Package io.atomix.raft.impl

Class ReconfigurationHelper

java.lang.Object
io.atomix.raft.impl.ReconfigurationHelper
public final class ReconfigurationHelper extends Object

  • Constructor Details

    • ReconfigurationHelper

      public ReconfigurationHelper(RaftContext raftContext)

  • Method Details

    • join

      public CompletableFuture<Void> join(Collection<MemberId> clusterMembers)

    • leave

      public CompletableFuture<Void> leave()

    • forceConfigure

      public CompletableFuture<Void> forceConfigure(Map<MemberId,RaftMember.Type> newMembersIds)
      Force configuration works as follows. Assume current members are 0,1,3,4, and we want to force remove 2 and 3. 
      
   External                        Raft 0 (follower)                     Raft 1 (follower)             Raft 2/3
      |                                 |                                     |                        (Members to be removed)
      |    forceConfigure([0,1])        |                                     |                                    |
      |-------------------------------->|                                     |                                    |
      |                                 |                                     |                                    |
      |               Configuration={   |                                     |                                    |
      |                newMembers=[0,1],|                                     |                                    |
      |                oldMembers=[]    |                                     |                                    |
      |                force=TRUE       |                                     |                                    |
      |               Commit new config |   ForceConfigureRequest(newMembers) |                                    |
      |                                 |------------------------------------>|                                    |
      |                                 |               OK                    |Commit new Configuration            |
      |         OK                      |invalid input: '<'------------------------------------|                                    |
      |invalid input: '<'--------------------------------|                                     |        Poll/Vote/Append            |
      |                                 |                                     |invalid input: '<'-----------------------------------|
      |                        election |             poll/vote               |----------------------------------->|
      |                        timeout  ------------------------------------->|     Reject because Force==TRUE     |
      |                                 |               OK                    |                                    |
      |                                 |invalid input: '<'------------------------------------|                                    |
      |                    Become leader|                                     |                                    |
      |                                 |                                     |                                    |
      |             Append InitialEntry |                                     |                                    |
      |       Append ConfigurationEntry |                                     |                                    |
      |               Configuration={   |           AppendEntry               |                                    |
      |                newMembers=[0,1] |------------------------------------>|                                    |
      |                force=FALSE      |invalid input: '<'------------------------------------|                                    |
      |               }                 |                                     |                                    |
      |                                 |------------------------------------>|                                    |
      |                                 |invalid input: '<'------------------------------------|                                    |
      |                                 |                                     |                                    |
      |                Commit new config|            AppendEntry              |On commitIndex update               |
      |                                 |------------------------------------>|Commit new config                   |
      |                                 |                                     |                                    |
      |                                 |                                     |      Poll/Vote                     |
      |                                 |                                     |invalid input: '<'-----------------------------------|
      |                                 |                                     |  Reject because log not uptodate   |
      |                                 |                                     |----------------------------------->|
      |                                 |                                     |                                    |

    • anoint

      public CompletableFuture<Void> anoint()
      Attempts to become the leader.