[[cluster-update-settings]]
== Cluster Update Settings

Allows to update cluster wide specific settings. Settings updated can
either be persistent (applied cross restarts) or transient (will not
survive a full cluster restart). Here is an example:

[source,js]
--------------------------------------------------
curl -XPUT localhost:9200/_cluster/settings -d '{
    "persistent" : {
        "discovery.zen.minimum_master_nodes" : 2
    } 
}' 
--------------------------------------------------

Or:

[source,js]
--------------------------------------------------
curl -XPUT localhost:9200/_cluster/settings -d '{
    "transient" : {
        "discovery.zen.minimum_master_nodes" : 2
    } 
}' 
--------------------------------------------------

The cluster responds with the settings updated. So the response for the
last example will be:

[source,js]
--------------------------------------------------
{
    "persistent" : {},
    "transient" : {
        "discovery.zen.minimum_master_nodes" : "2"
    } 
}' 
--------------------------------------------------

Cluster wide settings can be returned using:

[source,js]
--------------------------------------------------
curl -XGET localhost:9200/_cluster/settings
--------------------------------------------------

There is a specific list of settings that can be updated, those include:

[float]
=== Cluster settings

[float]
==== Routing allocation

[float]
===== Awareness

`cluster.routing.allocation.awareness.attributes`::
     See <<modules-cluster>>.

`cluster.routing.allocation.awareness.force.*`::
     See <<modules-cluster>>.

[float]
===== Balanced Shards

`cluster.routing.allocation.balance.shard`::
     Defines the weight factor for shards allocated on a node 
     (float). Defaults to `0.45f`.

`cluster.routing.allocation.balance.index`::
     Defines a factor to the number of shards per index allocated 
      on a specific node (float). Defaults to `0.5f`.

`cluster.routing.allocation.balance.primary`::
      defines a weight factor for the number of primaries of a specific index 
      allocated on a node (float). `0.05f`.

`cluster.routing.allocation.balance.threshold`::
      minimal optimization value of operations that should be performed (non 
      negative float). Defaults to `1.0f`.

[float]
===== Concurrent Rebalance

`cluster.routing.allocation.cluster_concurrent_rebalance`::
       Allow to control how many concurrent rebalancing of shards are 
       allowed cluster wide, and default it to `2` (integer). `-1` for 
       unlimited. See also <<modules-cluster>>.

[float]
===== Disable allocation

`cluster.routing.allocation.disable_allocation`::
     See <<modules-cluster>>.

`cluster.routing.allocation.disable_replica_allocation`::
     See <<modules-cluster>>.

`cluster.routing.allocation.disable_new_allocation`::
     See <<modules-cluster>>.

[float]
===== Throttling allocation

`cluster.routing.allocation.node_initial_primaries_recoveries`::
     See <<modules-cluster>>.

`cluster.routing.allocation.node_concurrent_recoveries`::
     See <<modules-cluster>>.

[float]
===== Filter allocation

`cluster.routing.allocation.include.*`::
     See <<modules-cluster>>.

`cluster.routing.allocation.exclude.*`::
     See <<modules-cluster>>.

`cluster.routing.allocation.require.*` 
     See <<modules-cluster>>.

[float]
==== Metadata

`cluster.blocks.read_only`::
      Have the whole cluster read only (indices do not accept write operations), metadata is not allowed to be modified (create or delete indices).

[float]
==== Discovery

`discovery.zen.minimum_master_nodes`::
     See <<modules-discovery-zen>>

[float]
==== Threadpools

`threadpool.*`::
     See <<modules-threadpool>>

[float]
=== Index settings

[float]
==== Index filter cache

`indices.cache.filter.size`::
     See <<index-modules-cache>>

`indices.cache.filter.expire` (time)::
     See <<index-modules-cache>>

[float]
==== TTL interval

`indices.ttl.interval` (time):: 
    See <<mapping-ttl-field>>

[float]
==== Recovery

`indices.recovery.concurrent_streams`::
     See <<modules-indices>>

`indices.recovery.file_chunk_size`::
     See <<modules-indices>>

`indices.recovery.translog_ops`::
     See <<modules-indices>>

`indices.recovery.translog_size`::
     See <<modules-indices>>

`indices.recovery.compress`::
     See <<modules-indices>>

`indices.recovery.max_bytes_per_sec`::
     See <<modules-indices>>

[float]
==== Store level throttling

`indices.store.throttle.type`::
      See <<index-modules-store>>

`indices.store.throttle.max_bytes_per_sec`::
      See <<index-modules-store>>

[float]
=== Logger

Logger values can also be updated by setting `logger.` prefix. More
settings will be allowed to be updated.