Cluster Update Settings
editCluster Update Settings
editUse this API to review and change cluster-wide settings.
To review cluster settings:
GET /_cluster/settings
By default, this API call only returns settings that have been explicitly defined, but can also include the default settings.
Updates to settings can be persistent, meaning they apply across restarts, or transient, where they don’t survive a full cluster restart. Here is an example of a persistent update:
PUT /_cluster/settings { "persistent" : { "indices.recovery.max_bytes_per_sec" : "50mb" } }
This update is transient:
PUT /_cluster/settings?flat_settings=true { "transient" : { "indices.recovery.max_bytes_per_sec" : "20mb" } }
The response to an update returns the changed setting, as in this response to the transient example:
{ ... "persistent" : { }, "transient" : { "indices.recovery.max_bytes_per_sec" : "20mb" } }
You can reset persistent or transient settings by assigning a
null
value. If a transient setting is reset, the first one of these values that is defined is applied:
- the persistent setting
- the setting in the configuration file
- the default value.
This example resets a setting:
PUT /_cluster/settings { "transient" : { "indices.recovery.max_bytes_per_sec" : null } }
The response does not include settings that have been reset:
{ ... "persistent" : {}, "transient" : {} }
You can also reset settings using wildcards. For example, to reset
all dynamic indices.recovery
settings:
PUT /_cluster/settings { "transient" : { "indices.recovery.*" : null } }
Order of Precedence
editThe order of precedence for cluster settings is:
- transient cluster settings
- persistent cluster settings
-
settings in the
elasticsearch.yml
configuration file.
It’s best to set all cluster-wide settings with the settings
API and use the
elasticsearch.yml
file only for local configurations. This way you can be sure that
the setting is the same on all nodes. If, on the other hand, you define different
settings on different nodes by accident using the configuration file, it is very
difficult to notice these discrepancies.
You can find the list of settings that you can dynamically update in Modules.