yrmcds provides an extension to memcached protocol to dump existing keys.
The general description about the text protocol is available at: https://github.com/memcached/memcached/blob/master/doc/protocol.txt
The key dump command syntax is:
keys [<prefix>]\r\n
where prefix is the prefix string of dumping keys.
If prefix is omitted, all keys will be dumped.
After this command, the client expects zero or more values, each of which is received as a text line. After all the items have been transmitted, the server sends the string
END\r\n
to indicate the end of response.
Each item sent by the server looks like this:
VALUE <key>\r\n
where key is a key having the given prefix.
The general description about the binary protocol is available at: https://code.google.com/p/memcached/wiki/MemcacheBinaryProtocol
This extension introduces a new opcode:
0x50 (Keys)
Keys Request:
- MUST NOT have extras.
- MAY have key.
- MUST NOT have value.
Successful response of Keys consists of a series of these responses:
- MUST NOT have extras.
- MUST have key.
- MUST NOT have value.
followed by an empty response (i.e., key length is 0).