Elasticsearch Connector

• Overview

• Configuration

• Configuration Properties

• TLS Security

• Data Types

• Special Columns

• Full Text Queries

• Pass-through 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:

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 will contain 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 Elasticsearch will keep the search context alive for scroll requests

This property is optional; the default is 1m.

elasticsearch.max-hits

This property defines the maximum number of hits an Elasticsearch request can fetch.

This property is optional; the default is 1000000.

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.

elasticsearch.max-http-connections

This property controls the maximum number of persistent HTTP connections to Elasticsearch.

This property is optional; the default is 25.

elasticsearch.http-thread-count

This property controls the number of threads handling HTTP connections to Elasticsearch.

This property is optional; the default is number of available processors.

elasticsearch.ignore-publish-address

The address is used to address Elasticsearch nodes. When running in a container environment, the published address may not match the public address of the container. This option makes the connector ignore the published address and use the configured address, instead.

This property is optional; the default is false.

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:

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:

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:

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 elasticsearch.default."tweets: +presto DB^2"

Pass-through Queries

The Elasticsearch connector allows you to embed any valid Elasticsearch query, that uses the Elasticsearch Query DSL in your SQL query.

The results can then be used in any SQL statement, wrapping the Elasticsearch query. The syntax extends the syntax of the enhanced Elasticsearch table names with the following:

SELECT * FROM es.default."<index>$query:<es-query>"

The Elasticsearch query string es-query is base32-encoded to avoid having to deal with escaping quotes and case sensitivity issues in table identifiers.

The result of these query tables is a table with a single row and a single column named result of type VARCHAR. It contains the JSON payload returned by Elasticsearch, and can be processed with the built-in JSON functions.

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: