cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ryan King <r...@twitter.com>
Subject Re: finding Cassandra servers
Date Wed, 03 Mar 2010 17:35:31 GMT
2010/3/3 Ted Zlatanov <tzz@lifelogs.com>:
> On Wed, 3 Mar 2010 09:04:37 -0800 Ryan King <ryan@twitter.com> wrote:
>
> RK> Something like RRDNS is no more complex that managing a list of seed nodes.
>
> How do your clients at Twitter find server nodes?  Do you just run them
> local to each node?

RRDNS + loading the token map to discover more servers. Our
implementation is open source:
http://github.com/fauna/cassandra/blob/master/lib/cassandra/cassandra.rb

> My concern is that both RRDNS and seed node lists are vulnerable to
> individual node failure.  Updating DNS when a node dies means you have
> to wait until the TTL expires, and if you lower the TTL too much your
> server will get killed.

If you combine it with a fault-tolerate thrift client and loading the
token map, it works fine.

> With seed node lists, if I get unlucky I'd be trying to hit a downed
> node in which case I may as well just use RRDNS and deal with connection
> failure from the start.

Why would you not deal with connection failure?

-ryan

Mime
View raw message