Return-Path: Delivered-To: apmail-cassandra-user-archive@www.apache.org Received: (qmail 45261 invoked from network); 4 Apr 2010 20:17:01 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 4 Apr 2010 20:17:01 -0000 Received: (qmail 51769 invoked by uid 500); 4 Apr 2010 20:17:00 -0000 Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org Received: (qmail 51710 invoked by uid 500); 4 Apr 2010 20:17:00 -0000 Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@cassandra.apache.org Delivered-To: mailing list user@cassandra.apache.org Received: (qmail 51702 invoked by uid 99); 4 Apr 2010 20:17:00 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 04 Apr 2010 20:17:00 +0000 X-ASF-Spam-Status: No, hits=2.9 required=10.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_NEUTRAL X-Spam-Check-By: apache.org Received-SPF: neutral (nike.apache.org: local policy) Received: from [209.85.210.174] (HELO mail-yx0-f174.google.com) (209.85.210.174) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 04 Apr 2010 20:16:51 +0000 Received: by yxe4 with SMTP id 4so1944714yxe.28 for ; Sun, 04 Apr 2010 13:16:30 -0700 (PDT) Received: by 10.151.21.21 with SMTP id y21mr4980332ybi.192.1270412189878; Sun, 04 Apr 2010 13:16:29 -0700 (PDT) Received: from [192.168.1.176] (214.sub-75-208-42.myvzw.com [75.208.42.214]) by mx.google.com with ESMTPS id 14sm7582170gxk.3.2010.04.04.13.16.23 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 04 Apr 2010 13:16:26 -0700 (PDT) From: Joe Stump Mime-Version: 1.0 (Apple Message framework v1078) Content-Type: multipart/alternative; boundary=Apple-Mail-1-47202979 Subject: Re: Memcached protocol? Date: Sun, 4 Apr 2010 13:16:18 -0700 In-Reply-To: To: user@cassandra.apache.org References: Message-Id: <7C06EF4B-600B-4585-B791-BF0EA5F263BA@joestump.net> X-Mailer: Apple Mail (2.1078) X-Virus-Checked: Checked by ClamAV on apache.org --Apple-Mail-1-47202979 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Seems like this would be pretty easy to build on top of the proxy stuff = that was recently mentioned. I don't see a reason why you couldn't just = store key/blob-in-column to get running quickly. Might make for a pretty = interesting clustered queue system as well, which has been mentioned = before on the list as well. In other words, Cassandra is quickly becoming the hammer to everyone's = cluster nails. :) --Joe On Apr 4, 2010, at 12:47 PM, Paul Prescod wrote: > Many Cassandra implementations seem to be memcached+X migrations, and = some might be replacing memcached alone. Has anyone considered making a = protocol handler or proxy that would allow Cassandra to talk the = memached binary protocol? >=20 > jmemcached + Cassandra =3D easy migration? >=20 > I have barely started to consider the impedance mismatch issues, but = the most glaring one is that the memcached namespace is flat, whereas = Cassandra's has several levels of nesting. I think that this could be = managed through configuration files. Either the user could map all = Memcached stuff to a single ColumnFamily, or they could define a = convention for splitting their keys based on special namespace = characters like ":" or "_". The user could say how to interpret keys = without enough parts (i.e. whether to treat the missing part as the = keyspace or the columnfamily). >=20 > Paul Prescod >=20 --Apple-Mail-1-47202979 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii Seems like this would be pretty easy to build on top of the proxy stuff that was recently mentioned. I don't see a reason why you couldn't just store key/blob-in-column to get running quickly. Might make for a pretty interesting clustered queue system as well, which has been mentioned before on the list as well.

In other words, Cassandra is quickly becoming the hammer to everyone's cluster nails. :)

--Joe

On Apr 4, 2010, at 12:47 PM, Paul Prescod wrote:

Many Cassandra implementations seem to be memcached+X migrations, and some might be replacing memcached alone. Has anyone considered making a protocol handler or proxy that would allow Cassandra to talk the memached binary protocol?

jmemcached + Cassandra = easy migration?

I have barely started to consider the impedance mismatch issues, but the most glaring one is that the memcached namespace is flat, whereas Cassandra's has several levels of nesting. I think that this could be managed through configuration files. Either the user could map all Memcached stuff to a single ColumnFamily, or they could define a convention for splitting their keys based on special namespace characters like ":" or "_". The user could say how to interpret keys without enough parts (i.e. whether to treat the missing part as the keyspace or the columnfamily).

 Paul Prescod


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