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Date: Wed, 3 Mar 2010 07:57:32 -0600
Message-ID: <1c6fcff1003030557v527c2dcbn78e1ea9f93adc328@mail.gmail.com>
Subject: Re: finding Cassandra servers
From: Gary Dusbabek <gdusbabek@gmail.com>
To: cassandra-user@incubator.apache.org
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2010/3/3 Ted Zlatanov <tzz@lifelogs.com>:
> On Mon, 01 Mar 2010 12:15:11 -0600 Ted Zlatanov <tzz@lifelogs.com> wrote:
>
> TZ> I need to find Cassandra servers on my network from several types of
> TZ> clients and platforms. =A0The goal is to make adding and removing ser=
vers
> TZ> painless, assuming a leading window of at least 1 hour. =A0The discov=
ery
> TZ> should be automatic and distributed. =A0I want to minimize management=
.
>
> TZ> Round-robin DNS with a 1-hour TTL would work all right, but I was
> TZ> wondering if Bonjour/Zeroconf is a better idea and what else should I
> TZ> consider.
>
> So... is this a dumb question or is there no good answer currently to
> discovering Cassandra servers?
>
> Ted
>
>

Nothing in the current codebase currently meets these needs.  But then
again, cassandra doesn't need the described functionality.  Zeroconf
confines itself to a single subnet (would require router configuration
to work across subnets so that multicast goes through).  RRDNS would
work, but something would need to keep that updated when servers go
away (it wouldn't be automatic).

If you can count on one of your (seed nodes) to be up, RRDNS could be
used to connect to one of them and fetch the token range list.  To do
this, create a thrift client and call describe_ring.  In older
versions you can get a jsonified endpoint map by calling
get_string_property('token map').

Hope that helps.

Gary.