Reroute the cluster

POST /_cluster/reroute

Copy endpoint

Manually change the allocation of individual shards in the cluster. For example, a shard can be moved from one node to another explicitly, an allocation can be canceled, and an unassigned shard can be explicitly allocated to a specific node.

It is important to note that after processing any reroute commands Elasticsearch will perform rebalancing as normal (respecting the values of settings such as cluster.routing.rebalance.enable) in order to remain in a balanced state. For example, if the requested allocation includes moving a shard from node1 to node2 then this may cause a shard to be moved from node2 back to node1 to even things out.

The cluster can be set to disable allocations using the cluster.routing.allocation.enable setting. If allocations are disabled then the only allocations that will be performed are explicit ones given using the reroute command, and consequent allocations due to rebalancing.

The cluster will attempt to allocate a shard a maximum of index.allocation.max_retries times in a row (defaults to 5), before giving up and leaving the shard unallocated. This scenario can be caused by structural problems such as having an analyzer which refers to a stopwords file which doesn’t exist on all nodes.

Once the problem has been corrected, allocation can be manually retried by calling the reroute API with the ?retry_failed URI query parameter, which will attempt a single retry round for these shards.

Parameters

query Query Parameters

Name	Type
`dry_run` If true, then the request simulates the operation. It will calculate the result of applying the commands to the current cluster state and return the resulting cluster state after the commands (and rebalancing) have been applied; it will not actually perform the requested changes.	boolean
`explain` If true, then the response contains an explanation of why the commands can or cannot run.	boolean
`metric` deprecated Limits the information returned to the specified metrics.	string[] \| string
`retry_failed` If true, then retries allocation of shards that are blocked due to too many subsequent allocation failures.	boolean
`master_timeout` Period to wait for a connection to the master node. If no response is received before the timeout expires, the request fails and returns an error.	type TypesDuration = string \| "-1" \| "0"
`timeout` Period to wait for a response. If no response is received before the timeout expires, the request fails and returns an error.	type TypesDuration = string \| "-1" \| "0"

Request Body

application/json

{ commands?:

ClusterRerouteCommand

interface ClusterRerouteCommand {
cancel?: ClusterRerouteCommandCancelAction;
move?: ClusterRerouteCommandMoveAction;
allocate_replica?: ClusterRerouteCommandAllocateReplicaAction;
allocate_stale_primary?: ClusterRerouteCommandAllocatePrimaryAction;
allocate_empty_primary?: ClusterRerouteCommandAllocatePrimaryAction;
}

[]; }

Responses

200 application/json

{ acknowledged: boolean;explanations?:

ClusterRerouteRerouteExplanation

interface ClusterRerouteRerouteExplanation {
command: string;
decisions: ClusterRerouteRerouteDecision[];
parameters: ClusterRerouteRerouteParameters;
}

[];state?: {}; }