There must be atleast 2 brokers in isr (In Sync Replica) list of each topic partition before any node goes down which has replica, otherwise topic may go to unstable state. Or In other words, If topic partitions are in synchronization process and meanwhile a node goes down then topic may go to unstable state.
Please let me know if i am missing anything. On Mon, Apr 28, 2014 at 9:19 PM, Hanish Bansal < [EMAIL PROTECTED]> wrote: *Thanks & Regards* *Hanish Bansal*
Only a single broker needs to be online for data to be available. In your example partition 2 and 3 had copies of data on broker 0 and 1. When those two brokers went down your data was unavailable. To withstand two brokers going offline you would want to change your replication factor to 3.
One thing to keep in mind…. the replication factor is the TOTAL number of copies NOT how many follows you have, in other words the replication factor includes the leader AND the followers. On Mon, Apr 28, 2014 at 11:50 AM, Hanish Bansal < [EMAIL PROTECTED]> wrote: