原文地址: https://www.elastic.co/guide/en/elasticsearch/reference/7.7/docs-index_.html, 原文档版权归 www.elastic.co 所有

Index APIedit

Adds a JSON document to the specified index and makes it searchable. If the document already exists, updates the document and increments its version.

Requestedit

PUT /<index>/_doc/<_id>

POST /<index>/_doc/

PUT /<index>/_create/<_id>

POST /<index>/_create/<_id>

Path parametersedit

<index>
(Required, string) Name of the target index. By default, the index is created automatically if it doesn’t exist. For more information, see Create indices automatically.
<_id>
(Optional, string) Unique identifier for the document. Required if you are using a PUT request. Omit to automatically generate an ID when using a POST request.

Query parametersedit

if_seq_no
(Optional, integer) Only perform the operation if the document has this sequence number. See Optimistic concurrency control.
if_primary_term
(Optional, integer) Only perform the operation if the document has this primary term. See Optimistic concurrency control.
op_type
(Optional, enum) Set to create to only index the document if it does not already exist (put if absent). If a document with the specified _id already exists, the indexing operation will fail. Same as using the <index>/_create endpoint. Valid values: index, create. If document id is specified, it defaults to index. Otherwise, it defaults to create.
pipeline
(Optional, string) ID of the pipeline to use to preprocess incoming documents.
refresh
(Optional, enum) If true, Elasticsearch refreshes the affected shards to make this operation visible to search, if wait_for then wait for a refresh to make this operation visible to search, if false do nothing with refreshes. Valid values: true, false, wait_for. Default: false.
routing
(Optional, string) Target the specified primary shard.
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.
version
(Optional, integer) Explicit version number for concurrency control. The specified version must match the current version of the document for the request to succeed.
version_type
(Optional, enum) Specific version type: internal, external, external_gte.
wait_for_active_shards

(Optional, string) The number of shard copies that must be active before proceeding with the operation. Set to all or any positive integer up to the total number of shards in the index (number_of_replicas+1). Default: 1, the primary shard.

See Active shards.

Request bodyedit

<field>
(Required, string) Request body contains the JSON source for the document data.

Response bodyedit

_shards
Provides information about the replication process of the index operation.
_shards.total
Indicates how many shard copies (primary and replica shards) the index operation should be executed on.
_shards.successful

Indicates the number of shard copies the index operation succeeded on. When the index operation is successful, successful is at least 1.

Replica shards might not all be started when an indexing operation returns successfully—​by default, only the primary is required. Set wait_for_active_shards to change this default behavior. See Active shards.

_shards.failed
An array that contains replication-related errors in the case an index operation failed on a replica shard. 0 indicates there were no failures.
_index
The name of the index the document was added to.
_type
The document type. Elasticsearch indices now support a single document type, _doc.
_id
The unique identifier for the added document.
_version
The document version. Incremented each time the document is updated.
_seq_no
The sequence number assigned to the document for the indexing operation. Sequence numbers are used to ensure an older version of a document doesn’t overwrite a newer version. See Optimistic concurrency control.
_primary_term
The primary term assigned to the document for the indexing operation. See Optimistic concurrency control.
result
The result of the indexing operation, created or updated.

Descriptionedit

You can index a new JSON document with the _doc or _create resource. Using _create guarantees that the document is only indexed if it does not already exist. To update an existing document, you must use the _doc resource.

Create indices automaticallyedit

If the specified index does not already exist, by default the index operation automatically creates it and applies any configured index templates. If no mapping exists, the index operation creates a dynamic mapping. By default, new fields and objects are automatically added to the mapping if needed. For more information about field mapping, see mapping and the put mapping API.

Automatic index creation is controlled by the action.auto_create_index setting. This setting defaults to true, which allows any index to be created automatically. You can modify this setting to explicitly allow or block automatic creation of indices that match specified patterns, or set it to false to disable automatic index creation entirely. Specify a comma-separated list of patterns you want to allow, or prefix each pattern with + or - to indicate whether it should be allowed or blocked. When a list is specified, the default behaviour is to disallow.

PUT _cluster/settings
{
    "persistent": {
        "action.auto_create_index": "twitter,index10,-index1*,+ind*" 
    }
}

PUT _cluster/settings
{
    "persistent": {
        "action.auto_create_index": "false" 
    }
}

PUT _cluster/settings
{
    "persistent": {
        "action.auto_create_index": "true" 
    }
}

Allow auto-creation of indices called twitter or index10, block the creation of indices that match the pattern index1*, and allow creation of any other indices that match the ind* pattern. Patterns are matched in the order specified.

