Help Center> Distributed Cache Service> User Guide> Accessing a DCS Redis Instance> Restrictions
Updated on 2023-10-24 GMT+08:00
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Restrictions

You can access a DCS instance through any Redis client. For details about Redis clients, see the Redis official website.

DCS for Redis 3.0 is no longer provided. You can use DCS for Redis 4.0 or later instead.

  • To access a DCS Redis instance through a client on an ECS in the same VPC as the instance, note that:
    • The ECS where the Redis client is installed must be in the same VPC as the DCS Redis instance. An ECS and a DCS instance can communicate with each other only when they belong to the same VPC. Redis 3.0 and 6.0 professional: The instance and the ECS must either be configured with the same security group or use different security groups but can communicate with each other as configured by the security group rules. Redis 4.0/5.0: The IP address of the ECS must be on the whitelist of the DCS instance.

      For details about how to configure a security group, see How Do I Configure a Security Group?

    • If the ECS and DCS Redis instance are not in the same VPC, connect them by establishing a VPC peering connection. For details, see Does DCS Support Cross-VPC Access?
  • Before accessing a DCS Redis 3.0 instance over public networks, ensure that:

    Security group rules have been correctly configured for the instance. If SSL encryption is disabled, allow public access through port 6379. If SSL encryption is enabled, allow public access through port 36379. For details, see the "How Do I Configure a Security Group?" FAQ.

  • Domain names cannot be resolved across regions. If the client and the DCS Redis instance are not in the same region, the instance cannot be accessed at its domain name address. You can manually map the domain name to the IP address in the hosts file or access the instance at its IP address.