XLEN command in Redis is used to get the length of a stream. This is particularly useful when you need to know the number of items stored in your stream for purposes like monitoring, debugging or maintaining optimal performance.
Here's how to use
XLEN with Python's redis library:
In this example, we first connect to our local Redis instance. We add two items to the 'mystream' stream using
xadd. Then, we use
xlen to retrieve the count of items present in the stream.
XLEN, make sure that the key provided refers to a stream not a different data type, as it will result in an error.
XLENprovides the count of items in the stream, consider the potential size of your stream and handle large counts appropriately in your application logic.
XLENon non-existing keys or keys referring to data types other than streams. The command will return 0 if the provided key does not exist, but will throw an error if the key exists but does not refer to a stream.
What if I call
XLEN on a non-existing key?
XLEN command will simply return 0.
Can I use
XLEN on other data types like sets or lists?
XLEN command is specific to Redis Streams. Using it on other data types will result in an error.