voldemort.client.protocol.admin
Class AdminClient.RebalancingOperations

java.lang.Object
  voldemort.client.protocol.admin.AdminClient.RebalancingOperations

Enclosing class:

AdminClient

public class AdminClient.RebalancingOperations
extends java.lang.Object

Encapsulates all operations concerning cluster expansion

Constructor Summary

AdminClient.RebalancingOperations()

Method Summary

void	checkEachServerInNormalState(Cluster cluster) Check the execution state of the server by checking the state of MetadataStore.VoldemortState This function checks if the nodes are all in normal state ( MetadataStore.VoldemortState.NORMAL_SERVER).
void	deleteStoreRebalanceState(int donorNodeId, int stealerNodeId, java.lang.String storeName) Delete the rebalancing metadata related to the store on the stealer node
java.util.List<StoreDefinition>	getCurrentStoreDefinitions(Cluster cluster) Given the cluster metadata, retrieves the list of store definitions.
Versioned<Cluster>	getLatestCluster(java.util.List<java.lang.Integer> requiredNodes) Get the latest cluster from all available nodes in the cluster Throws exception if: A) Any node in the required nodes list fails to respond. B) Cluster is in inconsistent state with concurrent versions for cluster metadata on any two nodes.
Versioned<MetadataStore.VoldemortState>	getRemoteServerState(int nodeId) Retrieve the server MetadataStore.VoldemortState from a remote node.
int	rebalanceNode(RebalanceTaskInfo stealInfo) Rebalance a stealer-donor node pair for a set of stores.
void	rebalanceStateChange(Cluster existingCluster, Cluster transitionCluster, java.util.List<StoreDefinition> existingStoreDefs, java.util.List<StoreDefinition> targetStoreDefs, java.util.List<RebalanceTaskInfo> rebalanceTaskPlanList, boolean swapRO, boolean changeClusterMetadata, boolean changeRebalanceState, boolean rollback, boolean failEarly) Used in rebalancing to indicate change in states.
void	validateReadOnlyStores(Cluster cluster, java.util.List<StoreDefinition> storeDefs) Given a list of store definitions, cluster and admin client returns a boolean indicating if all RO stores are in the correct format.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AdminClient.RebalancingOperations

public AdminClient.RebalancingOperations()

Method Detail

rebalanceNode

public int rebalanceNode(RebalanceTaskInfo stealInfo)

Rebalance a stealer-donor node pair for a set of stores. This is run on the stealer node.

Parameters:

stealInfo - Partition steal information

Returns:

The request id of the async operation

deleteStoreRebalanceState

public void deleteStoreRebalanceState(int donorNodeId,
                                      int stealerNodeId,
                                      java.lang.String storeName)

Delete the rebalancing metadata related to the store on the stealer node

Parameters:

donorNodeId - The donor node id

stealerNodeId - The stealer node id

storeName - The name of the store

getRemoteServerState

public Versioned<MetadataStore.VoldemortState> getRemoteServerState(int nodeId)

Retrieve the server MetadataStore.VoldemortState from a remote node.

Parameters:

nodeId - The node from which we want to retrieve the state

Returns:

The server state

rebalanceStateChange

public void rebalanceStateChange(Cluster existingCluster,
                                 Cluster transitionCluster,
                                 java.util.List<StoreDefinition> existingStoreDefs,
                                 java.util.List<StoreDefinition> targetStoreDefs,
                                 java.util.List<RebalanceTaskInfo> rebalanceTaskPlanList,
                                 boolean swapRO,
                                 boolean changeClusterMetadata,
                                 boolean changeRebalanceState,
                                 boolean rollback,
                                 boolean failEarly)

Used in rebalancing to indicate change in states. Groups the partition plans on the basis of stealer nodes and sends them over. The various combinations and their order of execution is given below where:

• 'cluster' means cluster state is updated
• 'rebalance' means rebalance flag is set.
• 'swap' means stores are swapped.

 | swapRO | changeClusterMetadata | changeRebalanceState | Order                        |
 |   f    |         t             |          t           | cluster -> rebalance         |
 |   f    |         f             |          t           | rebalance                    |
 |   t    |         t             |          f           | cluster -> swap              |
 |   t    |         t             |          t           | cluster -> swap -> rebalance |
 

Similarly for rollback, order means the following:

• 'remove from rebalance' means set rebalance flag false
• 'cluster' means cluster is rolled back
• 'swap' means stores are swapped

 | swapRO | changeClusterMetadata | changeRebalanceState | Order                                    |
 |   f    |         t             |          t           | remove from rebalance -> cluster         |
 |   f    |         f             |          t           | remove from rebalance                    |
 |   t    |         t             |          f           | cluster -> swap                          |
 |   t    |         t             |          t           | remove from rebalance -> cluster -> swap |
 

Parameters:

existingCluster - Current cluster

transitionCluster - Transition cluster

existingStoreDefs - current store defs

targetStoreDefs - transition store defs

rebalanceTaskPlanList - The list of rebalance partition info plans

swapRO - Boolean indicating if we need to swap RO stores

changeClusterMetadata - Boolean indicating if we need to change cluster metadata

changeRebalanceState - Boolean indicating if we need to change rebalancing state

rollback - Do we want to do a rollback step in case of failures?

failEarly - Do we want to fail early while doing state change?

getLatestCluster

public Versioned<Cluster> getLatestCluster(java.util.List<java.lang.Integer> requiredNodes)

Get the latest cluster from all available nodes in the cluster
Throws exception if:
A) Any node in the required nodes list fails to respond.
B) Cluster is in inconsistent state with concurrent versions for cluster metadata on any two nodes.

Parameters:

requiredNodes - List of nodes from which we definitely need an answer

Returns:

Returns the latest cluster metadata

checkEachServerInNormalState

public void checkEachServerInNormalState(Cluster cluster)

Check the execution state of the server by checking the state of MetadataStore.VoldemortState
This function checks if the nodes are all in normal state ( MetadataStore.VoldemortState.NORMAL_SERVER).

Parameters:

cluster - Cluster metadata whose nodes we are checking

Throws:

VoldemortRebalancingException - if any node is not in normal state

getCurrentStoreDefinitions

public java.util.List<StoreDefinition> getCurrentStoreDefinitions(Cluster cluster)

Given the cluster metadata, retrieves the list of store definitions.
It also checks if the store definitions are consistent across the cluster

Parameters:

cluster - The cluster metadata

Returns:

List of store definitions

validateReadOnlyStores

public void validateReadOnlyStores(Cluster cluster,
                                   java.util.List<StoreDefinition> storeDefs)

Given a list of store definitions, cluster and admin client returns a boolean indicating if all RO stores are in the correct format.
This function also takes into consideration nodes which are being bootstrapped for the first time, in which case we can safely ignore checking them ( as they will have default to ro0 )

Parameters:

cluster - Cluster metadata

storeDefs - Complete list of store definitions