Feature Request: Support for Dalli/Rails

[benubois]

It would be great if this could work with Rails and I think for that to happen this would have to work with the Dalli gem. Currently when trying to perform any memcached operations an exception occurs:

require 'dalli'
dc = Dalli::Client.new('localhost:11211')
dc.set('abc', 123)

method server_for_key in ring.rb at line 45 method perform in client.rb at line 347 method set in client.rb at line 199

log from fatcache:

[Fri Sep  6 05:56:01 2013] fc_server.c:87 accepted c 7 on s 6
[Fri Sep  6 05:56:01 2013] fc_memcache.c:785 parsed bad req 12 res 1 type 0 state 0
00000000  80 0b 00 00 00 00 00 00  00 00 00 00 00 00 00 00   |................|
00000010  00 00 00 00 00 00 00 00                            |........|
[Fri Sep  6 05:56:01 2013] fc_core.c:81 recv on c 7 failed: Invalid argument
[Fri Sep  6 05:56:01 2013] fc_core.c:113 close c 7 on event 0005 eof 0 done 0 rb 24 sb 0: Invalid argument
[Fri Sep  6 05:56:01 2013] fc_client.c:64 close c 7 discarding pending req 12 len 24 type 0

[manjuraj]

@benubois could you paste the log file by running fatcache with log level 9 (-v 9)

[benubois]

Certainly, here it is:

[Sun Sep 22 22:13:41 2013] fc_core.c:145 event 0001 on 6
[Sun Sep 22 22:13:41 2013] fc_util.c:573 malloc(120) at 0xa8f970 @ fc_connection.c:180
[Sun Sep 22 22:13:41 2013] fc_connection.c:239 get conn 0xa8f970 c 7
[Sun Sep 22 22:13:41 2013] fc_server.c:87 accepted c 7 on s 6
[Sun Sep 22 22:13:41 2013] fc_server.c:45 accept on s 6 not ready - eagain
[Sun Sep 22 22:13:41 2013] fc_core.c:145 event 0005 on 7
[Sun Sep 22 22:13:41 2013] fc_util.c:573 malloc(224) at 0xa8f9f0 @ fc_message.c:57
[Sun Sep 22 22:13:41 2013] fc_message.c:124 get msg 0xa8f9f0 id 1 request 1 owner sd 7
[Sun Sep 22 22:13:41 2013] fc_util.c:573 malloc(8192) at 0xa8fae0 @ fc_mbuf.c:46
[Sun Sep 22 22:13:41 2013] fc_mbuf.c:99 get mbuf 0xa91ab0
[Sun Sep 22 22:13:41 2013] fc_mbuf.c:199 insert mbuf 0xa91ab0 len 0
[Sun Sep 22 22:13:41 2013] fc_connection.c:63 recv on sd 7 24 of 8144
[Sun Sep 22 22:13:41 2013] fc_memcache.c:785 parsed bad req 1 res 1 type 0 state 0
00000000  80 0b 00 00 00 00 00 00  00 00 00 00 00 00 00 00   |................|
00000010  00 00 00 00 00 00 00 00                            |........|
[Sun Sep 22 22:13:41 2013] fc_core.c:81 recv on c 7 failed: Invalid argument
[Sun Sep 22 22:13:41 2013] fc_core.c:113 close c 7 on event 0005 eof 0 done 0 rb 24 sb 0: Invalid argument
[Sun Sep 22 22:13:41 2013] fc_client.c:64 close c 7 discarding pending req 1 len 24 type 0
[Sun Sep 22 22:13:41 2013] fc_message.c:141 put msg 0xa8f9f0 id 1
[Sun Sep 22 22:13:41 2013] fc_mbuf.c:208 remove mbuf 0xa91ab0 len 24
[Sun Sep 22 22:13:41 2013] fc_mbuf.c:121 put mbuf 0xa91ab0 len 24
[Sun Sep 22 22:13:41 2013] fc_connection.c:162 put conn 0xa8f970

[manjuraj]

looks like the Dalli is trying to use binary protocol (https://github.com/mperham/dalli). fatcache only supports memcache ascii protocol.

[manjuraj]

closing this for now. feel free to reopen if you have questions

[benubois]

@manjuraj,

Makes sense, but I keep coming back to this project as memcached on SSD is such a great idea.

I think it would be a great feature and would make fatcache immediately useful to anyone using Rails.

Any thoughts on what it would take to support the binary protocol?

[manjuraj]

There is an implementation of binary memcache in the twemproxy project (https://github.com/twitter/twemproxy/commit/f2ffca7e9bdf43efe6c60143c37ef2d628bb8fc6). See twemproxy, branch - binary_memcache.

I believe it would be trivial to port this over to fatcache