Memcached replace Command

The Memcached replace command is used to replace the value of an existing key.

If the key does not exist, the replacement fails, and you will receive the response NOT_STORED.

Syntax:

The basic syntax format for the replace command is as follows:

replace key flags exptime bytes [noreply]
value

Parameter descriptions are as follows:

• key: The key in the key-value structure used to find the cached value.

• flags: An integer parameter that the client can use to store additional information about the key-value pair.

• exptime: The duration for which the key-value pair is stored in the cache (in seconds, 0 means forever).

• bytes: The number of bytes stored in the cache.

• noreply (optional): This parameter informs the server that no response is needed.

• value: The value to be stored (always on the second line) (can be directly understood as the value in the key-value structure).

Example

In the following example, we set:

• key → mykey

• flag → 0

• exptime → 900 (in seconds)

• bytes → 10 (number of bytes for data storage)

• value → data_value

In this example, we use the key 'mykey' and store the corresponding value 'data_value'. After execution, we replace the value of the same key with 'some_other_value'.

add mykey 0 900 10
data_value
STORED
get mykey
VALUE mykey 0 10
data_value
END
replace mykey 0 900 16
some_other_value
get mykey
VALUE mykey 0 16
some_other_value
END

Output

If the data is added successfully, the output is:

STORED

Output information descriptions are as follows:

• STORED: Output after successful save.

• NOT_STORED: Output after a failed replacement.