6.5. Elasticsearch Connector#

Overview
Configuration
Configuration Properties
TLS Security
Data Types
Special Columns
Full Text Queries
AWS Authorization

Overview#

The Elasticsearch Connector allows access to Elasticsearch data from Presto. This document describes how to setup the Elasticsearch Connector to run SQL queries against Elasticsearch.

Note

Elasticsearch 6.0.0 or later is required.

Configuration#

To configure the Elasticsearch connector, create a catalog properties file etc/catalog/elasticsearch.properties with the following contents, replacing the properties as appropriate:

connector.name=elasticsearch
elasticsearch.host=localhost
elasticsearch.port=9200
elasticsearch.default-schema-name=default

Configuration Properties#

The following configuration properties are available:

Property Name	Description
`elasticsearch.host`	Host name of the Elasticsearch server.
`elasticsearch.port`	Port of the Elasticsearch server.
`elasticsearch.default-schema-name`	Default schema name for tables.
`elasticsearch.scroll-size`	Maximum number of hits to be returned with each Elasticsearch scroll request.
`elasticsearch.scroll-timeout`	Timeout for keeping the search context alive for scroll requests.
`elasticsearch.request-timeout`	Timeout for Elasticsearch requests.
`elasticsearch.connect-timeout`	Timeout for connections to Elasticsearch hosts.
`elasticsearch.max-retry-time`	Maximum duration across all retry attempts for a single request.
`elasticsearch.node-refresh-interval`	How often to refresh the list of available Elasticsearch nodes.

`elasticsearch.host`#

Specifies the hostname of the Elasticsearch node to connect to.

This property is required.

`elasticsearch.port`#

Specifies the port of the Elasticsearch node to connect to.

This property is optional; the default is 9200.

`elasticsearch.default-schema-name`#

Defines the schema that contains all tables defined without a qualifying schema name.

This property is optional; the default is default.

`elasticsearch.scroll-size`#

This property defines the maximum number of hits that can be returned with each Elasticsearch scroll request.

This property is optional; the default is 1000.

`elasticsearch.scroll-timeout`#

This property defines the amount of time (ms) Elasticsearch keeps the search context alive for scroll requests

This property is optional; the default is 1m.

`elasticsearch.request-timeout`#

This property defines the timeout value for all Elasticsearch requests.

This property is optional; the default is 10s.

`elasticsearch.connect-timeout`#

This property defines the timeout value for all Elasticsearch connection attempts.

This property is optional; the default is 1s.

`elasticsearch.max-retry-time`#

This property defines the maximum duration across all retry attempts for a single request to Elasticsearch.

This property is optional; the default is 20s.

`elasticsearch.node-refresh-interval`#

This property controls how often the list of available Elasticsearch nodes is refreshed.

This property is optional; the default is 1m.

TLS Security#

The Elasticsearch connector provides additional security options to support Elasticsearch clusters that have been configured to use TLS.

The connector supports key stores and trust stores in PEM or Java Key Store (JKS) format. The allowed configuration values are:

Property Name	Description
`elasticsearch.tls.enabled`	Whether TLS security is enabled.
`elasticsearch.tls.verify-hostnames`	Whether to verify Elasticsearch server hostnames.
`elasticsearch.tls.keystore-path`	Path to the PEM or JKS key store.
`elasticsearch.tls.truststore-path`	Path to the PEM or JKS trust store.
`elasticsearch.tls.keystore-password`	Password for the key store.
`elasticsearch.tls.truststore-password`	Password for the trust store.

`elasticsearch.tls.keystore-path`#

The path to the PEM or JKS key store. This file must be readable by the operating system user running Presto.

This property is optional.

`elasticsearch.tls.truststore-path`#

The path to PEM or JKS trust store. This file must be readable by the operating system user running Presto.

This property is optional.

`elasticsearch.tls.keystore-password`#

The key password for the key store specified by elasticsearch.tls.keystore-path.

This property is optional.

`elasticsearch.tls.truststore-password`#

The key password for the trust store specified by elasticsearch.tls.truststore-path.

This property is optional.

Data Types#

The data type mappings are as follows:

Elasticsearch	Presto
`binary`	`VARBINARY`
`boolean`	`BOOLEAN`
`double`	`DOUBLE`
`float`	`REAL`
`byte`	`TINYINT`
`short`	`SMALLINT`
`integer`	`INTEGER`
`long`	`BIGINT`
`keyword`	`VARCHAR`
`text`	`VARCHAR`
`date`	`TIMESTAMP`
`ip`	`IPADDRESS`
(all others)	(unsupported)

Array Types#

Fields in Elasticsearch can contain zero or more values , but there is no dedicated array type. To indicate a field contains an array, it can be annotated in a Presto-specific structure in the _meta section of the index mapping.

For example, you can have an Elasticsearch index that contains documents with the following structure:

{
    "array_string_field": ["presto","is","the","besto"],
    "long_field": 314159265359,
    "id_field": "564e6982-88ee-4498-aa98-df9e3f6b6109",
    "timestamp_field": "1987-09-17T06:22:48.000Z",
    "object_field": {
        "array_int_field": [86,75,309],
        "int_field": 2
    }
}

The array fields of this structure can be defined by using the following command to add the field property definition to the _meta.presto property of the target index mapping.

curl --request PUT \
    --url localhost:9200/doc/_mapping \
    --header 'content-type: application/json' \
    --data '
{
    "_meta": {
        "presto":{
            "array_string_field":{
                "isArray":true
            },
            "object_field":{
                "array_int_field":{
                    "isArray":true
                }
            },
        }
    }
}'

Special Columns#

The following hidden columns are available:

Column	Description
_id	The Elasticsearch document ID
_score	The document score returned by the Elasticsearch query
_source	The source of the original document

Full Text Queries#

Presto SQL queries can be combined with Elasticsearch queries by providing the full text query as part of the table name, separated by a colon. For example:

SELECT * FROM "tweets: +presto SQL^2"

AWS Authorization#

To enable AWS authorization using IAM policies, the elasticsearch.security option needs to be set to AWS. Additionally, the following options need to be configured appropriately:

Property Name	Description
`elasticsearch.aws.region`	AWS region or the Elasticsearch endpoint. This option is required.
`elasticsearch.aws.access-key`	AWS access key to use to connect to the Elasticsearch domain.
`elasticsearch.aws.secret-key`	AWS secret key to use to connect to the Elasticsearch domain.

Presto 334 Documentation