CqlMigrator

This utility can be used to:

access the CQL scripts that create and modify Cassandra objects (e.g., column families, etc.) for some "scope".
parse developer-supplied metadata from comments in these CQL scripts (each of which implements a single Transition from one "state" to another) to determine the sequence of scripts (or "path") that must be executed to migrate the scope to a given target state from its current state.
execute the CQL scripts in a given path, sequentially.
maintain a persistent copy of the scope's current state for use in subsequent future migrations.

NOTE: The optional 'alternateCurrentStateKeySpace' may be given to specify where the scope's current state tracking data should be stored. It defaults to None, in which case this data is stored in the Session's keyspace. A common case would be accept the default and to ensure that none of the CQL migration scripts attempt to change the Session's keyspace (e.g., via a 'USE' statement). In that case the scope's current state data will be stored in the same keyspace all of its other data. However, you may optionally provide an explicit 'alternateCurrentStateKeySpace' if for some reason you do not want the current state stored in the Session's keyspace (e.g., if some of the CQL scripts do change the Session's keyspace via 'USE' statements).

Author:

Eric Evans

Linear Supertypes

LazyLogging, MigrationGraph[ResourceTransition], AnyRef, Any

Instance Constructors

new CqlMigrator(session: Session, scope: String, originState: String, transitionFinder: ResourceTransitionFinder, alternateCurrentStateKeySpace: Option[String] = None)

session
Cassandra session to use for executing CQL scripts and maintaining current state.
scope
scope of Cassandra objects manipulated by the CQL scripts.
originState
state that this scope is in before the first CQL script is executed (i.e., before any of them are created).
transitionFinder
ResourceTransitionFinder instance that can find resources that implement Transitions, and open each one as an InputStream.
alternateCurrentStateKeySpace
if defined, store the current state tracking data in this keyspace, creating it if it does not exist; defaults to None, in which case the current state tracking data is stored in the Session's keyspace.

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
AnyRef → Any
final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
val alternateCurrentStateKeySpace: Option[String]

if defined, store the current state tracking data in this keyspace, creating it if it does not exist; defaults to None, in which case the current state tracking data is stored in the Session's keyspace.
final def asInstanceOf[T0]: T0

Definition Classes
Any
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
val currentStateKeySpace: String
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def execute(path: Seq[ResourceTransition]): Unit

Execute the given sequence of transitions in order, if the first transition starts with the current state of the scope.
Execute the given sequence of transitions in order, if the first transition starts with the current state of the scope.

Exceptions thrown
IllegalArgumentException if the first transition does not start with the current state of the scope
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def getCurrentState: String

Get the current state of this scope.
def getNonDestructivePath(startState: String, endState: String): Option[Seq[ResourceTransition]]

Definition Classes
MigrationGraph
def getNonDestructivePathFromCurrentState(endState: String): Option[Seq[ResourceTransition]]

Return a non-destructive sequence of transitions (if any exists) that would migrate the scope from its current state to the given end state.
def getPath(startState: String, endState: String): Option[Seq[ResourceTransition]]

Definition Classes
MigrationGraph
def getPathFromCurrentState(endState: String): Option[Seq[ResourceTransition]]

Return a sequence of transitions (if any exists) that would migrate the scope from its current state to the given end state.
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
lazy val logger: Logger

Attributes
protected
Definition Classes
LazyLogging
def migrateNonDestructiveTo(endState: String): Unit

If a sequence of non-destructive transitions exists from the current state to the given end state, execute them in order.
If a sequence of non-destructive transitions exists from the current state to the given end state, execute them in order.

Exceptions thrown
IllegalArgumentException if no sequence of non-destructive transitions exists from the current state to the requested end state
def migrateTo(endState: String): Unit

If a sequence of transitions exists from the current state to the given end state, execute them in order.
If a sequence of transitions exists from the current state to the given end state, execute them in order.

Exceptions thrown
IllegalArgumentException if no sequence of transitions exists from the current state to the requested end state
final def ne(arg0: AnyRef): Boolean

Definition Classes
AnyRef
final def notify(): Unit

Definition Classes
AnyRef
final def notifyAll(): Unit

Definition Classes
AnyRef
val originState: String

state that this scope is in before the first CQL script is executed (i.e., before any of them are created).
val scope: String

scope of Cassandra objects manipulated by the CQL scripts.
val session: Session

Cassandra session to use for executing CQL scripts and maintaining current state.
def setCurrentState(state: String): ResultSet

Set the current state of this scope.
final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
AnyRef
def toString(): String

Definition Classes
AnyRef → Any
val transitionFinder: ResourceTransitionFinder

ResourceTransitionFinder instance that can find resources that implement Transitions, and open each one as an InputStream.
lazy val transitions: Set[ResourceTransition]

Definition Classes
CqlMigrator → MigrationGraph
final def wait(): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Related Docs: object CqlMigrator | package cassandra

class CqlMigrator extends MigrationGraph[ResourceTransition] with LazyLogging

Author:

Instance Constructors

new CqlMigrator(session: Session, scope: String, originState: String, transitionFinder: ResourceTransitionFinder, alternateCurrentStateKeySpace: Option[String] = None)

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

val alternateCurrentStateKeySpace: Option[String]

final def asInstanceOf[T0]: T0

def clone(): AnyRef

val currentStateKeySpace: String

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def execute(path: Seq[ResourceTransition]): Unit

def finalize(): Unit

final def getClass(): Class[_]

def getCurrentState: String

def getNonDestructivePath(startState: String, endState: String): Option[Seq[ResourceTransition]]

def getNonDestructivePathFromCurrentState(endState: String): Option[Seq[ResourceTransition]]

def getPath(startState: String, endState: String): Option[Seq[ResourceTransition]]

def getPathFromCurrentState(endState: String): Option[Seq[ResourceTransition]]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

lazy val logger: Logger

def migrateNonDestructiveTo(endState: String): Unit

def migrateTo(endState: String): Unit

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

val originState: String

val scope: String

val session: Session

def setCurrentState(state: String): ResultSet

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

val transitionFinder: ResourceTransitionFinder

lazy val transitions: Set[ResourceTransition]

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from LazyLogging

Inherited from MigrationGraph[ResourceTransition]

Inherited from AnyRef

Inherited from Any

Ungrouped