[ 
https://issues.apache.org/jira/browse/CASSANDRA-9206?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14500576#comment-14500576
 ] 

Jonathan Ellis commented on CASSANDRA-9206:
-------------------------------------------

Is processing 500 gossip messages per second per seed really that big a deal? 

> Remove seed gossip probability
> ------------------------------
>
>                 Key: CASSANDRA-9206
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-9206
>             Project: Cassandra
>          Issue Type: Improvement
>            Reporter: Brandon Williams
>            Assignee: Brandon Williams
>             Fix For: 2.1.5
>
>         Attachments: 9206.txt
>
>
> Currently, we use probability to determine whether a node will gossip with a 
> seed:
> {noformat} 
>                 double probability = seeds.size() / (double) 
> (liveEndpoints.size() + unreachableEndpoints.size());
>                 double randDbl = random.nextDouble();
>                 if (randDbl <= probability)
>                     sendGossip(prod, seeds);
> {noformat}
> I propose that we remove this probability, and instead *always* gossip with a 
> seed.  This of course means increased traffic and processing on the seed(s), 
> but even a 1000 node cluster with a single seed will only put ~1000 messages 
> per second on the seed, which is virtually nothing.  Should it become a 
> problem, the solution is simple: add more seeds.  Since seeds will also 
> always gossip with each other, this effectively gives us a poor man's 
> spanning tree, with the only cost being removing a few lines of code, and 
> should greatly improve our gossip convergence time, especially in large 
> clusters.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to