Migrate from OpenSearch to Zilliz Cloud

This topic describes how Zilliz Cloud handles data type mapping, collection naming rules, and considerations when migrating from OpenSearch.

Prerequisites

Before starting your OpenSearch to Zilliz Cloud migration, ensure you meet these requirements:

OpenSearch requirements

Requirement	Details
Network access	Source OpenSearch cluster must be accessible from the public internet
Authentication	Valid cluster endpoint, username, and password with necessary permissions
Vector field requirement	Each source index must contain at least one k-NN vector field
Data availability	Source indexes must contain data. Empty indexes cannot be migrated.

Zilliz Cloud requirements

Requirement	Details
User role	Organization Owner or Project Admin
Cluster capacity	Sufficient storage and compute resources (use the CU calculator to estimate CU size)
Network access	Add Zilliz Cloud IPs to allowlists if using network restrictions

Data type mapping

The following table summarizes how field types in OpenSearch are mapped to Zilliz Cloud field types, along with details on any customization options.

OpenSearch Field Type	Zilliz Cloud Field Type	Description
Primary key	Primary key	OpenSearch's primary key (_id) is automatically mapped as the primary key in Zilliz Cloud. When migrating data, you can enable Auto ID. However, if you do so, the original primary key values from your source table will be discarded.
k-NN vector	FLOAT_VECTOR	The `float` vector type from OpenSearch is mapped to `FLOAT_VECTOR` on Zilliz Cloud. Byte/Binary vectors from OpenSearch are not supported for migration. Vector dimensions remain unchanged.
Alias	Not supported	Alias fields are not supported.
Binary	VARCHAR	Binary data is stored as a string on Zilliz Cloud.
Numeric
`byte`	INT8	Directly mapped.
`double`	DOUBLE	Directly mapped.
`float`	FLOAT	Directly mapped.
`half_float`	FLOAT	Mapped to `FLOAT`.
`integer`	INT32	Directly mapped.
`long`	INT64	Directly mapped.
`short`	INT16	Directly mapped.
`unsigned_long`	Not supported	Not supported on Zilliz Cloud.
`scaled_float`	Not supported	Not supported on Zilliz Cloud.
Boolean	BOOL	Stores `true` or `false`.
Date	VARCHAR	Stored as a string. Ensure correct format conversion.
IP address	VARCHAR	Stored as a string.
Range	JSON	Stored in JSON format.
Object
`object`	JSON	Stored in JSON format.
`nested`	JSON	Stored in JSON format.
`flat_object`	JSON	Stored in JSON format.
`join`	VARCHAR	Stored as a string.
String
`keyword`	VARCHAR	Stored as a string.
`text`	VARCHAR	Mapped to `VARCHAR` .
`match_only_text`	VARCHAR	Stored as a string.
`token_count`	INT32	Stored as INT32.
`wildcard`	Not supported	Not supported on Zilliz Cloud.
Autocomplete	VARCHAR	Stored as a string.
Geographic	VARCHAR	Stored as a string.
Rank	VARCHAR	Stored as a string.
Percolator	VARCHAR	Stored as a string.
Derived	Not supported	Derived fields are not supported on Zilliz Cloud.
Star-tree	Not supported	Star-tree fields are not supported on Zilliz Cloud.
Arrays	Not supported	Arrays are not supported for migration.
Multifields	Not supported	Multifields are not supported for migration.

OpenSearch-specific handling rules

Collection naming rules

OpenSearch index names are transferred to Zilliz Cloud with the following considerations:

Scenario	Impact	Solution
Default naming	Collection names match source index names exactly	Names are preserved as-is from OpenSearch
Special characters	Index names with hyphens (-) or dots (.) will cause errors and prevent job submission	Manually rename indexes to use underscores or other valid characters
Naming conflicts	Cannot submit job if a collection with the same name already exists	Delete existing collection, choose a different database, or rename during migration configuration

Migration considerations

The following features are not supported for OpenSearch migration:

Limitation	Impact	Alternative
Dynamic to fixed field conversion	Cannot convert existing dynamic fields to fixed types	Fields maintain their original dynamic nature
Add more fields	Cannot add new fields during migration	Only existing Elasticsearch fields are migrated
Sparse vectors	Not supported in current release	Consider dense vector alternatives or contact support for roadmap

Prerequisites​

OpenSearch requirements​

Zilliz Cloud requirements​

Data type mapping​

OpenSearch-specific handling rules​

Collection naming rules​

Migration considerations​