Storage Analysis

Scenarios

Storage occupied by data and logs and historical changes of storage usage are important for database performance. The Storage Analysis page displays storage overview and disk space distribution of your instance. In addition, DBA Assistant can estimate the available days of your storage based on historical data and intelligent algorithms, so that you can scale up storage in a timely manner. You can also check the disk space change trend and top databases and tables.

Constraints

Currently, only replica set and cluster instances of DDS 4.0 or later are supported.

Storage Overview

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click in the upper left corner of the page and choose Databases > Document Database Service.
4. On the Instances page, click the cluster instance name.
5. In the navigation tree, choose DBA Assistant.
6. Choose Real-Time Diagnosis.
7. Click the Storage Analysis tab and check information in the Overview area.
   Figure 1 Overview
   
   • The following information is displayed:
     • Storage usage
     • Available storage
     • Average daily increase in the last week
     • Disk space distribution
       

       • Data: disk space occupied by user data
       • OpLog: disk space for storing oplogs
       • Other: disk space for storing metadata and temporary files generated by databases and the OS
   • If you are running out of storage, click Scale in the upper right corner.

Used Storage over Time

You can check the storage usage over time of your instance.

Figure 2 Disk space distribution

Top Databases and Tables

By analyzing disk space allocation and identifying the top 50 databases and tables with the largest physical file sizes, you can optimize those experiencing high usage.

Figure 3 Viewing top 50 databases and tables

• If there are more than 10,000 tables in your instance, to prevent data collection from affecting the instance performance, top databases and tables will not be counted.
• Some data of different tables in physical storage may be mixed in the same file, which is not counted in physical storage of any table. Therefore, the total physical storage of table-level data may be different from the disk usage.
• Currently, fragment space can be displayed only for instances of version 4.0. DDS 4.0 instances with WiredTiger generate disk fragments when data is updated or deleted. You can use these fragments for new data without requesting new disk space.