• Plugin version: v4.2.0 (Other versions)
• Released on: 2025-05-07
• Changelog

For questions about the plugin, open a topic in theDiscuss forums. For bugs or feature requests, open an issue inGithub. For the list of Elastic supported plugins, please consult theElastic Support Matrix.

Search Elasticsearch for a previous log event and copy some fields from it into the current event. Below are two complete examples of how this filter might be used.

The first example uses the legacyquery parameter where the user is limited to an Elasticsearch query_string. Whenever logstash receives an "end" event, it uses this elasticsearch filter to find the matching "start" event based on some operation identifier. Then it copies the@timestamp field from the "start" event into a new field on the "end" event. Finally, using a combination of the "date" filter and the "ruby" filter, we calculate the time duration in hours between the two events.

if [type] == "end" {   elasticsearch {      hosts => ["es-server"]      query => "type:start AND operation:%{[opid]}"      fields => { "@timestamp" => "started" }   }   date {      match => ["[started]", "ISO8601"]      target => "[started]"   }   ruby {      code => "event.set('duration_hrs', (event.get('@timestamp') - event.get('started')) / 3600)"   }}

The example below reproduces the above example but utilises the query_template. This query_template represents a full Elasticsearch query DSL and supports the standard Logstash field substitution syntax. The example below issues the same query as the first example but uses the template shown.

if [type] == "end" {      elasticsearch {         hosts => ["es-server"]         query_template => "template.json"         fields => { "@timestamp" => "started" }      }      date {         match => ["[started]", "ISO8601"]         target => "[started]"      }      ruby {         code => "event.set('duration_hrs', (event.get('@timestamp') - event.get('started')) / 3600)"      }}

template.json:

{  "size": 1,  "sort" : [ { "@timestamp" : "desc" } ],  "query": {    "query_string": {      "query": "type:start AND operation:%{[opid]}"    }  },  "_source": ["@timestamp"]}

As illustrated above, through the use ofopid, fields from the Logstash events can be referenced within the template. The template will be populated per event prior to being used to query Elasticsearch.

Notice also that when you usequery_template, the Logstash attributesresult_size andsort will be ignored. They should be specified directly in the JSON template, as shown in the example above.

Authentication to a secure Elasticsearch cluster is possible usingone of the following options:

• user ANDpassword
• cloud_auth
• api_key
• ssl_keystore_path and/orssl_keystore_password

Authorization to a secure Elasticsearch cluster requiresread permission at index level andmonitoring permissions at cluster level. Themonitoring permission at cluster level is necessary to perform periodic connectivity checks.

This plugin supports the following configuration options plus theCommon options described later.

As of version4.0.0 of this plugin, a number of previously deprecated settings related to SSL have been removed. Please see theElasticsearch Filter Obsolete Configuration Options for more details.

Also seeCommon options for a list of options supported by all filter plugins.

• Value type ishash

• Default value is{}

• Format:"aggregation_name" => "[path][on][event]":

  • aggregation_name: aggregation name in result from Elasticsearch
  • [path][on][event]: path for where to place the value on the current event, using field-reference notation

A mapping of aggregations to copy into thetarget of the current event.

Example:

filter {  elasticsearch {    aggregation_fields => {      "my_agg_name" => "my_ls_field"    }  }}

• Value type ispassword
• There is no default value for this setting.

Authenticate using Elasticsearch API key. Note that this option also requires enabling thessl_enabled option.

Format isid:api_key whereid andapi_key are as returned by the ElasticsearchCreate API key API.

• Value type isstring, and must contain exactly 64 hexadecimal characters.
• There is no default value for this setting.
• Use of this optionrequires Logstash 8.3+

The SHA-256 fingerprint of an SSL Certificate Authority to trust, such as the autogenerated self-signed CA for an Elasticsearch cluster.

• Value type ispassword
• There is no default value for this setting.

Cloud authentication string ("<username>:<password>" format) is an alternative for theuser/password pair.

For more info, check out theLogstash-to-Cloud documentation.

• Value type isstring
• There is no default value for this setting.

Cloud ID, from the Elastic Cloud web console. If sethosts should not be used.

For more info, check out theLogstash-to-Cloud documentation.

• Value type ishash
• Default value is empty

Pass a set of key value pairs as the headers sent in each request to Elasticsearch. These custom headers will override any headers previously set by the plugin such as the User Agent or Authorization headers.

• Value type ishash

• Default value is{}

• Format:"path.in.source" => "[path][on][event]":

  • path.in.source: field path in document source of result from Elasticsearch, using dot-notation
  • [path][on][event]: path for where to place the value on the current event, using field-reference notation

A mapping of docinfo (_source) fields to copy into thetarget of the current event.

