This is the zookeeper listener that triggers all the state transitions for a replica
o != arg0
is the same as !(o == (arg0))
.
o != arg0
is the same as !(o == (arg0))
.
the object to compare against this object for dis-equality.
false
if the receiver object is equivalent to the argument; true
otherwise.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
o == arg0
is the same as if (o eq null) arg0 eq null else o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
o == arg0
is the same as o.equals(arg0)
.
o == arg0
is the same as o.equals(arg0)
.
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
This method is used to cast the receiver object to be of type T0
.
This method is used to cast the receiver object to be of type T0
.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression1.asInstanceOf[String]
will throw a ClassCastException
at runtime, while the expressionList(1).asInstanceOf[List[String]]
will not. In the latter example, because the type argument is erased as
part of compilation it is not possible to check whether the contents of the list are of the requested typed.
the receiver object.
This method creates and returns a copy of the receiver object.
This method creates and returns a copy of the receiver object.
The default implementation of the clone
method is platform dependent.
a copy of the receiver object.
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
This method is used to test whether the argument (arg0
) is a reference to the
receiver object (this
).
The eq
method implements an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence relation] on
non-null instances of AnyRef
:
* It is reflexive: for any non-null instance x
of type AnyRef
, x.eq(x)
returns true
.
* It is symmetric: for any non-null instances x
and y
of type AnyRef
, x.eq(y)
returns true
if and
only if y.eq(x)
returns true
.
* It is transitive: for any non-null instances x
, y
, and z
of type AnyRef
if x.eq(y)
returns true
and y.eq(z)
returns true
, then x.eq(z)
returns true
.
Additionally, the eq
method has three other properties.
* It is consistent: for any non-null instances x
and y
of type AnyRef
, multiple invocations of
x.eq(y)
consistently returns true
or consistently returns false
.
* For any non-null instance x
of type AnyRef
, x.eq(null)
and null.eq(x)
returns false
.
* null.eq(null)
returns true
.
When overriding the equals
or hashCode
methods, it is important to ensure that their behavior is
consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2
), they
should be equal to each other (o1 == o2
) and they should hash to the same value (o1.hashCode == o2.hashCode
).
the object to compare against this object for reference equality.
true
if the argument is a reference to the receiver object; false
otherwise.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
This method is used to compare the receiver object (this
) with the argument object (arg0
) for equivalence.
The default implementations of this method is an [http://en.wikipedia.org/wiki/Equivalence_relation equivalence
relation]:
* It is reflexive: for any instance x
of type Any
, x.equals(x)
should return true
.
* It is symmetric: for any instances x
and y
of type Any
, x.equals(y)
should return true
if and
only if y.equals(x)
returns true
.
* It is transitive: for any instances x
, y
, and z
of type AnyRef
if x.equals(y)
returns true
and
y.equals(z)
returns true
, then x.equals(z)
should return true
.
If you override this method, you should verify that your implementation remains an equivalence relation.
Additionally, when overriding this method it is often necessary to override hashCode
to ensure that objects
that are "equal" (o1.equals(o2)
returns true
) hash to the same
scala.Int
(o1.hashCode.equals(o2.hashCode)
).
the object to compare against this object for equality.
true
if the receiver object is equivalent to the argument; false
otherwise.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
This method is called by the garbage collector on the receiver object when garbage collection determines that there are no more references to the object.
The details of when and if the finalize
method are invoked, as well as the interaction between finalize
and non-local returns and exceptions, are all platform dependent.
Returns a representation that corresponds to the dynamic class of the receiver object.
Returns a representation that corresponds to the dynamic class of the receiver object.
The nature of the representation is platform dependent.
a representation that corresponds to the dynamic class of the receiver object.
This API exercises the replica's state machine.
This API exercises the replica's state machine. It ensures that every state transition happens from a legal previous state to the target state. Valid state transitions are: NonExistentReplica --> NewReplica --send LeaderAndIsr request with current leader and isr to the new replica and UpdateMetadata request for the partition to every live broker
NewReplica -> OnlineReplica --add the new replica to the assigned replica list if needed
OnlineReplica,OfflineReplica -> OnlineReplica --send LeaderAndIsr request with current leader and isr to the new replica and UpdateMetadata request for the partition to every live broker
NewReplica,OnlineReplica,OfflineReplica,ReplicaDeletionIneligible -> OfflineReplica --send StopReplicaRequest to the replica (w/o deletion) --remove this replica from the isr and send LeaderAndIsr request (with new isr) to the leader replica and UpdateMetadata request for the partition to every live broker.