Disable automatic index creation entirely.

Allow automatic creation of any index. This is the default.

Put if absentedit

You can force a create operation by using the _create resource or setting the op_type parameter to create. In this case, the index operation fails if a document with the specified ID already exists in the index.

Create document IDs automaticallyedit

If you don’t specify a document ID when using POST, the op_type is automatically set to create and the index operation generates a unique ID for the document.

POST twitter/_doc/
{
    "user" : "kimchy",
    "post_date" : "2009-11-15T14:12:12",
    "message" : "trying out Elasticsearch"
}

The API returns the following result:

{
    "_shards" : {
        "total" : 2,
        "failed" : 0,
        "successful" : 2
    },
    "_index" : "twitter",
    "_type" : "_doc",
    "_id" : "W0tpsmIBdwcYyG50zbta",
    "_version" : 1,
    "_seq_no" : 0,
    "_primary_term" : 1,
    "result": "created"
}
Optimistic concurrency controledit

Index operations can be made conditional and only be performed if the last modification to the document was assigned the sequence number and primary term specified by the if_seq_no and if_primary_term parameters. If a mismatch is detected, the operation will result in a VersionConflictException and a status code of 409. See Optimistic concurrency control for more details.

Routingedit

By default, shard placement — or routing — is controlled by using a hash of the document’s id value. For more explicit control, the value fed into the hash function used by the router can be directly specified on a per-operation basis using the routing parameter. For example:

POST twitter/_doc?routing=kimchy
{
    "user" : "kimchy",
    "post_date" : "2009-11-15T14:12:12",
    "message" : "trying out Elasticsearch"
}

In this example, the document is routed to a shard based on the routing parameter provided: "kimchy".

When setting up explicit mapping, you can also use the _routing field to direct the index operation to extract the routing value from the document itself. This does come at the (very minimal) cost of an additional document parsing pass. If the _routing mapping is defined and set to be required, the index operation will fail if no routing value is provided or extracted.

Distributededit

The index operation is directed to the primary shard based on its route (see the Routing section above) and performed on the actual node containing this shard. After the primary shard completes the operation, if needed, the update is distributed to applicable replicas.

Active shardsedit

To improve the resiliency of writes to the system, indexing operations can be configured to wait for a certain number of active shard copies before proceeding with the operation. If the requisite number of active shard copies are not available, then the write operation must wait and retry, until either the requisite shard copies have started or a timeout occurs. By default, write operations only wait for the primary shards to be active before proceeding (i.e. wait_for_active_shards=1). This default can be overridden in the index settings dynamically by setting index.write.wait_for_active_shards. To alter this behavior per operation, the wait_for_active_shards request parameter can be used.

Valid values are all or any positive integer up to the total number of configured copies per shard in the index (which is number_of_replicas+1). Specifying a negative value or a number greater than the number of shard copies will throw an error.

For example, suppose we have a cluster of three nodes, A, B, and C and we create an index index with the number of replicas set to 3 (resulting in 4 shard copies, one more copy than there are nodes). If we attempt an indexing operation, by default the operation will only ensure the primary copy of each shard is available before proceeding. This means that even if B and C went down, and A hosted the primary shard copies, the indexing operation would still proceed with only one copy of the data. If wait_for_active_shards is set on the request to 3 (and all 3 nodes are up), then the indexing operation will require 3 active shard copies before proceeding, a requirement which should be met because there are 3 active nodes in the cluster, each one holding a copy of the shard. However, if we set wait_for_active_shards to all (or to 4, which is the same), the indexing operation will not proceed as we do not have all 4 copies of each shard active in the index. The operation will timeout unless a new node is brought up in the cluster to host the fourth copy of the shard.

It is important to note that this setting greatly reduces the chances of the write operation not writing to the requisite number of shard copies, but it does not completely eliminate the possibility, because this check occurs before the write operation commences. Once the write operation is underway, it is still possible for replication to fail on any number of shard copies but still succeed on the primary. The _shards section of the write operation’s response reveals the number of shard copies on which replication succeeded/failed.

