Package org.opensearch.cluster.routing.allocation.decider
package org.opensearch.cluster.routing.allocation.decider
Foundation Classes to Decide how to allocate and balance shards
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ClassDescription
AllocationDecideris an abstract base class that allows to make dynamic cluster- or index-wide shard allocation decisions on a per-node basis.A compositeAllocationDecidercombining the "decision" of multipleAllocationDeciderimplementations into a single allocation decision.ThisAllocationDecidercontrols shard allocation based onawarenesskey-value pairs defined in the node configuration.ThisAllocationDecidercontrols re-balancing operations based on the cluster wide active shard state.An enum representation for the configured re-balance type.Similar to theClusterRebalanceAllocationDeciderthisAllocationDecidercontrols the number of currently in-progress re-balance (relocation) operations and restricts node allocations if the configured threshold is reached.ThisAllocationDecidercontrols the number of currently in-progress re-balance (relocation) operations and restricts node allocations if the configured threshold is reached.This abstract class defining basicDecisionused during shard allocation process.Simple class representing a list of decisionsSimple class representing a single decisionThis enumeration defines the possible types of decisionsTheDiskThresholdDeciderchecks that the node a shard is potentially being allocated to has enough disk space.This allocation decider allows shard allocations / rebalancing via the cluster wide settingsEnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING/EnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTINGand the per index settingEnableAllocationDecider.INDEX_ROUTING_ALLOCATION_ENABLE_SETTING/EnableAllocationDecider.INDEX_ROUTING_REBALANCE_ENABLE_SETTING.Allocation values or rather their string representation to be used used withEnableAllocationDecider.CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING/EnableAllocationDecider.INDEX_ROUTING_ALLOCATION_ENABLE_SETTINGvia cluster / index settings.Rebalance values or rather their string representation to be used used withEnableAllocationDecider.CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING/EnableAllocationDecider.INDEX_ROUTING_REBALANCE_ENABLE_SETTINGvia cluster / index settings.ThisAllocationDecidercontrol shard allocation by include and exclude filters via dynamic cluster and index routing settings.An allocation decider that prevents shards from being allocated on any node if the shards allocation has been retried N times without success.ThisNodeLoadAwareAllocationDecidercontrols shard over-allocation due to node failures or otherwise on the surviving nodes.An allocation decider that prevents relocation or allocation from nodes that might not be version compatible.Only allow rebalancing when all shards are active within the shard replication group.An allocation strategy that only allows for a replica to be allocated when the primary is active.An allocation decider that ensures we allocate the shards of a target index for resize operations next to the source primariesThisAllocationDeciderprevents shards that have failed to be restored from a snapshot to be allocated.An allocation decider that prevents multiple instances of the same shard to be allocated on the samenode.ThisAllocationDeciderlimits the number of shards per node on a per index or node-wide basis.ThisAllocationDeciderprevents shards that are currently been snapshotted to be moved to other nodes.TargetPoolAllocationDeciderensures that the different shard types are assigned to the nodes with appropriate capabilities.ThrottlingAllocationDecidercontrols the recovery process per node in the cluster.