OfflineReplica -> ReplicaDeletionStarted --send StopReplicaRequest to the replica (with deletion)
ReplicaDeletionStarted -> ReplicaDeletionSuccessful -- mark the state of the replica in the state machine
ReplicaDeletionStarted -> ReplicaDeletionIneligible -- mark the state of the replica in the state machine
ReplicaDeletionSuccessful -> NonExistentReplica -- remove the replica from the in memory partition replica assignment cache
The replica for which the state transition is invoked
The end state that the replica should be moved to
This API is invoked by the broker change controller callbacks and the startup API of the state machine
This API is invoked by the broker change controller callbacks and the startup API of the state machine
The list of replicas (brokers) that need to be transitioned to the target state
The state that the replicas should be moved to The controller's allLeaders cache should have been updated before this
Returns a hash code value for the object.
Returns a hash code value for the object.
The default hashing algorithm is platform dependent.
Note that it is allowed for two objects to have identical hash codes (o1.hashCode.equals(o2.hashCode)
) yet
not be equal (o1.equals(o2)
returns false
). A degenerate implementation could always return 0
.
However, it is required that if two objects are equal (o1.equals(o2)
returns true
) that they have
identical hash codes (o1.hashCode.equals(o2.hashCode)
). Therefore, when overriding this method, be sure
to verify that the behavior is consistent with the equals
method.
the hash code value for the object.
This method is used to test whether the dynamic type of the receiver object is T0
.
This method is used to test whether the dynamic type of the receiver object is T0
.
Note that the test result of the test is modulo Scala's erasure semantics. Therefore the expression1.isInstanceOf[String]
will return false
, while the expression List(1).isInstanceOf[List[String]]
will
return true
. In the latter example, because the type argument is erased as part of compilation it is not
possible to check whether the contents of the list are of the requested typed.
true
if the receiver object is an instance of erasure of type T0
; false
otherwise.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
o.ne(arg0)
is the same as !(o.eq(arg0))
.
the object to compare against this object for reference dis-equality.
false
if the argument is not a reference to the receiver object; true
otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up a single thread that is waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Wakes up all threads that are waiting on the receiver object's monitor.
Invoked on controller shutdown.
Invoked on controller shutdown.
Invoked on successful controller election.
Invoked on successful controller election. First registers a broker change listener since that triggers all state transitions for replicas. Initializes the state of replicas for all partitions by reading from zookeeper. Then triggers the OnlineReplica state change for all replicas.
Returns a string representation of the object.
Returns a string representation of the object.
The default representation is platform dependent.
a string representation of the object.
This class represents the state machine for replicas. It defines the states that a replica can be in, and transitions to move the replica to another legal state. The different states that a replica can be in are - 1. NewReplica : The controller can create new replicas during partition reassignment. In this state, a replica can only get become follower state change request. Valid previous state is NonExistentReplica 2. OnlineReplica : Once a replica is started and part of the assigned replicas for its partition, it is in this state. In this state, it can get either become leader or become follower state change requests. Valid previous state are NewReplica, OnlineReplica or OfflineReplica 3. OfflineReplica : If a replica dies, it moves to this state. This happens when the broker hosting the replica is down. Valid previous state are NewReplica, OnlineReplica 4. ReplicaDeletionStarted: If replica deletion starts, it is moved to this state. Valid previous state is OfflineReplica 5. ReplicaDeletionSuccessful: If replica responds with no error code in response to a delete replica request, it is moved to this state. Valid previous state is ReplicaDeletionStarted 6. ReplicaDeletionIneligible: If replica deletion fails, it is moved to this state. Valid previous state is ReplicaDeletionStarted 7. NonExistentReplica: If a replica is deleted successfully, it is moved to this state. Valid previous state is ReplicaDeletionSuccessful