OpenSearch is the flexible, scalable, open-source way to build solutions for data-intensive applications. For more information about OpenSearch, see OpenSearch official website.

PREMIUM EDITION FEATURE

This is a Premium Edition feature. All Premium Edition features are available out of the box without additional cost on RisingWave Cloud. For self-hosted deployments, users need to purchase a license key to access this feature. To purchase a license key, please contact sales team at sales@risingwave-labs.com.

For a full list of Premium Edition features, see RisingWave Premium Edition.

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Prerequisites

  • Ensure the OpenSearch cluster is accessible from RisingWave.
  • If you are running RisingWave locally from binaries, make sure that you have JDK 11 or later versions installed in your environment.

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Create an OpenSearch sink

Use the following syntax to create an OpenSearch sink. Once a sink is created, any insert or update to the sink will be streamed to the specified OpenSearch endpoint.

CREATE SINK sink_name
[ FROM sink_from | AS select_query ]
WITH (
  connector = 'opensearch',
  primary_key = '<primary key of the sink_from object>',
  { index = '<your opensearch index>' | index_column = '<your index column>' },
  url = 'http://<opensearch hostname>:<opensearch port>',
  username = '<your opensearch username>',
  password = '<your password>',
  delimiter='<delimiter>'
);

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Parameters

ParameterDescription
sink_nameName of the sink to be created.
sink_fromA clause that specifies the direct source from which data will be output. sink_from can be a materialized view or a table. Either this clause or a SELECT query must be specified.
AS select_queryA SELECT query that specifies the data to be output to the sink. Either this query or a FROM clause must be specified. See SELECT for the syntax and examples of the SELECT command.
primary_keyOptional. The primary keys of the sink. If the primary key has multiple columns, set a delimiter in the delimiter parameter below to join them.
indexRequired if index_column is not set. Name of the OpenSearch index that you want to write data to.
index_columnThis parameter enables you to create a sink that writes to multiple indexes dynamically. The sink decides which index to write to based on a column. It is mutually exclusive with the parameter index. Only one of them can and must be set.
  • When index is set, the write index of OpenSearch is index.
  • When index_column is set, the index of OpenSearch is the value of this column, which must be the string type.
Since OpenSearch sink defaults to the first column as the key, it is not recommended to place this column as the first column.
urlRequired. URL of the OpenSearch REST API endpoint.
usernameOptional. opensearch user name for accessing the OpenSearch endpoint. It must be used with password.
passwordOptional. Password for accessing the OpenSearch endpoint. It must be used with username.
delimiterOptional. Delimiter for OpenSearch ID when the sink’s primary key has multiple columns.

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Notes about primary keys and OpenSearch IDs

The OpenSearch sink defaults to the upsert sink type. It does not support the append-only sink type.

To customize your OpenSearch ID, specify it via the primary_key parameter. RisingWave will combine multiple primary key values into a single string with the delimiter set, and use it as the OpenSearch ID.

If you don’t want to customize your OpenSearch ID, RisingWave will use the first column in the sink definition as the OpenSearch ID.

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Data type mapping

OpenSearch uses a mechanism called dynamic field mapping to dynamically create fields and determine their types automatically. It treats all integer types as long and all floating-point types as float. To ensure data types in RisingWave are mapped to the data types in OpenSearch correctly, we recommend that you specify the mapping via index templates.

RisingWave Data TypeOpenSearch Field Type
booleanboolean
smallintlong
integerlong
bigintlong
numerictext
realfloat
double precisionfloat
character varyingtext
byteatext
datedate
time without time zonetext
timestamp without time zonetext
timestamp with time zonetext
intervaltext
structobject
arrayarray
JSONBobject (RisingWave’s OpenSearch sink will send JSONB as a JSON string, and OpenSearch will convert it into an object)

OpenSearch doesn’t require users to explicitly CREATE TABLE. Instead, it infers the schema on-the-fly based on the first record ingested. For example, if a record contains a jsonb {v1: 100}, v1 will be inferred as a long type. However, if the next record is {v1: "abc"}, the ingestion will fail because "abc" is inferred as a string and the two types are incompatible.

This behavior may lead to missing records. For monitoring, see Grafana, where there is a panel for all sink write errors.