{
    "_shards" : {
        "total" : 2,
        "failed" : 0,
        "successful" : 2
    }
}
Refreshedit

Control when the changes made by this request are visible to search. See refresh.

Noop updatesedit

When updating a document using the index API a new version of the document is always created even if the document hasn’t changed. If this isn’t acceptable use the _update API with detect_noop set to true. This option isn’t available on the index API because the index API doesn’t fetch the old source and isn’t able to compare it against the new source.

There isn’t a hard and fast rule about when noop updates aren’t acceptable. It’s a combination of lots of factors like how frequently your data source sends updates that are actually noops and how many queries per second Elasticsearch runs on the shard receiving the updates.

Timeoutedit

The primary shard assigned to perform the index operation might not be available when the index operation is executed. Some reasons for this might be that the primary shard is currently recovering from a gateway or undergoing relocation. By default, the index operation will wait on the primary shard to become available for up to 1 minute before failing and responding with an error. The timeout parameter can be used to explicitly specify how long it waits. Here is an example of setting it to 5 minutes:

PUT twitter/_doc/1?timeout=5m
{
    "user" : "kimchy",
    "post_date" : "2009-11-15T14:12:12",
    "message" : "trying out Elasticsearch"
}
Versioningedit

Each indexed document is given a version number. By default, internal versioning is used that starts at 1 and increments with each update, deletes included. Optionally, the version number can be set to an external value (for example, if maintained in a database). To enable this functionality, version_type should be set to external. The value provided must be a numeric, long value greater than or equal to 0, and less than around 9.2e+18.

When using the external version type, the system checks to see if the version number passed to the index request is greater than the version of the currently stored document. If true, the document will be indexed and the new version number used. If the value provided is less than or equal to the stored document’s version number, a version conflict will occur and the index operation will fail. For example:

PUT twitter/_doc/1?version=2&version_type=external
{
    "message" : "elasticsearch now has versioning support, double cool!"
}

Versioning is completely real time, and is not affected by the near real time aspects of search operations. If no version is provided, then the operation is executed without any version checks.

In the previous example, the operation will succeed since the supplied version of 2 is higher than the current document version of 1. If the document was already updated and its version was set to 2 or higher, the indexing command will fail and result in a conflict (409 http status code).

A nice side effect is that there is no need to maintain strict ordering of async indexing operations executed as a result of changes to a source database, as long as version numbers from the source database are used. Even the simple case of updating the Elasticsearch index using data from a database is simplified if external versioning is used, as only the latest version will be used if the index operations arrive out of order for whatever reason.

Version typesedit

In addition to the external version type, Elasticsearch also supports other types for specific use cases:

internal
Only index the document if the given version is identical to the version of the stored document.
external or external_gt
Only index the document if the given version is strictly higher than the version of the stored document or if there is no existing document. The given version will be used as the new version and will be stored with the new document. The supplied version must be a non-negative long number.
external_gte
Only index the document if the given version is equal or higher than the version of the stored document. If there is no existing document the operation will succeed as well. The given version will be used as the new version and will be stored with the new document. The supplied version must be a non-negative long number.

The external_gte version type is meant for special use cases and should be used with care. If used incorrectly, it can result in loss of data. There is another option, force, which is deprecated because it can cause primary and replica shards to diverge.

Examplesedit

Insert a JSON document into the twitter index with an _id of 1:

PUT twitter/_doc/1
{
    "user" : "kimchy",
    "post_date" : "2009-11-15T14:12:12",
    "message" : "trying out Elasticsearch"
}

The API returns the following result:

{
    "_shards" : {
        "total" : 2,
        "failed" : 0,
        "successful" : 2
    },
    "_index" : "twitter",
    "_type" : "_doc",
    "_id" : "1",
    "_version" : 1,
    "_seq_no" : 0,
    "_primary_term" : 1,
    "result" : "created"
}

Use the _create resource to index a document into the twitter index if no document with that ID exists:

PUT twitter/_create/1
{
    "user" : "kimchy",
    "post_date" : "2009-11-15T14:12:12",
    "message" : "trying out Elasticsearch"
}

Set the op_type parameter to create to index a document into the twitter index if no document with that ID exists:

PUT twitter/_doc/1?op_type=create
{
    "user" : "kimchy",
    "post_date" : "2009-11-15T14:12:12",
    "message" : "trying out Elasticsearch"
}