incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Maki Watanabe <watanabe.m...@gmail.com>
Subject seed faq
Date Thu, 21 Apr 2011 02:13:14 GMT
I made self answered faqs on seed after reading the wiki and code.
If I misunderstand something, please point out to me.

== What are seeds? ==

Seeds, or seed nodes are the nodes which new nodes refer to on
bootstrap to know ring information.
When you add a new node to ring, you need to specify at least one live
seed to contact. Once a node join the ring, it learns about the other
nodes, so it doesn't need seed on subsequent boot.

There is no special configuration for seed node itself. In stable and
static ring, you can point non-seed node as seed on bootstrap though
it is not recommended.
Nodes in the ring tend to send Gossip message to seeds more often by
design, so it is probable that seeds have most recent and updated
information of the ring. ( Refer to [[ArchitectureGossip]] for more
details )

== Does single seed mean single point of failure? ==

If you are using replicated CF on the ring, only one seed in the ring
doesn't mean single point of failure. The ring can operate or boot
without the seed. But it is recommended to have multiple seeds in
production system to maintain the ring.



Thanks
-- 
maki

Mime
View raw message