# Using Redis OSS as a target for AWS Database Migration Service
Redis OSS is an open-source in-memory data structure store used as a database, cache, and message broker. Managing data in-memory can result in read or write operations taking less than a millisecond, and hundreds of millions of operations performed each second. As an in-memory data store, Redis OSS powers the most demanding applications requiring sub-millisecond response times.
Using AWS DMS, you can migrate data from any supported source database to a target Redis OSS data store with minimal downtime. For additional information about Redis OSS see, [Redis OSS Documentation](https://redis.io/documentation).
In addition to on-premises Redis OSS, AWS Database Migration Service supports the following:
+ [Amazon ElastiCache (Redis OSS)](https://aws.amazon.com/elasticache/redis/) as a target data store. ElastiCache (Redis OSS) works with your Redis OSS clients and uses the open Redis OSS data format to store your data.
+ [Amazon MemoryDB](https://aws.amazon.com/memorydb/) as a target data store. MemoryDB is compatible with Redis OSS and enables you to build applications using all the Redis OSS data structures, APIs, and commands in use today.
For additional information about working with Redis OSS as a target for AWS DMS, see the following sections:
**Topics**
+ [Prerequisites for using a Redis OSS cluster as a target for AWS DMS](#CHAP_Target.Redis.Prerequisites)
+ [Limitations when using Redis as a target for AWS Database Migration Service](#CHAP_Target.Redis.Limitations)
+ [Migrating data from a relational or non-relational database to a Redis OSS target](#CHAP_Target.Redis.Migrating)
+ [Specifying endpoint settings for Redis OSS as a target](#CHAP_Target.Redis.EndpointSettings)
## Prerequisites for using a Redis OSS cluster as a target for AWS DMS
DMS supports an on-premises Redis OSS target in a standalone configuration, or as a Redis OSS cluster where data is automatically *sharded* across multiple nodes. Sharding is the process of separating data into smaller chunks called shards that are spread across multiple servers or nodes. In effect, a shard is a data partition that contains a subset of the total data set, and serves a slice of the overall workload.
Since Redis OSS is a key-value NoSQL data store, the Redis OSS key naming convention to use when your source is a relational database, is **schema-name.table-name.primary-key**. In Redis OSS, the key and value must not contain the special character %. Otherwise, DMS skips the record.
**Note**
If you are using ElastiCache (Redis OSS) as a target, DMS supports *cluster mode enabled* configurations only. For more information about using ElastiCache (Redis OSS) version 6.x or higher to create a cluster mode enabled target data store, see [Getting started](https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/GettingStarted.html) in the *Amazon ElastiCache (Redis OSS) User Guide*.
Before you begin a database migration, launch your Redis OSS cluster with the following criteria.
+ Your cluster has one or more shards.
+ If you're using an ElastiCache (Redis OSS) target, ensure that your cluster doesn't use IAM role-based access control. Instead, use Redis OSS Auth to authenticate users.
+ Enable Multi-AZ (Availability Zones).
+ Ensure the cluster has sufficient memory available to fit the data to be migrated from your database.
+ Make sure that your target Redis OSS cluster is clear of all data before starting the initial migration task.
You should determine your security requirements for the data migration prior to creating your cluster configuration. DMS supports migration to target replication groups regardless of their encryption configuration. But you can enable or disable encryption only when you create your cluster configuration.
## Limitations when using Redis as a target for AWS Database Migration Service
The following limitations apply when using Redis OSS as a target:
+ Since Redis OSS is a key-value no-sql data store, the Redis OSS key naming convention to use when your source is a relational database, is `schema-name.table-name.primary-key`.
+ In Redis OSS, the key-value can't contain the special character `%`. Otherwise, DMS skips the record.
+ DMS won't migrate rows that contain the `%` character.
+ DMS won't migrate fields that contain the `%` character in the field name.
+ Full LOB mode is not supported.
+ A private Certificate Authority (CA) isn’t supported when using ElastiCache (Redis OSS) as a target.
+ AWS DMS does not support source data containing embedded `'\0'` characters when using Redis as a target endpoint. Data containing embedded `'\0'` characters will be truncated at the first `'\0'` character.
## Migrating data from a relational or non-relational database to a Redis OSS target
You can migrate data from any source SQL or NoSQL data store directly to a Redis OSS target. Setting up and starting a migration to a Redis OSS target is similar to any full load and change data capture migration using the DMS console or API. To perform a database migration to a Redis OSS target, you do the following.
+ Create a replication instance to perform all the processes for the migration. For more information, see [Creating a replication instance](CHAP_ReplicationInstance.Creating.md).
+ Specify a source endpoint. For more information, see [Creating source and target endpoints](CHAP_Endpoints.Creating.md).
+ Locate the DNS name and port number of your cluster.
+ Download a certificate bundle that you can use to verify SSL connections.
+ Specify a target endpoint, as described below.
+ Create a task or set of tasks to define what tables and replication processes you want to use. For more information, see [Creating a task](CHAP_Tasks.Creating.md).
