Index blocksedit

Index blocks limit the kind of operations that are available on a certain index. The blocks come in different flavours, allowing to block write, read, or metadata operations. The blocks can be set / removed using dynamic index settings, or can be added using a dedicated API, which also ensures for write blocks that, once successfully returning to the user, all shards of the index are properly accounting for the block, for example that all in-flight writes to an index have been completed after adding the write block.

Index block settingsedit

The following dynamic index settings determine the blocks present on an index:

index.blocks.read_only
Set to true to make the index and index metadata read only, false to allow writes and metadata changes.
index.blocks.read_only_allow_delete

Similar to index.blocks.read_only, but also allows deleting the index to make more resources available. The disk-based shard allocator may add and remove this block automatically.

Deleting documents from an index to release resources - rather than deleting the index itself - can increase the index size over time. When index.blocks.read_only_allow_delete is set to true, deleting documents is not permitted. However, deleting the index itself releases the read-only index block and makes resources available almost immediately.

Elasticsearch adds and removes the read-only index block automatically when the disk utilization falls below the high watermark, controlled by cluster.routing.allocation.disk.watermark.flood_stage.

index.blocks.read
Set to true to disable read operations against the index.
index.blocks.write
Set to true to disable data write operations against the index. Unlike read_only, this setting does not affect metadata. For instance, you can close an index with a write block, but you cannot close an index with a read_only block.
index.blocks.metadata
Set to true to disable index metadata reads and writes.

Add index block APIedit

Adds an index block to an index.

PUT /my-index-000001/_block/write

Requestedit

PUT /<index>/_block/<block>

Path parametersedit

<index>

(Optional, string) Comma-separated list or wildcard expression of index names used to limit the request.

To add blocks to all indices, use _all or *. To disallow the adding of blocks to indices with _all or wildcard expressions, change the action.destructive_requires_name cluster setting to true. You can update this setting in the elasticsearch.yml file or using the cluster update settings API.

<block>

(Required, string) Block type to add to the index.

Valid values for <block>
metadata
Disable metadata changes, such as closing the index.
read
Disable read operations.
read_only
Disable write operations and metadata changes.
write
Disable write operations. However, metadata changes are still allowed.

Query parametersedit

allow_no_indices

(Optional, boolean) If false, the request returns an error when a wildcard expression, index alias, or _all value targets only missing or closed indices.

Defaults to true.

expand_wildcards

(Optional, string) Controls what kind of indices that wildcard expressions can expand to. Multiple values are accepted when separated by a comma, as in open,hidden. Valid values are:

all
Expand to open and closed indices, including hidden indices.
open
Expand only to open indices.
closed
Expand only to closed indices.
hidden
Expansion of wildcards will include hidden indices. Must be combined with open, closed, or both.
none
Wildcard expressions are not accepted.

Defaults to open.

ignore_unavailable
(Optional, boolean) If true, missing or closed indices are not included in the response. Defaults to false.
master_timeout
(Optional, time units) Specifies the period of time 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. Defaults to 30s.
timeout
(Optional, time units) Specifies the period of time to wait for a response. If no response is received before the timeout expires, the request fails and returns an error. Defaults to 30s.

Examplesedit

The following example shows how to add an index block:

PUT /my-index-000001/_block/write

The API returns following response:

{
  "acknowledged" : true,
  "shards_acknowledged" : true,
  "indices" : [ {
    "name" : "my-index-000001",
    "blocked" : true
  } ]
}