AbstractShardAllocationStrategy
Java API: Java implementations of custom shard allocation and rebalancing logic used by the ShardCoordinator should extend this abstract class and implement the two methods.
Value members
Abstract methods
Invoked when the location of a new shard is to be decided.
Invoked when the location of a new shard is to be decided.
- Value parameters:
- currentShardAllocations
all actor refs to
ShardRegionand their current allocated shards, in the order they were allocated- requester
actor reference to the ShardRegion that requested the location of the shard, can be returned if preference should be given to the node where the shard was first accessed
- shardId
the id of the shard to allocate
- Returns:
a
Futureof the actor ref of the ShardRegion that is to be responsible for the shard, must be one of the references included in thecurrentShardAllocationsparameter
Invoked periodically to decide which shards to rebalance to another location.
Invoked periodically to decide which shards to rebalance to another location.
- Value parameters:
- currentShardAllocations
all actor refs to
ShardRegionand their current allocated shards, in the order they were allocated- rebalanceInProgress
set of shards that are currently being rebalanced, i.e. you should not include these in the returned set
- Returns:
a
Futureof the shards to be migrated, may be empty to skip rebalance in this round
Concrete methods
- Definition Classes