Class ShardCoordinator$

    • Field Detail

      • MODULE$

        public static final ShardCoordinator$ MODULE$
        Static reference to the singleton instance of this Scala object.
    • Constructor Detail

      • ShardCoordinator$

        public ShardCoordinator$()
    • Method Detail

      • leastShardAllocationStrategy

        public ShardCoordinator.ShardAllocationStrategy leastShardAllocationStrategy​(int absoluteLimit,
                                                                                     double relativeLimit)
        Java API: ShardAllocationStrategy that allocates new shards to the ShardRegion (node) with least number of previously allocated shards.

        When a node is added to the cluster the shards on the existing nodes will be rebalanced to the new node. The LeastShardAllocationStrategy picks shards for rebalancing from the ShardRegions with most number of previously allocated shards. They will then be allocated to the ShardRegion with least number of previously allocated shards, i.e. new members in the cluster. The amount of shards to rebalance in each round can be limited to make it progress slower since rebalancing too many shards at the same time could result in additional load on the system. For example, causing many Event Sourced entites to be started at the same time.

        It will not rebalance when there is already an ongoing rebalance in progress.

        Parameters:
        absoluteLimit - the maximum number of shards that will be rebalanced in one rebalance round
        relativeLimit - fraction (< 1.0) of total number of (known) shards that will be rebalanced in one rebalance round
      • rebalanceWorkerProps

        public Props rebalanceWorkerProps​(java.lang.String typeName,
                                          java.lang.String shard,
                                          ActorRef shardRegionFrom,
                                          scala.concurrent.duration.FiniteDuration handOffTimeout,
                                          scala.collection.immutable.Set<ActorRef> regions,
                                          boolean isRebalance)