ApsaraDB for MongoDB supports the following storage types: enhanced SSDs (ESSDs) and local SSDs. This topic describes the features and differences of the two storage types.
Storage type description
Storage type | Description |
ESSDs | ESSDs are developed by Alibaba Cloud based on the next-generation distributed block storage architecture. ESSDs deliver ultra-high storage performance. ESSDs are integrated with 25 Gigabit Ethernet and remote direct memory access (RDMA) technologies. ESSDs can reduce one-way latencies and process up to 1 million read and write requests at random per second. ESSDs are provided in three performance levels (PLs) as indicated on the ApsaraDB for MongoDB buy page:
Note For more information about the performance differences of the preceding disk types, see ESSDs. The performance comparison items include capacity range, maximum IOPS per disk, and maximum throughput per disk. |
Local SSDs | Local SSDs reside on the same physical host as the database engine that is run by your ApsaraDB for MongoDB instance. You can store data in local SSDs to reduce I/O latencies. |
For more information about the performance differences of the preceding storage types, see Block storage performance. The performance comparison items include maximum capacity per disk, maximum IOPS, and maximum throughput.
Comparison between the performance of ESSDs and local SSDs
Item | ESSD | Local SSD |
I/O performance | ★★★★★ Reduces I/O latencies and improves I/O performance. | ★★★★★ Reduces I/O latencies and improves I/O performance. |
Configuration flexibility | ★★★★★ Provides various configuration options and allows you to separately scale up the storage capacity. The storage capacity cannot be scaled down. | ★★★★ Provides various configuration options and allows you to scale the storage capacity. The disk capacity that you can select varies based on the instance type. |
Scaling duration | ★★★★★ Allows you to scale the storage capacity within a few minutes. | ★★★ Requires a few hours to copy data when you scale up the storage capacity. |
Scaling impact |
| Transient connections occur during the scale-out process. |
View the storage type of an ApsaraDB for MongoDB instance
Log on to the ApsaraDB for MongoDB console. In the Specification Information section of the Basic Information page of an instance, click the value of Storage Type.