Network Conditions for Accessing DCS Redis

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

There are different constraints when a client connects to Redis in certain ways:

• Accessing a Redis instance on a client within the same VPC

  The ECS where the 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: 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 4.0/5.0/6.0: The IP address of the ECS must be on the whitelist of the DCS instance.

• Accessing a Redis instance on a client across VPCs in the same region

  If the client 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?" in Distributed Cache Service User Guide > FAQs.

• Accessing a Redis instance of another region on a client

  If the client server and the Redis instance are not in the same region, connect the network using Direct Connect. For details, see Direct Connect User Guide.

  To access a Redis instance across regions, the instance domain names cannot be resolved across regions. Therefore, the instance cannot be accessed at its domain name addresses. You can manually map the domain name to the IP address in the hosts file, or access the instance at its IP address.

Others:

Ensure that the security group and network ACL of the Redis client allow inbound access to the Redis server. Otherwise, Redis connections may become unstable.