Data Migration Overview

The DCS console supports online migration (in full or incrementally) and backup migration (by importing backup files) with intuitive operations.

Backup migration is suitable when the source and target Redis instances are not connected, and the source Redis instance does not support the SYNC and PSYNC commands. To migrate data, import your backup files to OBS, and DCS will read data from OBS and migrate the data to the target DCS Redis instance. Alternatively, you can import the backup files directly to the DCS instance.
Online migration is suitable when the source Redis instance supports the SYNC and PSYNC commands. Data in the source Redis instance can be migrated in full or incrementally to the target instance.
During online migration, the PSYNC command is delivered to the source address. For details about how this works, see the replication explanation. This command will cause a fork operation at the source end, which affects latency. For details about the impact scope, see the Redis official website.

Currently, the data migration function is free of charge in the OBT. You will be notified when data migration starts to be charged.

For more information about migration tools and schemes, see Migration Tools and Schemes.

**Table 1** DCS data migration modes
Migration Mode	Source	Target: DCS
Migration Mode	Source	Single-Node, Read/Write Splitting, or Master/Standby	Proxy Cluster	Redis Cluster
Importing backup files	AOF file	√	√	√
Importing backup files	RDB file	√	√	√
Migrating data online	DCS for Redis: Single-node, read/write splitting, or master/standby	√	√	√
	DCS for Redis: Proxy Cluster	√	√	√
	DCS for Redis: Redis Cluster	√	√	√
	Self-hosted Redis	√	√	√
	Other cloud Redis	√	√	√
	NOTE: You can migrate data online in full or incrementally from other cloud Redis to DCS for Redis if they are connected and the SYNC and PSYNC commands can be run on the source Redis. However, some instances provided by other cloud vendors may fail to be migrated online. In this case, migrate data through backup import or use other migration schemes. For details, see Migration Tools and Schemes.

DCS for Redis refers to Redis instances provided by DCS.
Self-hosted Redis refers to self-hosted Redis on the cloud, from other cloud vendors, or in on-premises data centers.
Other cloud Redis refers to Redis services provided by other cloud vendors.
√: Supported. ×: Not supported.