How Do I Detect Big Keys and Hot Keys in Advance?¶

Method	Description
Through Big Key Analysis and Hot Key Analysis on the DCS console	See Analyzing Big Keys and Hot Keys.
By using the bigkeys and hotkeys options on redis-cli	redis-cli uses the bigkeys option to traverse all keys in a Redis instance and returns the overall key statistics and the biggest key of six data types: Strings, Lists, Hashes, Sets, Zsets, and Streams. The command is redis-cli -h <Instance connection address> -p <Port number> -a <Password> --bigkeys. In Redis 4.0 and later, you can use the hotkeys option to quickly find hot keys in redis-cli. Run this command during service running to find hot keys: redis-cli -h <Instance connection address> -p <Port number> -a <Password> --hotkeys. The hot key details can be obtained from the summary part in the returned result.

Method

Description

Through Big Key Analysis and Hot Key Analysis on the DCS console

By using the bigkeys and hotkeys options on redis-cli

redis-cli uses the bigkeys option to traverse all keys in a Redis instance and returns the overall key statistics and the biggest key of six data types: Strings, Lists, Hashes, Sets, Zsets, and Streams. The command is redis-cli -h <Instance connection address> -p <Port number> -a <Password> --bigkeys.
In Redis 4.0 and later, you can use the hotkeys option to quickly find hot keys in redis-cli. Run this command during service running to find hot keys: redis-cli -h <Instance connection address> -p <Port number> -a <Password> --hotkeys. The hot key details can be obtained from the summary part in the returned result.

Hot key analysis is not supported by DCS Redis 3.0 instances. You can configure alarms to detect hot keys.

Configure alarm rules for the Memory Usage metric of the instance nodes.
If a node has a big key, the memory usage of the node is much higher than that of other nodes. In this case, an alarm is triggered to help you find the potentially problematic key.
Configure alarm rules for the Maximum Inbound Bandwidth, Maximum Outbound Bandwidth, and CPU Usage metrics of the instance nodes.
If a node has a hot key, the bandwidth and CPU usage of the node is much higher than that of other nodes. In this case, an alarm is triggered to help you find the potentially problematic key.

last updated: 2024-05-19 03:18