquired.

CannotReleaseLockException - if any of the queries to release lock fail

java.lang.IllegalArgumentException - if any file types other than .cql are found

java.lang.IllegalStateException - if cql file has changed after migration has been run

com.datastax.driver.core.exceptions.DriverException - if any of the migration queries fails

migrate

void migrate(com.datastax.driver.core.Session session,
             java.lang.String keyspace,
             java.util.Collection<java.nio.file.Path> directories)

If all nodes are up and a lock can be acquired this runs migration starting with bootstrap.cql and then the rest in alphabetical order. If the migration fails for any reason, the lock will not be released and manual intervention is required to cleanup and fix the issue.

Parameters:

session - Session to a cassandra cluster

keyspace - Keyspace name for which the schema migration needs to be applied

directories - Comma separated list of directory paths containing the cql statements for the schema change

Throws:

ClusterUnhealthyException - if any nodes are down or the schema is not in agreement before running migration

CannotAcquireLockException - if any of the queries to acquire lock fail or CassandraLockConfig.CassandraLockConfigBuilder.withTimeout(Duration) is reached before lock can be acquired.

CannotReleaseLockException - if any of the queries to release lock fail

java.lang.IllegalArgumentException - if any file types other than .cql are found

java.lang.IllegalStateException - if cql file has changed after migration has been run

com.datastax.driver.core.exceptions.DriverException - if any of the migration queries fails

clean

void clean(java.lang.String[] hosts,
           int port,
           java.lang.String username,
           java.lang.String password,
           java.lang.String keyspace)

Drops keyspace if it exists

Parameters:

hosts - Comma separated list of cassandra hosts

port - Native transport port for the above cassandra nodes

username - Username for Cassandra's internal authentication using PasswordAuthenticator (if using AllowAllAuthenticator, can be set to any value)

password - Password for Cassandra's internal authentication using PasswordAuthenticator (if using AllowAllAuthenticator, can be set to any value)

keyspace - Keyspace name for which the schema migration needs to be applied

Throws:

com.datastax.driver.core.exceptions.DriverException - if query fails

clean

void clean(com.datastax.driver.core.Session session,
           java.lang.String keyspace)

Drops keyspace if it exists

Parameters:

session - Session to a cassandra cluster

keyspace - Keyspace name for which the schema migration needs to be applied

Throws:

com.datastax.driver.core.exceptions.DriverException - if query fails