ApsaraDB for Redis

A key value database service that offers in-memory caching and high-speed access to applications hosted on the cloud

ApsaraDB for Redis is an automated and scalable tool for developers to manage data storage shared across multiple processes, applications or servers.

As a Redis protocol compatible tool, ApsaraDB for Redis offers exceptional read-write capabilities and ensures data persistence by using memory and hard disk storage. ApsaraDB for Redis provides data read-write capabilities at high speed by retrieving data from in-memory caches and ensures data persistence by using both memory and hard disk storage mode.

ApsaraDB for Redis supports advanced data structures, which are not readily achievable through databases such as leaderboard, counting, session, and tracking.

Benefits

Easy to use
Easy to use Management Console
Enhanced visibility into queues with monitoring statistics
Scalable
Quickly allows to add or delete storage capacity/cache nodes.
Adjust storage capacity without interrupting application services.
High Availability
Automatically detects node failure and replaces failed nodes.
Offers master-slave dual node backup architecture without service interruptions.
Reliable
Provides high-speed data read-write capabilities.
Ensures persistent data storage using memory and hard disk storage mode.

Features

  • Simple Key Value Storage

    Facilitates quick deployment of services.


    Provides multiple views of monitoring statistics which can be managed from Alibaba Cloud Management Console for hosted Redis.


    Supports multiple data operations to meet complex user requirements.

  • Compatible

    Compatible with all data types defined in open-source Redis protocol, including string, hash, list, set and sorted set.


    Rapidly deploys Redis-compliant cache services.


    Provides infrastructure provisioning and easy maintenance of cache software.


    Compatible with existing tools or clients like Jedis.

  • Elastic Expansion

    One-click storage capacity expansion:

    Allows you to scale storage capacity up or down in real time through Management Console (the function can be enabled with request during the public beta version of the ApsaraDB for Redis).

  • Availability

    Eliminates interruptions caused by single point of failure (SPOF) using master-slave dual node for every instance.


    Automatically detects any kind of failure in hardware and quickly provides recovery options to restore the service.

  • Reliability

    Provides high-speed data read-write capability.


    Ensures persistent data storage by using memory and hard disk storage mode.


    Offers excellent backup services using master and slave dual nodes.

  • Smooth Transaction Operation

    ApsaraDB for Redis supports transaction function defined in the Redis protocol.


    Implements atomic operation, which consists of multiple commands sent from a single client.

  • Advanced Message Notification Mechanism

    Enables message Pub/Sub function by decoupling the publish client and subscribe client based on event notification mechanism.


    Implements interconnections among multiple clients in hosted Redis.

FAQs

1. Does ApsaraDB for Redis support public network access?

No, ApsaraDB for Redis only supports access within the Alibaba Cloud intranet. Only applications deployed on ECS instances can connect to ApsaraDB for Redis hosting for data operations.

2. What is the default data eviction policy of ApsaraDB for Redis?

The default eviction policy of ApsaraDB for Redis is "no eviction". No eviction service will not evict any keys, and no writes will be possible until more memory is freed. You can modify the settings in "Policy Settings" through ApsaraDB for Redis console.

Note: ApsaraDB for Redis adopts volatile-LRU by default, which is different from ApsaraDB for Redis.

3. How can I connect ApsaraDB for Redis to Redis with Command Line Interface?

Using Alibaba Cloud Command Line Interface (CLI), you can run the following command to connect to the ApsaraDB for Redis over Redis:

redis-cli -h instance connection address -a Instance ID:password

Note: ApsaraDB for Redis can only be connected to an ECS Instance in the same node. This is because ApsaraDB for Redis can only be connected with intranet, and not over the Internet with hosts on other nodes.
For more information about Alibaba Cloud CLI, click here

4. Do updates on master nodes get automatically synchronized with the associated slave nodes?

Yes, updates on the master node are automatically synchronized with the associated slave node. Alibaba Cloud ApsaraDB for Redis supports asynchronous replication.

5. What is the re-connection mechanism after client time-out?

A client time-out may arise from network problems or due to any other issue with servers. Also, there is no explicit correspondence between request and response in the Redis protocol.

In the case of access time-out to ApsaraDB for Redis, you need to disconnect to avoid protocol errors and set up a connection again.

Note: Although ApsaraDB for Redis is compatible with a majority of Redis clients, some do not have an auto-reconnection mechanism. For such clients, you need to manually reconnect to the ApsaraDB for Redis when a time-out occurs.

6. Which Redis version is ApsaraDB for Redis compatible with?

Alibaba Cloud DB for Redis is compatible with Redis 2.8.19. However, a few commands are still not supported. For more details, see AsparaDB for Redis Document Center

7. Which Redis features and commands does ApsaraDB for Redis support?

ApsaraDB for Redis supports all Redis features and commands except for a few operations. You can find the list of the unsupported commands here.

8. Can I import my Redis data into ApsaraDB for Redis?

Yes, you can easily import all your Redis data into ApsaraDB for Redis. You can read the detailed import instructions here

9. Does ApsaraDB for Redis support Redis LUA scripts?

No, ApsaraDB for Redis does not support Redis LUA scripts.

10. Does ApsaraDB for Redis support "distributed clusters"?

At present, ApsaraDB for Redis instances which are 128GB or above can support distributed cluster instances. These distributed cluster instances provide larger storage capacity and higher processing capability compared to regular instances. You can get more information about ApsaraDB for Redis distributed cluster instances here.

11. Does ApsaraDB for Redis cluster instance support hash_tag?

Yes, ApsaraDB for Redis distributed cluster Instances support hash_tag. You can get more information about ApsaraDB for Redis cluster instances through the Document Center.

12. What is the relationship between ApsaraDB for Redis and Redis?

ApsaraDB for Redis is a key value cloud database service built by Alibaba Cloud and is compatible with the Redis protocol and supports a majority of the Redis commands. You can easily connect with ApsaraDB for Redis for data storage and related operations.

13. Does ApsaraDB for Redis support data persistence?

Yes, ApsaraDB for Redis extends support for data persistence by adopting memory and hard disk data storage mode. However, currently the data persistence mode/frequency is set automatically by ApsaraDB for Redis.

14. Why doesn’t my new ApsaraDB for Redis instance show zero in the beginning?

The product behavior of ApsaraDB for Redis is similar to Redis. But when a new instance is created, it generates some dictionary class system files of 1-2MB, so a fraction of storage space of the instance usually gets occupied. Hence, the usage doesn’t reflect zero in the beginning on the ApsaraDB for Redis console whenever a new ApsaraDB for Redis instance is created.

15. Does ApsaraDB for Redis support master-slave double node backup?

Yes, synchronization and failover between master and slave nodes are all managed by ApsaraDB for Redis. You don’t need to make any maintenance efforts on your own.

16. Does ApsaraDB for Redis support read-only slave node?

No. ApsaraDB for Redis adopts a master-slave structure in which slave nodes do not support read-only model.

17. Does ApsaraDB for Redis support N slave nodes for one master node?

No, currently the master and slave nodes are mapped one-to-one and work synchronously.

18. Can I customize the hash algorithm for an ApsaraDB for Redis Cluster instance?

No, ApsaraDB for Redis Cluster instance does not support the user-defined hash algorithm. It adopts the standard hash algorithm, followed by Redis Cluster.