Memcached replace command

Memcached replace command is used to replace the value(data value) of an existing key(key).

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

Syntax:

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

replace key flags exptime bytes [noreply]
value

The parameter description is as follows:

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

• flags: Integer parameter that can include key-value pairs and is used by the client to store additional information about the key-value pairs .

• exptime: The length of time to keep key-value pairs in the cache (in seconds, 0 means forever)

• bytes: The number of bytes stored in the cache

• noreply (optional) : This parameter tells the server that no data needs to be returned

• value: The stored value (always located in 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 of data storage)

• value → data_value

In the following examples 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, output:

STORED

Output information description:

• STORED: Output after successful saving.

• NOT_STORED: Output after the replacement fails.