Example:

filter {  elasticsearch {    docinfo_fields => {      "_id" => "document_id"      "_index" => "document_index"    }  }}

• Value type isboolean
• Default value istrue

Whether results should be sorted or not

• Value type isarray

• Default value is{}

• Format:"path.in.result" => "[path][on][event]":

  • path.in.result: field path in indexed result from Elasticsearch, using dot-notation
  • [path][on][event]: path for where to place the value on the current event, using field-reference notation

A mapping of indexed fields to copy into thetarget of the current event.

In the following example, the values of@timestamp andevent_id on the event found via elasticsearch are copied to the current event’sstarted andstart_id fields, respectively:

fields => {  "@timestamp" => "started"  "event_id" => "start_id"}

• Value type isarray
• Default value is["localhost:9200"]

List of elasticsearch hosts to use for querying.

• Value type isstring
• Default value is""

Comma-delimited list of index names to search; use_all or empty string to perform the operation on all indices. Field substitution (e.g.index-name-%{date_field}) is available

• Value type ispassword
• There is no default value for this setting.

Basic Auth - password

• Value type isuri
• There is no default value for this setting.

Set the address of a forward HTTP proxy. An empty string is treated as if proxy was not set, and is useful when using environment variables e.g.proxy => '${LS_PROXY:}'.

• Value type isstring
• There is no default value for this setting.

Elasticsearch query string. More information is available in theElasticsearch query string documentation. Use eitherquery orquery_template.

• Value type isstring
• There is no default value for this setting.

File path to elasticsearch query in DSL format. More information is available in theElasticsearch query documentation. Use eitherquery orquery_template.

• Value type isnumber
• Default value is1

How many results to return

• Value type isnumber
• Default value is0 (retries disabled)

How many times to retry an individual failed request.

When enabled, retry requests that result in connection errors or an HTTP status code included inretry_on_status

• Value type isarray
• Default value is an empty list[]

Which HTTP Status codes to consider for retries (in addition to connection errors) when usingretry_on_failure,

• Value type isstring
• Default value is"@timestamp:desc"

Comma-delimited list of<field>:<direction> pairs that define the sort order

• Value type ispath
• There is no default value for this setting.

SSL certificate to use to authenticate the client. This certificate should be an OpenSSL-style X.509 certificate file.

This setting can be used only ifssl_key is set.

• Value type is a list ofpath
• There is no default value for this setting

The .cer or .pem files to validate the server’s certificate.

You cannot use this setting andssl_truststore_path at the same time.

• Value type is a list ofstring
• There is no default value for this setting

The list of cipher suites to use, listed by priorities. Supported cipher suites vary depending on the Java and protocol versions.

• Value type isboolean
• There is no default value for this setting.

Enable SSL/TLS secured communication to Elasticsearch cluster. Leaving this unspecified will use whatever scheme is specified in the URLs listed inhosts or extracted from thecloud_id. If no explicit protocol is specified plain HTTP will be used.

• Value type ispath
• There is no default value for this setting.

OpenSSL-style RSA private key that corresponds to thessl_certificate.

This setting can be used only ifssl_certificate is set.

• Value type ispassword
• There is no default value for this setting.

Set the keystore password

• Value type ispath
• There is no default value for this setting.

The keystore used to present a certificate to the server. It can be either.jks or.p12

You cannot use this setting andssl_certificate at the same time.

• Value can be any of:jks,pkcs12
• If not provided, the value will be inferred from the keystore filename.

The format of the keystore file. It must be eitherjks orpkcs12.

• Value type isstring
• Allowed values are:'TLSv1.1','TLSv1.2','TLSv1.3'
• Default depends on the JDK being used. With up-to-date Logstash, the default is['TLSv1.2', 'TLSv1.3'].'TLSv1.1' is not considered secure and is only provided for legacy applications.

List of allowed SSL/TLS versions to use when establishing a connection to the Elasticsearch cluster.

For Java 8'TLSv1.3' is supported only since8u262 (AdoptOpenJDK), but requires that you set theLS_JAVA_OPTS="-Djdk.tls.client.protocols=TLSv1.3" system property in Logstash.

If you configure the plugin to use'TLSv1.1' on any recent JVM, such as the one packaged with Logstash, the protocol is disabled by default and needs to be enabled manually by changingjdk.tls.disabledAlgorithms in the$JDK_HOME/conf/security/java.security configuration file. That is,TLSv1.1 needs to be removed from the list.

• Value type ispassword
• There is no default value for this setting.

Set the truststore password

• Value type ispath
• There is no default value for this setting.

The truststore to validate the server’s certificate. It can be either.jks or.p12.

