Understanding gossip protocol in cassandra

[Thouraya TH <th...@gmail.com>]

Hi all,


Please, i try to undestand how gossip protocol is used in cassandra.


I read this:


“This is most critical the first time a node starts up. By default, a node
remembers other nodes it has gossiped with between subsequent restarts. *The
seed node designation has no purpose other than bootstrapping the gossip
process* for new nodes joining the cluster. Seed nodes are not a single
point of failure, nor do they have any other special purpose in cluster
operations beyond the bootstrapping of nodes.

“

I understand that the seed node starst gossip protocol and then, the new
nodes join the seed node i.e send their state informations to the seed node

Then, the seed node broadcast received informations to all nodes on the
ring ?

That’s it ?



Thank you so much for all explanations.

Best Reagrds.

Re: Understanding gossip protocol in cassandra

[selam <se...@gmail.com>]

If i remember correctly;

In real life gossip, you can not get the information before you give some.

New machine sends it's own state to seed node, seed node replys this
message with  list of other nodes and their states (end of seed node
role), then after a while (if i remember correctly gossip protocol
using one seconds interval) new machine chooses a another node from
this list by random and sends information it's own, response of this
message is a list of other machines and their states and it goes like
this.

every nodes doing this in X second interval so every machine
eventually knows other nodes and their states.

In every state, node send this information to randomly choosen node.

If i'm wrong other peoples will correct this message.



On Mon, Aug 3, 2015 at 5:27 PM, Thouraya TH <th...@gmail.com> wrote:
> Hi all,
>
>
> Please, i try to undestand how gossip protocol is used in cassandra.
>
>
> I read this:
>
>
> “This is most critical the first time a node starts up. By default, a node
> remembers other nodes it has gossiped with between subsequent restarts. The
> seed node designation has no purpose other than bootstrapping the gossip
> process for new nodes joining the cluster. Seed nodes are not a single point
> of failure, nor do they have any other special purpose in cluster operations
> beyond the bootstrapping of nodes.
>
> “
>
> I understand that the seed node starst gossip protocol and then, the new
> nodes join the seed node i.e send their state informations to the seed node
>
> Then, the seed node broadcast received informations to all nodes on the ring
> ?
>
> That’s it ?
>
>
>
> Thank you so much for all explanations.
>
> Best Reagrds.



-- 
Saygılar && İyi Çalışmalar
Timu EREN ( a.k.a selam )