Storage-optimized instances of ApsaraDB for Redis Enhanced Edition (Tair) are developed based on enhanced solid-state disks (ESSDs) and compatible with core data structures and interfaces of open source Redis. These instances can provide large-capacity, low-cost, and persistent database services. Storage-optimized instances reduce costs and improve data reliability. In addition, storage-optimized instances reduce the amount of reserved memory that is required for the forks of native Redis databases. This instance type applies to scenarios that store warm and cold data, and require compatibility with Redis, large capacity, and high access performance.
Native Redis uses volatile memory as storage media. This causes the following issues when business continuously grows and data volume rapidly increases:
- Latency and jitter occur when Redis processes a large amount of data.
- When data accumulates along with the development of business and the access volume decreases, the actual performance is more excessive than the requirements.
To resolve the preceding issues, Alibaba Cloud released storage-optimized instances that use ESSDs as the storage media. Storage-optimized instances are cost-effective and reduce up to 85% costs compared with ApsaraDB for Redis Community Edition instances. A storage-optimized instance can provide a storage capacity that reaches hundreds of TBs and higher data reliability. Storage-optimized instances reduce costs and improve data reliability. In addition, storage-optimized instances reduce the amount of reserved memory that is required for the forks of native Redis databases.
|Item||Storage-optimized instance||Hybrid-storage instances (phased out)||Open source Pika|
|Compatibility||Delivers compatibility with most commands of native Redis databases.||Delivers compatibility with all commands of native Redis databases.||Uses quite different commands from native Redis databases.|
|Data persistence||Half synchronization or asynchronous synchronization.||Asynchronous synchronization.||Asynchronous synchronization.|
|Data distribution||Stores data only in disks by using the Alibaba Cloud TairDB storage engine.||Stores the keys and values of hot data in the memory and all keys and values in disks.||Stores data only in disks by using the RocksDB storage engine.|
|Performance||Delivers a performance that is 60% of the performance of native Redis databases. The performance of storage-optimized instances for complicated data structures, such as LIST, HASH, SET, and ZSET, is 10% higher than the performance of open source Pika.||Delivers the same performance as native Redis databases for hot data in the memory. The performance for cold data is not guaranteed. The overall performance of a hybrid-storage instance depends on the distribution of cold and hot data.||Delivers a performance that is 60% of the performance of native Redis databases.|
|Scenarios||Warm data.||Data that is randomly accessed.||Warm data.|
|Costs||Saves up to 85% of costs compared with ApsaraDB for Redis Community Edition instances.||Requires 20% higher costs on average than storage-optimized instances.||Requires lower costs for on-premises physical devices but higher O&M costs.|
- Q: What is the version of the engine that is used for storage-optimized instances?
A: Storage-optimized instances use an engine that is developed by Alibaba Cloud. This engine is compatible with Redis 4.0. For more information about the support for commands, see Limits on commands supported by ApsaraDB for Redis Enhanced Edition (Tair).Note To support specific components or clients that need to detect the engine version, such as Redis-shake, storage-optimized instances retain the redis_version parameter in the response of the INFO command. The value of the redis_version parameter is 4.9.9.