master-replica Redis Large Key Analysis

Background Information

Redis provides complex types of data structures like list, hash, zset, etc. While using these, there might be a key design that could cause an unusually large key. We provide a large key analysis tool to detect such large keys.

Notes

• Versions of URedis supporting large key scanning are master-replica version 4.0, 5.0, 6.0, 7.0.
• The result file generated from the large key analysis will be kept for only 24 hours. After 24 hours, the file will not be available for download.
• Only one key analysis task can be executed at a time.

Operation Steps

1. Go to the "UMem Redis" product page.

2. Select the master-replica Redis product, find "Large Key Analysis" in the More buttons, and click confirm for execution.

3. You can now go to the scheduled task management page to view the tasks being executed (the page will be automatically redirected after clicking confirm for task execution).

4. Wait for the task to be completed. The task status will change to successful, and then you can click the download button to download the large key analysis file.

5. After downloading, you can view the large key analysis file, which is divided into two parts.

   • Part One: Displays detailed information about the large key. There are four columns total. The first column shows the db where the key is located, the second column shows the type of key, the third column is the key name, and the fourth column is the length of the large key.
   • Part Two: Summarizes the analyzed large keys, showing the number of large keys for each type of key.

Common Questions

• Q: How long does the large key analysis task take?
  A: It depends on the number of keys in the master-replica instance. For 10 million keys, it takes about 2 minutes.

• Q: What is the standard of a large key?
  The standard for a large key is shown in the following table:

  Key Type	Large Key Standard
  list	Number of elements in the list is greater than or equal to 10,000
  hash	Number of elements in the hash is greater than or equal to 10,000
  string	Length of value is greater than or equal to 10,000
  stream	Number of elements in the stream is greater than or equal to 10,000
  set	Number of elements in the set is greater than or equal to 10,000
  zset	Number of elements in the zset is greater than or equal to 10,000

  
  If you want to adjust these standards, you can contact technical support for non-standard modifications.