Scenarios

This topic describes scenarios of local SSDs and EBS SSD volumes.

Local SSDs

• Low latency: The latency is within microseconds.
• Temporary read cache: With outstanding random read performance (4 KB, 8 KB, and 16 KB random read), local SSDs can be used as the read-only secondary database for MySQL, SQL Server, and other relational databases. Considering that the cost of memory is higher than that of SSD, local SSDs can also be used as the level-2 cache for Redis, Memcached, and other cache services.
• Single point of failure (SPOF): Local SSDs pose this risk. If redundant storage is not configured, data reliability cannot be guaranteed. EBS volumes are recommended if redundant storage is not configured at the application layer.

EBS SSD volumes

• High performance and high data reliability: The best SSDs in the industry are used as the storage medium. SSD volumes are applicable to I/O-intensive business. Each SSD volume provides long-term stability and high performance.
• Large- and medium-sized database: SSD volumes are applicable to MySQL, Redis, MongoDB, and other databases that store millions of table rows.
• Core business system: SSD volumes are applicable to I/O-intensive core business systems that have high requirements for data reliability.
• Big data analytics: SSD volumes are applicable to scenarios where TBs or PBs of distributed data are processed, such as data analysis, mining, and business intelligence.

Typical scenarios of EBS

• High-reliability data storage: EBS supports hot migration to avoid business interruption due to physical machine failure. EBS provides three replicas of data to ensure data backup and recovery. EBS is applicable to high-load core business systems.
• Elastic capacity expansion: EBS volumes can be attached to and detached from KEC instances in the same AZ without stopping or restarting the KEC instances. The capacity of EBS volumes can be configured and upgraded as required. A maximum of eight EBS volumes can be attached to a KEC instance. The total capacity of eight EBS volumes can reach up to 256 TB.