# master-replica Redis Hotkey Analysis

## Background Information
URedis is based on the Least Frequently Used (LFU) algorithm and identifies the hot keys of the current instance through efficient sorting and statistical algorithms.

## Precautions
* The URedis versions that support scanning of large keys are master-replica versions 4.0, 5.0, 6.0, 7.0.
* The result files generated after hotkey analysis are retained for only 24 hours and cannot be downloaded after this period.
Only one hotkey analysis task can be executed at a time.
* Hotkey analysis will increase the load on the master instance. Before running hotkey analysis, it is important to evaluate whether it will impact the instance's performance.
* By default, hotkey analysis identifies the top 100 hotkeys. If multiple hotkeys have the same frequency, only the first scanned hotkeys will be displayed.
* Prior to conducting hotkey analysis, ensure that the configuration parameter "maxmemory-policy" is set to "allkeys-lfu" or "volatile-lfu."

## Operation Steps
1. Go to the "UMem Redis" product page.
2. Select the master-replica Redis product, find "Hotkey Analysis" in the More button, and click to confirm execution.
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3. You will automatically be redirected to the Scheduled Task Management page.
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4. After the task is successfully executed, the task status changes to success. You can then click the download button to download the hotkey analysis file.
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5. After the download is complete, you can view the hotkey analysis file. The result file is divided into two parts.
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   * **Part one**: Display detailed information of the hotkey, with a total of 3 columns. The first column is the db where the key is located, the second column is the access heat of the key, and the third column is the key name.
   * **Part two**: The number of hotkeys.