You cannot use this setting andssl_certificate_authorities at the same time.

• Value can be any of:jks,pkcs12
• If not provided, the value will be inferred from the truststore filename.

The format of the truststore file. It must be eitherjks orpkcs12.

• Value can be any of:full,none
• Default value isfull

Defines how to verify the certificates presented by another party in the TLS connection:

full validates that the server certificate has an issue date that’s within the not_before and not_after dates; chains to a trusted Certificate Authority (CA), and has a hostname or IP address that matches the names within the certificate.

none performs no certificate validation.

Setting certificate verification tonone disables many security benefits of SSL/TLS, which is very dangerous. For more information on disabling certificate verification please readhttps://www.cs.utexas.edu/~shmat/shmat_ccs12.pdf

• Value type isarray
• Default value is["_elasticsearch_lookup_failure"]

Tags the event on failure to look up previous log event information. This can be used in later analysis.

• Value type isstring
• There is no default value for this setting.

Define the target field for placing the result data. If this setting is omitted, the target will be the root (top level) of the event.

The destination fields specified infields,aggregation_fields, anddocinfo_fields are relative to this target.

For example, if you want the data to be put in theoperation field:

if [type] == "end" {    filter {      query => "type:start AND transaction:%{[transactionId]}"      elasticsearch {        target => "transaction"        fields => {          "@timestamp" => "started"          "transaction_id" => "id"        }      }    }}

fields fields will be expanded into a data structure in thetarget field, overall shape looks like this:

{  "transaction" => {    "started" => "2025-04-29T12:01:46.263Z"    "id" => "1234567890"  }}

when writing to a field that already exists on the event, the previous value will be overwritten.

• Value type isstring
• There is no default value for this setting.

Basic Auth - username

As of version4.0.0 of this plugin, some configuration options have been replaced. The plugin will fail to start if it contains any of these obsolete options.

These configuration options are supported by all filter plugins:

• Value type ishash
• Default value is{}

If this filter is successful, add any arbitrary fields to this event. Field names can be dynamic and include parts of the event using the%{field}.

Example:

filter {  elasticsearch {    add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }  }}

# You can also add multiple fields at once:filter {  elasticsearch {    add_field => {      "foo_%{somefield}" => "Hello world, from %{host}"      "new_field" => "new_static_value"    }  }}

If the event has field"somefield" == "hello" this filter, on success, would add fieldfoo_hello if it is present, with the value above and the%{host} piece replaced with that value from the event. The second example would also add a hardcoded field.

• Value type isarray
• Default value is[]

If this filter is successful, add arbitrary tags to the event. Tags can be dynamic and include parts of the event using the%{field} syntax.

Example:

filter {  elasticsearch {    add_tag => [ "foo_%{somefield}" ]  }}

# You can also add multiple tags at once:filter {  elasticsearch {    add_tag => [ "foo_%{somefield}", "taggedy_tag"]  }}

If the event has field"somefield" == "hello" this filter, on success, would add a tagfoo_hello (and the second example would of course add ataggedy_tag tag).

• Value type isboolean
• Default value istrue

Disable or enable metric logging for this specific plugin instance by default we record all the metrics we can, but you can disable metrics collection for a specific plugin.

• Value type isstring
• There is no default value for this setting.

Add a uniqueID to the plugin configuration. If no ID is specified, Logstash will generate one. It is strongly recommended to set this ID in your configuration. This is particularly useful when you have two or more plugins of the same type, for example, if you have 2 elasticsearch filters. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

filter {  elasticsearch {    id => "ABC"  }}

• Value type isboolean
• Default value isfalse

Call the filter flush method at regular interval. Optional.

• Value type isarray
• Default value is[]

If this filter is successful, remove arbitrary fields from this event. Fields names can be dynamic and include parts of the event using the %{field} Example:

filter {  elasticsearch {    remove_field => [ "foo_%{somefield}" ]  }}

# You can also remove multiple fields at once:filter {  elasticsearch {    remove_field => [ "foo_%{somefield}", "my_extraneous_field" ]  }}

If the event has field"somefield" == "hello" this filter, on success, would remove the field with namefoo_hello if it is present. The second example would remove an additional, non-dynamic field.

• Value type isarray
• Default value is[]

If this filter is successful, remove arbitrary tags from the event. Tags can be dynamic and include parts of the event using the%{field} syntax.

Example:

filter {  elasticsearch {    remove_tag => [ "foo_%{somefield}" ]  }}

# You can also remove multiple tags at once:filter {  elasticsearch {    remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"]  }}

If the event has field"somefield" == "hello" this filter, on success, would remove the tagfoo_hello if it is present. The second example would remove a sad, unwanted tag as well.