AnalyticDB for MySQL Elastic Cluster utilizes an architecture that separates storage resources from computing resources. An elastic I/O unit (EIU) is the unit of data that measures the storage performance of AnalyticDB for MySQL Elastic Cluster. You can use EIUs to separately scale out storage resources.

Scenarios

  • Data import: You have purchased a small amount of computing resources. A large amount of data is written, which causes I/O bottlenecks of storage nodes. In this case, you must separately scale out your storage resources.
  • Point query: You have purchased a small amount of computing resources. CPU becomes the bottleneck of storage resources. In this case, you must separately scale out your storage resources.

EIU-based storage performance metrics

Storage performance metrics are based on a mixture of I/O usage, space usage, and CPU utilization. Storage performance metrics are in proportion to the number of EIUs. The following table describes storage performance metrics of each EIU.

Metric Maximum value
Hot data storage space 4 TB
IOPS 16,800 to 50,000
Throughput 350 MB/s
CPU 24 cores

Determine the number of EIUs

When you create a cluster
AnalyticDB for MySQL provides free EIUs based on the computing resources you purchase. You do not need to specify the number of EIUs.
When you scale out a cluster
When you scale out a cluster, you can increase the number of EIUs to improve the data read/write capabilities of the cluster. For more information about the billing method of EIUs that are scaled out, see Billing methods and prices.