Shard Allocation Filteringedit

Shard allocation filtering allows you to specify which nodes are allowed to host the shards of a particular index.

The per-index shard allocation filters explained below work in conjunction with the cluster-wide allocation filters explained in Cluster Level Shard Allocation.

It is possible to assign arbitrary metadata attributes to each node at startup. For instance, nodes could be assigned a rack and a size attribute as follows:

bin/elasticsearch -Enode.attr.rack=rack1 -Enode.attr.size=big  

These attribute settings can also be specified in the elasticsearch.yml config file.

These metadata attributes can be used with the index.routing.allocation.* settings to allocate an index to a particular group of nodes. For instance, we can move the index test to either big or medium nodes as follows:

PUT test/_settings
  "index.routing.allocation.include.size": "big,medium"

Alternatively, we can move the index test away from the small nodes with an exclude rule:

PUT test/_settings
  "index.routing.allocation.exclude.size": "small"

Multiple rules can be specified, in which case all conditions must be satisfied. For instance, we could move the index test to big nodes in rack1 with the following:

PUT test/_settings
  "index.routing.allocation.include.size": "big",
  "index.routing.allocation.include.rack": "rack1"

If some conditions cannot be satisfied then shards will not be moved.

The following settings are dynamic, allowing live indices to be moved from one set of nodes to another:

Assign the index to a node whose {attribute} has at least one of the comma-separated values.
Assign the index to a node whose {attribute} has all of the comma-separated values.
Assign the index to a node whose {attribute} has none of the comma-separated values.

These special attributes are also supported:


Match nodes by node name


Match nodes by host IP address (IP associated with hostname)


Match nodes by publish IP address


Match either _host_ip or _publish_ip


Match nodes by hostname

All attribute values can be specified with wildcards, eg:

PUT test/_settings
  "index.routing.allocation.include._ip": "192.168.2.*"