+ Migrate data from your source database to your target cluster.
You begin a database migration in one of two ways:
1. You can choose the AWS DMS console and perform each step there.
1. You can use the AWS Command Line Interface (AWS CLI). For more information about using the CLI with AWS DMS, see [AWS CLI for AWS DMS](http://docs.aws.amazon.com/cli/latest/reference/dms/index.html).
**To locate the DNS name and port number of your cluster**
+ Use the following AWS CLI command to provide the `replication-group-id` with the name of your replication group.
```
aws elasticache describe-replication-groups --replication-group-id myreplgroup
```
Here, the output shows the DNS name in the `Address` attribute and the port number in the `Port` attribute of the primary node in the cluster.
```
...
"ReadEndpoint": {
"Port": 6379,
"Address": "myreplgroup-
111.1abc1d.1111.uuu1.cache.example.com"
}
...
```
If you are using MemoryDB as your target, use the following AWS CLI command to provide an endpoint address to your Redis OSS cluster.
```
aws memorydb describe-clusters --clusterid clusterid
```
**Download a certificate bundle for use to verify SSL connections**
+ Enter the following `wget` command at the command line. Wget is a free GNU command-line utility tool used to download files from the internet.
```
wget https://s3.aws-api-domain/rds-downloads/rds-combined-ca-bundle.pem
```
Here, `aws-api-domain` completes the Amazon S3 domain in your AWS Region required to access the specified S3 bucket and the rds-combined-ca-bundle.pem file that it provides.
**To create a target endpoint using the AWS DMS console**
This endpoint is for your Redis OSS target that is already running.
+ On the console, choose **Endpoints** from the navigation pane and then choose **Create Endpoint**. The following table describes the settings.
[\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/dms/latest/userguide/CHAP_Target.Redis.html)
When you're finished providing all information for your endpoint, AWS DMS creates your Redis OSS target endpoint for use during database migration.
For information about creating a migration task and starting your database migration, see [Creating a task](CHAP_Tasks.Creating.md).
## Specifying endpoint settings for Redis OSS as a target
To create or modify a target endpoint, you can use the console or the `CreateEndpoint` or `ModifyEndpoint` API operations.
For a Redis OSS target in the AWS DMS console, specify **Endpoint-specific settings** on the **Create endpoint** or **Modify endpoint** console page.
When using `CreateEndpoint` and `ModifyEndpoint` API operations, specify request parameters for the `RedisSettings` option. The example following shows how to do this using the AWS CLI.
```
aws dms create-endpoint --endpoint-identifier my-redis-target
--endpoint-type target --engine-name redis --redis-settings
'{"ServerName":"sample-test-sample.zz012zz.cluster.eee1.cache.bbbxxx.com","Port":6379,"AuthType":"auth-token",
"SslSecurityProtocol":"ssl-encryption", "AuthPassword":"notanactualpassword"}'
{
"Endpoint": {
"EndpointIdentifier": "my-redis-target",
"EndpointType": "TARGET",
"EngineName": "redis",
"EngineDisplayName": "Redis",
"TransferFiles": false,
"ReceiveTransferredFiles": false,
"Status": "active",
"KmsKeyId": "arn:aws:kms:us-east-1:999999999999:key/x-b188188x",
"EndpointArn": "arn:aws:dms:us-east-1:555555555555:endpoint:ABCDEFGHIJKLMONOPQRSTUVWXYZ",
"SslMode": "none",
"RedisSettings": {
"ServerName": "sample-test-sample.zz012zz.cluster.eee1.cache.bbbxxx.com",
"Port": 6379,
"SslSecurityProtocol": "ssl-encryption",
"AuthType": "auth-token"
}
}
}
```
The `--redis-settings` parameters follow:
+ `ServerName`–(Required) Of type `string`, specifies the Redis OSS cluster that data will be migrated to, and is in your same VPC.
+ `Port`–(Required) Of type `number`, the port value used to access the endpoint.
+ `SslSecurityProtocol`–(Optional) Valid values include `plaintext` and `ssl-encryption`. The default is `ssl-encryption`.
The `plaintext` option doesn't provide Transport Layer Security (TLS) encryption for traffic between endpoint and database.
Use `ssl-encryption` to make an encrypted connection. `ssl-encryption` doesn’t require an SSL Certificate Authority (CA) ARN to verify a server’s certificate, but one can be identified optionally using the `SslCaCertificateArn` setting. If a certificate authority ARN isn't given, DMS uses the Amazon root CA.
When using an on-premises Redis OSS target, you can use `SslCaCertificateArn` to import public or private Certificate Authority (CA) into DMS, and provide that ARN for server authentication. A private CA isn’t supported when using ElastiCache (Redis OSS) as a target.
+ `AuthType`–(Required) Indicates the type of authentication to perform when connecting to Redis OSS. Valid values include `none`, `auth-token`, and `auth-role`.
The `auth-token` option requires an "*AuthPassword*" be provided, while the `auth-role` option requires "*AuthUserName*" and "*AuthPassword*" be provided.