Thank you, Naren. I'll add some more details and upload it to FAQ wiki page.
maki 2011/4/21 Narendra Sharma <narendra.sha...@gmail.com>: > Here are some more details that might help: > 1. You are right that Seeds are referred on startup to learn about the ring. > 2. It is a good idea to have more than 1 seed. Seed is not SPoF. Remember > Gossip also provides eventual consistency. So if seed is missing, the new > node may not have the correct view of the ring. However, after talking to > other nodes it will eventually have the uptodate state of the ring. > 3. In an iteration Gossiper on a node sends gossip message > - To a known live node (picked randomly) > - To a known dead node (based on some probability) > - To a seed node (based on some probability) > > Thanks, > Naren > On Wed, Apr 20, 2011 at 7:13 PM, Maki Watanabe <watanabe.m...@gmail.com> > wrote: >> >> 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 > > > > -- > Narendra Sharma > Solution Architect > http://www.persistentsys.com > http://narendrasharma.blogspot.com/ > >
