[[indexing-buffer]]
=== Indexing Buffer

The indexing buffer is used to store newly indexed documents.  When it fills
up, the documents in the buffer are written to a segment on disk. It is divided
between all shards on the node.

The following settings are _static_ and must be configured on every data node
in the cluster:

`indices.memory.index_buffer_size`::

    Accepts either a percentage or a byte size value. It defaults to `10%`,
    meaning that `10%` of the total heap allocated to a node will be used as the
    indexing buffer size.

`indices.memory.min_index_buffer_size`::

    If the `index_buffer_size` is specified as a percentage, then this
    setting can be used to specify an absolute minimum.  Defaults to `48mb`.

`indices.memory.max_index_buffer_size`::

    If the `index_buffer_size` is specified as a percentage, then this
    setting can be used to specify an absolute maximum.  Defaults to unbounded.

`indices.memory.min_shard_index_buffer_size`::

    Sets a hard lower limit for the memory allocated per shard for its own
    indexing buffer. Defaults to `4mb`.